--- title: "IGF-1 DES: Benefits, Side Effects, Dosage & Risks" description: "IGF-1 DES (des(1-3)IGF-1) explained: what this shortened IGF-1 is, how it works, what research shows, blood sugar and cancer cautions, WADA ban and FDA status." canonical: "https://www.vitalsvault.com/peptides/igf-1-des" last-updated: 2026-08-22 --- # IGF-1 DES: Benefits, Side Effects, Dosage & Risks > IGF-1 DES (des(1-3)IGF-1) explained: what this shortened IGF-1 is, how it works, what research shows, blood sugar and cancer cautions, WADA ban and FDA status. ![An Afro-Latina woman, 37, deep brown skin, long box braids, sits on the wooden steps of a beach boardwalk after a morning run, retying her braids…](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Fpep-igf-des.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) Peptide Guide · Growth hormone and muscle # IGF-1 DES Des(1-3)IGF-1, truncated IGF-1 IGF-1 DES is IGF-1 with three amino acids trimmed off the front. That small cut makes it ten times stronger in a dish, and the piece that was cut off inspired a medicine of its own. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) Free to join · One email when peptide care opens · Most lab results in 3–5 business days Studied forCell growth, gut tissue and muscle in laboratory research EvidenceEarly research Taken asAs prescribed by a clinician Studied forCell growth, gut tissue and muscle in laboratory research EvidenceEarly research Taken asAs prescribed by a clinician ## IGF-1 DES, in short IGF-1 DES, or des(1-3)IGF-1, is insulin-like growth factor-1 missing its first three amino acids, a form found naturally in colostrum and brain. Losing one glutamate frees it from the binding proteins that restrain IGF-1, so it is about 10 times more potent in cultured cells. It is studied for cell growth and gut repair in cell and animal research only. Medically reviewed by [Robert Lufkin, MD (opens in a new tab)](https://www.robertlufkinmd.com/) Chief Medical Officer, Vitals Vault · Updated October 29, 2026 · 21 sources ## At a glance Early research TypeTruncated IGF-1 missing the tripeptide Gly-Pro-Glu at the front[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) Found in natureIsolated from bovine colostrum, human brain and porcine uterus[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) Studied forCell growth, gut tissue repair and muscle in laboratory research[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) Key traitAbout 10 times more potent than IGF-1 in cultured cells[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) Main cautionLowers blood sugar more than IGF-1 and for longer in animals[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) AvailabilitySold on the black market. Never approved for use in people[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021) FDA statusNot approved for any use. Not covered by the October 2026 compounding policy[19](https://www.vitalsvault.com/peptides/igf-1-des#source-ncpa) SportProhibited by WADA[21](https://www.vitalsvault.com/peptides/igf-1-des#source-wada-2026) ## Before you consider IGF-1 DES - Safety No human safety study of IGF-1 DES has been published. In pigs it lowered blood sugar more than IGF-1, and approved IGF-1 can cause severe lows in children.[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label) [Side effects and safety](https://www.vitalsvault.com/peptides/igf-1-des#blood-sugar) - Legal status Not FDA approved for any use, and not among the six peptides covered by the October 29, 2026 compounding policy.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021)[19](https://www.vitalsvault.com/peptides/igf-1-des#source-ncpa) [FDA status](https://www.vitalsvault.com/peptides/igf-1-des#fda-status) - How it’s taken Sold outside medicine as an injection, with quality concerns. There is no approved product, so no clinician can prescribe it.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021) [Forms and dosage](https://www.vitalsvault.com/peptides/igf-1-des#how-taken) ## How does IGF-1 DES work? DES sends the same growth signal as IGF-1, but carrier proteins hold it back less. - ### Slips past carrier proteins In rats, most DES stayed free in the blood, while most IGF-1 was held by carrier proteins.[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) - ### Stronger in a dish In cultured cells, it is about 10 times more potent than IGF-1 at driving growth.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) - ### Reaches tissue faster In rats, more of it reached tissues like the stomach and intestine than IGF-1 did.[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) ## IGF-1 DES benefits: what it is studied for These results come from cells and animals. No clinical trials of IGF-1 DES in people have been published. 1. Lab study01 ### Cell growth In cultured cells it is generally about 10 times more potent than IGF-1. In rat olfactory bulb culture it was 3 to 5 times more potent.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[3](https://www.vitalsvault.com/peptides/igf-1-des#source-russo-1994) 2. Animal study02 ### Gut tissue In rats with much of the small bowel removed, des(1-3)IGF-1 reduced fat and nitrogen malabsorption.[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) 3. Lab study03 ### Brain cell growth In fetal rat brain cells, DES was about 4 times more potent than IGF-1 at driving DNA synthesis.[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989) ## What the research shows Early research 1. 1 · Cells in a lab Studied About 10 times more potent than IGF-1 at driving growth in cultured cells.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) Shows a mechanism 2. 2 · Animals Studied Reduced fat and nitrogen malabsorption in rats after much of the small bowel was removed.[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) Shows an effect in a body 3. 3 · PeopleNot yet No studies in people yet. The nearest data come from approved IGF-1 in children, which can cause severe low blood sugar.[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) Shows it works in people The DES literature is small and mostly from the 1990s. A review of the molecule noted that clinical opportunities had not been evaluated, though gut disease and catabolic states were suggested as possibilities.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) For human safety, the nearest data come from approved IGF-1 (mecasermin). Its label warns of severe low blood sugar and of tumors in children treated above recommended doses.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) The full guide to IGF-1 DES 10 min read · Medically reviewed by Robert Lufkin, MD ## Where IGF-1 DES came from: a cow’s first milk In 1988, a team in Adelaide was purifying growth factors from bovine colostrum, the thick first milk a cow makes after calving. Alongside IGF-1 and IGF-2 they found a third form. Its sequence matched IGF-1 exactly, except that the first three amino acids, glycine, proline and glutamate, were missing. Then they tested it on rat muscle cells. The trimmed form stimulated protein synthesis and blocked protein breakdown more strongly than full IGF-1. The authors called the roughly 10-fold jump in activity unexpected, given what was then known about how IGF-1 is built. Losing three amino acids from one end should have mattered little. It mattered a great deal. It was more than a dairy curiosity. A Swedish group isolated the same truncated IGF-1 from human fetal and adult brain, and a 1996 review added porcine uterus to the list of places it had been found. The review suggests it probably forms when IGF-1 is clipped after it is made, which means human tissue makes some des(1-3)IGF-1 on its own. That makes DES unusual among growth peptides. It was found in nature before anyone produced it in a lab, and researchers have used it since the 1990s to study how IGF-1 is held in check. Where and how the body uses it turns out to be the more important question, and it shapes everything about how an injected dose behaves.[10](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1988)[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989)[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) ## How IGF-1 DES works: one missing glutamate IGF-1 spends most of its time in the blood held by IGF-binding proteins. Those carriers keep levels steady, slow its clearance and decide how much reaches a given tissue. The glutamate at position 3 is one of the contact points they grip. The 1996 review traces most of the jump in potency to that single missing glutamate, which leaves DES binding these proteins far less. The size of the effect is large. A recombinant version made in Sweden had about 100-fold lower affinity for a binding protein from human amniotic fluid. At amounts that abolished the activity of ordinary IGF-1, that binding protein left the truncated form’s effect on fetal rat brain cells untouched. At displacing labeled IGF-1 from brain and placenta membranes, a measure of receptor binding, DES was only 1.4 to 5 times more potent than IGF-1. Freedom changes how it moves. In rats, injected des(1-3)IGF-1 stayed mostly free in plasma, cleared from the blood about four times faster than IGF-1 and spread into a much larger volume. More of its radioactive label turned up in the adrenals, brain, skin, stomach and intestine. The authors proposed that binding proteins normally hold IGF-1 back from the tissues where it acts. Think of DES as the same message with the envelope removed. It acts through the IGF-1 receptor like its parent, and in some cells the IGFs also signal through the insulin receptor. What differs is how quickly and how widely the message arrives, and that difference drives both its appeal and its risks.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989)[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991)[5](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1992) ## A local signal pulled into the bloodstream Why would the body make a version of IGF-1 that escapes its own binding proteins? The Swedish researchers who studied DES from human brain proposed an answer in 1989. Intact IGF-1, held by binding proteins in the blood, may be the hormone form that travels around the body. The truncated form may be the local form, made and used within a tissue to act on nearby cells. They framed it as a hypothesis, and it still is one. It fits the brain data. In cultured rat olfactory bulb, the part of the brain that handles smell, DES was 3 to 5 times more potent than IGF-1 at driving amino acid uptake and, unlike IGF-1, supported marked expression of neurons. Combined with another local growth factor, bFGF, the tissue’s neuron pattern looked very close to fresh olfactory bulb. If the hypothesis holds, it reframes what an injection does. A molecule the body appears to use locally, within tissues, is delivered instead into the general circulation, where binding proteins hold it back far less and it reaches more tissues than IGF-1 does. That includes the liver and muscle, the main organs that set blood sugar. It also fits how DES behaves in a dish versus an animal. In culture, the 1996 review puts it at about 10 times IGF-1’s potency. In animals the advantage was retained only in part, with selective growth effects most evident in gut tissue.[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989)[3](https://www.vitalsvault.com/peptides/igf-1-des#source-russo-1994)[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) ## IGF-1 DES for gut repair: what the rat studies found The gut has been the most consistent place for DES to show an effect. In 1994, researchers removed 70 or 80 percent of the middle small intestine in growing rats, then infused IGF-1, LR3 or des(1-3)IGF-1 under the skin for seven days. After the 70 percent resection, all three peptides significantly reduced the malabsorption of fat and nitrogen. In the same work, IGF-1 peptides increased total gut weight by up to 21 percent, mostly in the stomach and upper small intestine, partly because the remaining bowel grew longer. The authors concluded that IGF-1 peptides improve absorption after partial gut removal, most likely by enlarging the absorptive surface. Responses after the larger 80 percent resection were smaller. The 1996 review picked up on this pattern. It described selective anabolic effects most evident in gut tissue and suggested inflammatory bowel disease and catabolic states, where the body breaks down more tissue than it builds, as possible clinical uses. It also said plainly that those opportunities had not yet been evaluated. The rat tissue study fits. Label from DES reached the stomach, duodenum, small intestine and colon in greater amounts than IGF-1. Whether any of this matters for a person with a damaged gut has never been tested in a published trial.[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994)[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) ## IGF-1 DES and muscle: what the evidence covers Many people who search for IGF-1 DES want to know about muscle, and the muscle evidence comes from cells and rats. In L6 rat myoblasts, the trimmed form from colostrum raised protein synthesis and slowed protein breakdown together, and it was more potent than full IGF-1 at both. It also beat IGF-1 at stimulating DNA synthesis, a marker of cells getting ready to divide. In 1992, the Adelaide group compared DES with their new engineered analogues in the same muscle cells. In cell lines that release binding proteins, Long R3 IGF-1 and DES shared the top of the potency ranking, with plain IGF-1 at the bottom. The two molecules reach the same result by changing the same spot. LR3 swaps the glutamate at position 3 for arginine. DES removes it. Anti-doping scientists report that DES is readily available on the black market for bodybuilding. The whole-animal evidence is in rats. In diabetic rats, a week of DES infusion raised weight gain, nitrogen retention and muscle protein synthesis, and it was at least as potent as IGF-1. No study cited here measured muscle size, strength or performance in people, and a sick rat is a long way from a human training block.[10](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1988)[5](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1992)[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021)[14](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1991) ## The three amino acids that became a medicine Making des(1-3)IGF-1 in the body probably leaves a leftover. When IGF-1 is clipped, as researchers proposed happens in brain, the three amino acids that come off, glycine, proline and glutamate, form a tiny peptide called GPE. It would be easy to assume it is scrap from the process that makes the more interesting molecule. In 1989, the Swedish group that found DES in human brain tested GPE on its own. It interfered with glutamate binding at the NMDA receptor, a receptor central to learning and memory, and it strongly stimulated release of acetylcholine, a key brain messenger, from slices of rat cortex. They called GPE a novel neuroactive peptide and suggested that pieces cut from the IGF-1 precursor help regulate brain function. That fragment had a long second career. Trofinetide, an oral synthetic analog of GPE developed by Neuren Pharmaceuticals and Acadia Pharmaceuticals, was approved in the US in March 2023 for Rett syndrome in adults and children aged two and older. Rett syndrome is a rare genetic disorder of brain development that takes away speech and movement skills in early childhood. So the IGF-1 story splits in two. The trimmed growth factor stayed a research tool, with no human trial among the studies here. The three amino acids trimmed from it became the starting point for an approved medicine for a disease of the developing brain.[12](https://www.vitalsvault.com/peptides/igf-1-des#source-sara-1989)[13](https://www.vitalsvault.com/peptides/igf-1-des#source-keam-2023)[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start IGF-1 DES later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## IGF-1 DES side effects: the biggest blood sugar drop in the family If DES has a signature risk, it is low blood sugar. In the 1997 pig and marmoset study, every IGF-1 variant that escapes binding proteins lowered glucose more than IGF-1, and des(1-3)IGF-1 topped the ranking. The variants also kept glucose suppressed far longer, adding up to four to eight times more low blood sugar over four hours, even though they were cleared from the blood faster. The researchers saw this as a possible feature. Their conclusion pointed to the variants, especially des(1-3)IGF-1, as a potential add-on to insulin for people with high blood sugar. No such medicine was ever approved, but the proposal tells you how insulin-like DES behaves. A molecule once floated as a diabetes adjunct carries obvious risk for someone whose blood sugar is already normal. Human data come from natural IGF-1. A study enrolled 12 adults with type 2 diabetes for six weeks of recombinant IGF-1, though only six completed the full course, and HbA1c fell from 10.4 to 8.1 percent by the end of therapy, with significant side effects in some participants. In children on mecasermin, the label warns of severe hypoglycemia leading to seizures and ties every dose to a meal or snack. A European registry found at least one low blood sugar event in 80 of 306 patients. Low blood sugar shows up as shakiness, sweating, hunger and confusion and, if severe, seizures or loss of consciousness. Insulin or other glucose-lowering drugs could add to the risk, though no DES study has measured that, and in the mecasermin registry a history of hypoglycemia predicted future events.[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997)[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021)[15](https://www.vitalsvault.com/peptides/igf-1-des#source-moses-1996)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) ## Is IGF-1 DES safe? Growth signals and cancer risk IGF-1 tells cells to grow, divide and survive, and that message does not distinguish healthy cells from abnormal ones. In a 2004 Lancet meta-analysis of 21 studies with 3,609 cancer cases and 7,137 controls, higher circulating IGF-1 was linked to more prostate cancer and premenopausal breast cancer. The associations were modest and varied by cancer site. A natural experiment runs the other way. In an Ecuadorian community with growth hormone receptor deficiency, and so very low IGF-1, researchers following people for 22 years found one nonlethal cancer and no diabetes, against 17 percent cancer and 5 percent diabetes among control subjects. Lifelong low IGF-1 signaling came with fewer cases of both diseases. The mecasermin label reflects the same caution. It contraindicates the drug in children with cancer or a history of it and reports tumors more often at higher than recommended doses or when IGF-1 rose above the normal range. DES has never been studied in people long enough to know its own risk, and a molecule ten times more potent than IGF-1 in cells deserves at least the same respect.[9](https://www.vitalsvault.com/peptides/igf-1-des#source-renehan-2004)[16](https://www.vitalsvault.com/peptides/igf-1-des#source-guevara-aguirre-2011)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996) ## Which labs matter around IGF-1 DES Start with the system DES pushes hardest. Fasting glucose shows your blood sugar after a night without food. Fasting insulin shows how hard your pancreas works to keep it there, and it often rises years before glucose does. HbA1c is your average blood sugar over roughly three months. In the human IGF-1 diabetes study, HbA1c, average 24-hour glucose and insulin levels all fell. Read together with your history, they give a clinician general context on your glucose control. They cannot rule out episodic low blood sugar or show that DES would be safe. Someone with a history of low blood sugar sits in the group the mecasermin registry flagged as most likely to have events. For men, total PSA is a general prostate baseline, since prostate cancer is one of the clearer signals in the IGF-1 epidemiology, though no study links PSA monitoring to DES. Vitals Vault starts peptide care with a blood panel at Quest Diagnostics reviewed by a licensed clinician. With DES, the useful step is understanding your own growth and glucose axis before anything is added to it.[15](https://www.vitalsvault.com/peptides/igf-1-des#source-moses-1996)[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023)[9](https://www.vitalsvault.com/peptides/igf-1-des#source-renehan-2004) ## Is IGF-1 DES legal? Where it stands in 2026 IGF-1 DES has never been approved by FDA for any use, and anti-doping scientists describe it as never approved for use in humans. It was not among the six peptides that FDA allowed 503A pharmacies to compound under enforcement discretion on October 29, 2026, so there is no prescription pathway. Products sold online as research chemicals are not made or tested for people. The only FDA-approved IGF-1 medicine is mecasermin, sold as Increlex and approved on August 30, 2005. It is natural-sequence human IGF-1, prescribed by specialists for growth failure in children with severe primary IGF-1 deficiency. In sport, the World Anti-Doping Agency’s 2026 Prohibited List covers IGF-1 and its analogues under S2, banned at all times, and labs can detect DES in blood.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021)[19](https://www.vitalsvault.com/peptides/igf-1-des#source-ncpa)[18](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-fda)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label)[21](https://www.vitalsvault.com/peptides/igf-1-des#source-wada-2026) ## What this means for you IGF-1 DES is a real molecule your body makes, found in colostrum and brain, and three amino acids shorter than IGF-1. That small cut frees it from the binding proteins that pace IGF-1, which makes it about ten times stronger in cells and, in pigs, the most potent IGF-1 variant tested at lowering blood sugar. No human trial appears among the studies here. Its most useful legacy may be the piece it lost, the GPE fragment that led to an approved medicine for Rett syndrome. The trimmed growth factor itself remains a research tool, best at showing how much IGF-1’s brakes matter. If DES caught your eye for muscle or recovery, the better first question is what your own growth and glucose markers look like today. Where do your fasting glucose, insulin and HbA1c sit, and what would a clinician want to see before any growth signal is added?[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997)[13](https://www.vitalsvault.com/peptides/igf-1-des#source-keam-2023) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start IGF-1 DES later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## What to expect with IGF-1 DES There is no supervised path to IGF-1 DES, so the realistic process starts elsewhere. A clinician-led route begins with a history and baseline labs for glucose, insulin, HbA1c and, for men, PSA, then focuses on approved options or on the habits that move your own IGF-1. On timing, animal studies show the risk arriving first. In pigs and marmosets, the glucose drop from DES came within hours of a single injection and lasted longer than with IGF-1, while the gut effects in rats were measured after a week of continuous infusion.[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997)[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) ## Key IGF-1 DES studies - Francis et al., 1988[10](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1988) Lab study · Protein from bovine colostrum; rat muscle cells Found DES and showed it about 10 times more active than IGF-1 on muscle cells Limits: Cells only - Carlsson-Skwirut et al., 1989[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989) Lab study · Human brain and placenta membranes; fetal rat brain cells About 100-fold weaker binding-protein affinity; 4 times more potent on brain cell DNA synthesis Limits: Cells and membranes only - Ballard et al., 1991[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) Animal study · Rats given labeled IGF peptides DES stayed mostly free, cleared about four times faster and reached more tissues than IGF-1 Limits: Tracer doses in rats - Lemmey et al., 1994[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) Animal study · Growing rats after 70 or 80 percent small bowel removal After 70 percent resection, IGF-1, LR3 and DES all reduced fat and nitrogen malabsorption; responses after 80 percent were smaller Limits: Rats; seven days - Tomas et al., 1997[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) Animal study · Pigs and marmoset monkeys DES was the most potent variant tested in pigs at lowering blood glucose, beat IGF-1 in marmosets, with prolonged effect Limits: Single injections in animals - Bang et al., 2023[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) Registry of approved IGF-1 (mecasermin) · 306 children and adolescents 80 had at least one low blood sugar event; prior hypoglycemia and Laron syndrome predicted events Limits: Natural IGF-1, not DES Key studies on IGF-1 DES | Study | Design | Who | What it found | Limits | | --- | --- | --- | --- | --- | | Francis et al., 1988[10](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1988) | Lab study | Protein from bovine colostrum; rat muscle cells | Found DES and showed it about 10 times more active than IGF-1 on muscle cells | Cells only | | Carlsson-Skwirut et al., 1989[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989) | Lab study | Human brain and placenta membranes; fetal rat brain cells | About 100-fold weaker binding-protein affinity; 4 times more potent on brain cell DNA synthesis | Cells and membranes only | | Ballard et al., 1991[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) | Animal study | Rats given labeled IGF peptides | DES stayed mostly free, cleared about four times faster and reached more tissues than IGF-1 | Tracer doses in rats | | Lemmey et al., 1994[4](https://www.vitalsvault.com/peptides/igf-1-des#source-lemmey-1994) | Animal study | Growing rats after 70 or 80 percent small bowel removal | After 70 percent resection, IGF-1, LR3 and DES all reduced fat and nitrogen malabsorption; responses after 80 percent were smaller | Rats; seven days | | Tomas et al., 1997[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) | Animal study | Pigs and marmoset monkeys | DES was the most potent variant tested in pigs at lowering blood glucose, beat IGF-1 in marmosets, with prolonged effect | Single injections in animals | | Bang et al., 2023[8](https://www.vitalsvault.com/peptides/igf-1-des#source-bang-2023) | Registry of approved IGF-1 (mecasermin) | 306 children and adolescents | 80 had at least one low blood sugar event; prior hypoglycemia and Laron syndrome predicted events | Natural IGF-1, not DES | ## IGF-1 DES myths and evidence - ### IGF-1 DES is natural, so it must be safe Your body does make DES, and one hypothesis holds that it acts locally within tissues. Injected, it circulates freely, and in pigs it was the strongest IGF-1 variant tested at lowering blood sugar.[11](https://www.vitalsvault.com/peptides/igf-1-des#source-carlsson-skwirut-1989)[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991)[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) - ### DES only acts where you inject it In rats, injected labeled DES spread into a much larger volume than IGF-1, and more of its label reached the adrenals, brain, skin, stomach and intestine. It also lowered whole-body blood glucose in pigs and marmosets.[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991)[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) - ### DES is short-acting, so it is the gentler IGF-1 It clears from the blood faster than IGF-1, yet its glucose-lowering effect in animals was deeper and lasted longer. In rats, unchanged DES was still detectable in blood 24 hours after an injection into muscle.[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991)[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997)[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021) Know your baseline first 120+ lab tests at Quest, every result reviewed by a licensed clinician. Most results in 3–5 business days. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## How is IGF-1 DES taken? DES sold outside medicine is injected, and quality is a concern. Testing of black market IGF-1 analogues found oxidized, lower-quality peptide forms. There is no approved product, so no clinician can prescribe it.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021) ## IGF-1 DES dosage No study in people has tested IGF-1 DES, so there is no typical human dose to report. For context only, the table shows the FDA-labelled dose of mecasermin, the approved natural-sequence IGF-1, given twice daily with food to children with severe primary IGF-1 deficiency. Other human studies have tested recombinant natural-sequence IGF-1, but none of those doses sets a human dose for IGF-1 DES. Online DES dosing charts have no clinical trial behind them. Your clinician sets your dose for any IGF-1 medicine.[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label) ## Typical IGF-1 DES dosage No human dose of IGF-1 DES has been published: it has only been tested in cells and animals, and no FDA label, human trial or clinical review gives one. For context, the table shows the FDA label dose of mecasermin, the approved IGF-1 medicine, which a pediatric specialist prescribes. Your clinician sets the actual dose of any IGF-1 medicine. These are reference doses from FDA labels, studies in people and clinical practice reports, shown for education. They are not a recommendation or a prescription. Your dose, form and schedule should be set by a licensed clinician who knows your history and lab results. Already have a prescribed dose? The [peptide dosage calculator](https://www.vitalsvault.com/peptides/tools/dosage-calculator) turns it into the units to draw on an insulin syringe. - FDA label · Injection under the skin (mecasermin, natural-sequence IGF-1) Start 0.04 to 0.08 mg/kg; may rise by 0.04 mg/kg per dose after at least one week if tolerated, to a maximum of 0.12 mg/kg Twice daily, within 20 minutes before or after a meal or snack[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label) Children 2 years and older with severe primary IGF-1 deficiency. This is the approved IGF-1 medicine, not IGF-1 DES, and the dose does not transfer to IGF-1 DES Typical IGF-1 DES doses in people, by source | Source | Form | Amount | How often | Notes | | --- | --- | --- | --- | --- | | FDA label[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label) | Injection under the skin (mecasermin, natural-sequence IGF-1) | Start 0.04 to 0.08 mg/kg; may rise by 0.04 mg/kg per dose after at least one week if tolerated, to a maximum of 0.12 mg/kg | Twice daily, within 20 minutes before or after a meal or snack | Children 2 years and older with severe primary IGF-1 deficiency. This is the approved IGF-1 medicine, not IGF-1 DES, and the dose does not transfer to IGF-1 DES | ## Is IGF-1 DES right for you? A clinician makes the call. These are the questions they will ask first. ### It may suit - Adults curious about the GH-IGF-1 axis who want to understand the evidence before any decision - People already tracking glucose, insulin and HbA1c ### Talk to a clinician first if you are - A personal or family history of cancer - Diabetes, or taking insulin or other glucose-lowering medicine - Tested athletes (WADA prohibits IGF-1 analogues) - Pregnant or breastfeeding - Anyone under 18 or with a history of low blood sugar Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) ## Binding proteins are the brakes on IGF-1 Most IGF-1 in the blood is held by carrier proteins. In rats, they appeared to limit how much IGF-1 reached tissues. DES escapes them, and it was far more potent in cells. Pigs and marmosets showed the flip side. DES lowered blood sugar more strongly and for longer than IGF-1. For that reason it is better understood as a research tool than as a ready-made medicine.[1](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1996)[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991)[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) ### What else moves the same system 1. 01Deep sleepGrowth hormone, which drives your own IGF-1, is released mostly during deep sleep. 2. 02Resistance trainingLoading muscle is the strongest natural growth signal. 3. 03Enough protein and caloriesChronic under-eating lowers IGF-1, and adequate intake supports it. 4. 04Metabolic markersFasting glucose, fasting insulin and HbA1c show how your metabolism handles growth and insulin signals. ## Labs to check with IGF-1 DES A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment. 1. TestA baseline panel at Quest Diagnostics. 2. DecideA licensed clinician reviews your history and results. 3. RetestThe same markers again, side by side. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) - [Fasting glucoseA simple metabolic marker to retest.](https://www.vitalsvault.com/biomarkers/glucose) - [Fasting insulinShows insulin resistance earlier than glucose alone.](https://www.vitalsvault.com/biomarkers/insulin) - [HbA1cYour average blood sugar over about three months.](https://www.vitalsvault.com/biomarkers/hemoglobin-a1c) - [Total PSAA general prostate baseline for men, read by a clinician. Higher circulating IGF-1 is associated with prostate cancer risk in population studies, though PSA cannot show whether a growth factor is safe.](https://www.vitalsvault.com/biomarkers/psa-total) ## Is IGF-1 DES FDA approved? No. IGF-1 DES has never been approved by FDA for any use, and it was not among the six peptides covered by FDA’s October 29, 2026 enforcement discretion for 503A compounding. The only FDA-approved IGF-1 medicine is mecasermin (Increlex), approved in 2005 for growth failure in children with severe primary IGF-1 deficiency.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021)[19](https://www.vitalsvault.com/peptides/igf-1-des#source-ncpa)[18](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-fda)[17](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-label) ### IGF-1 DES timeline 1. 1991 Rat study shows des(1-3)IGF-1 binds few carrier proteins and clears from blood faster than IGF-1.[2](https://www.vitalsvault.com/peptides/igf-1-des#source-ballard-1991) 2. 1992 Francis and colleagues compare des(1-3)IGF-1 with new IGF-1 analogues in muscle cells.[5](https://www.vitalsvault.com/peptides/igf-1-des#source-francis-1992) 3. 1997 Pig and marmoset study finds des(1-3)IGF-1 the most potent of the IGF-1 variants tested at lowering blood glucose.[6](https://www.vitalsvault.com/peptides/igf-1-des#source-tomas-1997) 4. August 30, 2005 FDA approves mecasermin (Increlex), natural-sequence IGF-1, for children with severe primary IGF-1 deficiency.[18](https://www.vitalsvault.com/peptides/igf-1-des#source-increlex-fda) 5. 2021 French anti-doping scientists report des(1-3)IGF-1 is sold on the black market and was never approved for use in humans.[7](https://www.vitalsvault.com/peptides/igf-1-des#source-mongongu-2021) 6. 2026 WADA’s Prohibited List names IGF-1 and its analogues under S2, prohibited at all times.[21](https://www.vitalsvault.com/peptides/igf-1-des#source-wada-2026) ![A white man, 50, big-framed, grey ponytail, bushy grey moustache, plaid shirt listens on a camper step](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Ffaq-igf1-des.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) ## IGF-1 DES questions What is IGF-1 DES? IGF-1 DES, or des(1-3)IGF-1, is IGF-1 without its first three amino acids. It binds IGF-binding proteins very little, so it is about 10 times more potent than IGF-1 in cultured cells. It was never approved for human use. What is IGF-1 DES used for? In research it is used to study cell growth, gut tissue and muscle. It is sold online to people who want muscle growth, but it is not FDA-approved for that or any other use. What are the benefits of IGF-1 DES? In cells and animals it stimulated growth and protein build-up more than IGF-1 and helped gut function after bowel removal in rats. No human benefit has been shown in published trials. How does IGF-1 DES work? It activates IGF-1 receptors. Because it escapes IGF-binding proteins, more of it is free to act and it reaches tissues faster than natural IGF-1. What are the side effects of IGF-1 DES? The main concern is low blood sugar, because des(1-3)IGF-1 lowered glucose more and for longer than IGF-1 in animals. There are also cancer-related cautions that apply to IGF-1 in general. DES has no published human safety data. What is the IGF-1 DES dosage? There is no typical human dose, because IGF-1 DES has never been tested in people. The labelled IGF-1 dose in the table belongs to mecasermin, a different, approved medicine for children with severe IGF-1 deficiency, and doses from human studies of natural-sequence IGF-1 do not transfer to IGF-1 DES either. Do not use any online chart; your clinician sets your dose. IGF-1 DES vs IGF-1 LR3, which is different? Both escape IGF-binding proteins. DES is natural IGF-1 shortened by three amino acids. LR3 has an added front-end extension and arginine at position 3. In pigs, both lowered blood glucose more than IGF-1, and DES lowered it the most. Is IGF-1 DES the same as Increlex? No. Increlex (mecasermin) is natural-sequence human IGF-1. FDA approved it in 2005 for growth failure in children with severe primary IGF-1 deficiency or with growth hormone gene deletion and neutralizing antibodies to growth hormone. DES is a different, unapproved molecule. Is IGF-1 DES FDA approved or legal? It is not FDA-approved for any use, and it is not covered by FDA’s October 2026 policy on compounding six peptides. Products sold online as research chemicals are not made or tested for people. Is IGF-1 DES banned in sports? Yes. WADA’s 2026 Prohibited List names IGF-1 and its analogues in S2, prohibited in and out of competition. Can I get IGF-1 DES through Vitals Vault? No. IGF-1 DES is not an approved or compounding-eligible medicine. Vitals Vault is opening clinician-led peptide care that starts with a blood test, and you can join the peptides waitlist to hear first. ## Peptides, prescribed and measured Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first. - Prescription only - Licensed US clinicians - Quest Diagnostics labs [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## Keep reading [Full Peptide Guide](https://www.vitalsvault.com/peptides) - IGF-1 LR3A lab-modified IGF-1 that resists its binding proteins, studied in cells and animals and never approved for people. - Mechano growth factor (MGF)A splice variant of the IGF-1 gene that muscle makes after mechanical load, studied for muscle stem cell activation. - Follistatin-344A muscle-regulating protein that binds myostatin. Strong in animals. Human FS344 data come from gene therapy, not injected protein. - FDA peptide update 2026What FDA’s October 2026 decision on six peptides means for you. - CJC-1295A long-acting growth hormone releasing hormone analog, studied for raising growth hormone and IGF-1. ## Sources 1. 1. [Ballard FJ, et al. Des(1-3)IGF-I: a truncated form of insulin-like growth factor-I. Int J Biochem Cell Biol. 1996 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/8930132/) 2. 2. [Ballard FJ, et al. Plasma clearance and tissue distribution of labelled insulin-like growth factor-I (IGF-I), IGF-II and des(1-3)IGF-I in rats. J Endocrinol. 1991 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/2005410/) 3. 3. [Russo VC, et al. Des (1-3) IGF-I potently enhances differentiated cell growth in olfactory bulb organ culture. Growth Factors. 1994 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/7779409/) 4. 4. [Lemmey AB, et al. Treatment with IGF-I peptides improves function of the remnant gut following small bowel resection in rats. Growth Factors. 1994 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/7803042/) 5. 5. [Francis GL, et al. Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I indicate the relative importance of IGF-binding protein and receptor binding for enhanced biological potency. J Mol Endocrinol. 1992 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/1378742/) 6. 6. [Tomas FM, et al. IGF-I variants which bind poorly to IGF-binding proteins show more potent and prolonged hypoglycaemic action than native IGF-I in pigs and marmoset monkeys. J Endocrinol. 1997 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/9415072/) 7. 7. [Mongongu C, et al. Detection of LongR(3)-IGF-I, Des(1-3)-IGF-I, and R(3)-IGF-I using immunopurification and high resolution mass spectrometry for antidoping purposes. Drug Test Anal. 2021 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/33587816/) 8. 8. [Bang P, et al. Frequency and predictive factors of hypoglycemia in patients treated with rhIGF-1: data from the Eu-IGFD registry. J Clin Endocrinol Metab. 2023 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/37579214/) 9. 9. [Renehan AG, et al. Insulin-like growth factor (IGF)-I, IGF binding protein-3, and cancer risk: systematic review and meta-regression analysis. Lancet. 2004 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/15110491/) 10. 10. [Francis GL, et al. Insulin-like growth factors 1 and 2 in bovine colostrum. Sequences and biological activities compared with those of a potent truncated form. Biochem J. 1988 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/3390164/) 11. 11. [Carlsson-Skwirut C, et al. A comparison of the biological activity of the recombinant intact and truncated insulin-like growth factor 1 (IGF-1). Biochim Biophys Acta. 1989 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/2469478/) 12. 12. [Sara VR, et al. Identification of Gly-Pro-Glu (GPE), the aminoterminal tripeptide of insulin-like growth factor 1 which is truncated in brain, as a novel neuroactive peptide. Biochem Biophys Res Commun. 1989 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/2574573/) 13. 13. [Keam SJ. Trofinetide: first approval. Drugs. 2023 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/37191913/) 14. 14. [Tomas FM, et al. Increased weight gain, nitrogen retention and muscle protein synthesis following treatment of diabetic rats with insulin-like growth factor (IGF)-I and des(1-3)IGF-I. Biochem J. 1991 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/1710892/) 15. 15. [Moses AC, et al. Recombinant human insulin-like growth factor I increases insulin sensitivity and improves glycemic control in type II diabetes. Diabetes. 1996 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/8522066/) 16. 16. [Guevara-Aguirre J, et al. Growth hormone receptor deficiency is associated with a major reduction in pro-aging signaling, cancer, and diabetes in humans. Sci Transl Med. 2011 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/21325617/) 17. 17. [DailyMed. Increlex (mecasermin) injection, prescribing information (opens in a new tab)](https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=d5b2b0e1-c523-468d-9a0b-4ae4e4a8dbce) 18. 18. [Drugs@FDA. Increlex (BLA 021839), original approval August 30, 2005 (opens in a new tab)](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=021839) 19. 19. [NCPA. FDA grants enforcement discretion for compounding six peptides. October 29, 2026 (opens in a new tab)](https://ncpa.org/newsroom/qam/2026/10/29/fda-grants-enforcement-discretion-compounding-six-peptides) 20. 20. [FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (opens in a new tab)](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) 21. 21. [World Anti-Doping Agency. 2026 Prohibited List (S2.3 growth factors and growth factor modulators) (opens in a new tab)](https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf) Written by the Vitals Vault editorial team, medically reviewed by Robert Lufkin, MD, and updated October 29, 2026. This is general education, not medical advice. None of these peptides is FDA-approved to diagnose, treat, cure or prevent any disease, and compounded medicines are not FDA-reviewed for safety, effectiveness or quality. 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