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Peptide Guide · Growth hormone and muscle

Ipamorelin

Aib-His-D-2Nal-D-Phe-Lys-NH2

Ipamorelin was described in 1998, a year before scientists announced ghrelin, the stomach hormone it imitates. In pigs, it released growth hormone without the stress-hormone surge its older cousins caused.

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Studied for
Growth hormone release, body composition and gut motility
Evidence
Early human data
Taken as
As prescribed by a clinician
Studied for
Growth hormone release, body composition and gut motility
Evidence
Early human data
Taken as
As prescribed by a clinician
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Ipamorelin, in short

Ipamorelin is a five-amino-acid peptide that mimics ghrelin, binding a receptor on the pituitary gland to trigger a short pulse of the body’s own growth hormone. It was designed to do this without raising stress hormones such as cortisol. It is studied for growth hormone release and, in one trial, gut recovery after surgery, with only early human data so far.

Medically reviewed by Robert Lufkin, MD (opens in a new tab)

Chief Medical Officer, Vitals Vault · Updated October 29, 2026 · 11 sources

At a glance

Early human data
Type
Synthetic pentapeptide, a growth hormone secretagogue1
Receptor
The ghrelin-type growth hormone secretagogue receptor on the pituitary1
Developed by
Novo Nordisk, reported in 19981
Studied for
Growth hormone release; postoperative ileus (gut paralysis after surgery)13
Half-life in people
About 2 hours after intravenous infusion in healthy men2
FDA status
Not approved for any use9
Sport
Growth hormone secretagogues are prohibited by WADA11

Before you consider Ipamorelin

  • Safety

    A surgery trial of 117 patients found it well tolerated. FDA cites a report of serious adverse events, including death, when it was given intravenously for gut motility.39

    Side effects and safety
  • Legal status

    Not FDA approved for any use, and not one of the six peptides in the October 2026 enforcement-discretion policy.910

    FDA status
  • How it’s taken

    Published studies gave it by intravenous infusion. Pharmacy products are injected under the skin, a route with little published safety data.239

    Forms and dosage

How does Ipamorelin work?

Ipamorelin asks the pituitary to release growth hormone instead of supplying it.

  • Copies a hunger hormone

    Tests with blocking drugs showed it releases growth hormone the way ghrelin, a hunger hormone, does.1

  • Stays selective

    In pigs, older peptides of this class raised stress hormones. Ipamorelin did not, even at over 200 times the effective dose.1

  • Makes one short pulse

    In healthy men, an infusion caused one burst of growth hormone that peaked in about 40 minutes and then faded.24

Ipamorelin benefits: what it is studied for

Human evidence for ipamorelin is thin: hormone levels in volunteers and one surgery trial that did not show a benefit. The rest is animal work.

  1. Human study01

    Growth hormone release

    In a dose-escalation study of eight healthy men per dose level, ipamorelin released growth hormone at every dose tested, in a predictable, dose-related way.2

  2. Human study02

    Gut recovery after surgery

    In a 117-patient phase 2 trial for postoperative ileus, ipamorelin was well tolerated, but time to a first tolerated meal (25.3 versus 32.6 hours) was not significantly different from placebo.3

  3. Animal study03

    Bone growth in rats

    In adult female rats given ipamorelin for 15 days, bone growth and body weight rose with the dose. IGF-1 and bone markers did not change.7

What the research shows

Early human data
  1. 1 · Cells in a lab Studied

    In rat pituitary cells, it released growth hormone the way GHRP-6 does.1

    Shows a mechanism

  2. 2 · Animals Studied

    In pigs, it raised growth hormone without raising stress hormones. In adult rats, bone growth rose with the dose.17

    Shows an effect in a body

  3. 3 · People Studied

    In healthy men it released growth hormone in a dose-related way. A 117-patient surgery trial found no significant benefit over placebo.23

    Shows it works in people

Ipamorelin has a clean pharmacology story and a thin clinical one. Animal work showed selectivity, a volunteer study mapped how it behaves in the body, and a phase 2 trial in surgical patients found it was well tolerated without proving a benefit. None of the studies cited here is a large trial of ipamorelin for body composition, sleep or aging.123

The full guide to Ipamorelin

9 min read · Medically reviewed by Robert Lufkin, MD

In this guide

  1. 1A key cut before anyone found the lock
  2. 2How ipamorelin works on the growth hormone system
  3. 3The cortisol test that made ipamorelin famous
  4. 4Ipamorelin for the gut: the trial that tested it
  5. 5Ipamorelin benefits for muscle, bone and body composition
  6. 6Why two people can respond so differently
  7. 7Ipamorelin vs CJC-1295, GHRP-6 and other secretagogues
  8. 8Ipamorelin side effects and safety
  9. 9The labs that matter with a growth hormone secretagogue
  10. 10Where ipamorelin stands in 2026
  11. 11What this means for you
  12. 12What to expect
  13. 13Key studies
  14. 14Myths and evidence

01 / 11

A key cut before anyone found the lock

Ipamorelin was built to fit a lock that, at the time, had no known owner. In the years before ipamorelin, chemists made small synthetic molecules that reliably pushed the pituitary gland to release growth hormone. They worked, yet nobody knew which natural hormone they were imitating. Drug hunters had cut a key before anyone had seen the door it was meant for.

In 1996, a team at Merck cloned the receptor these molecules bind, on the pituitary and in the hypothalamus of pigs and people. They wrote that the drugs seemed to mimic a hormone nobody had discovered yet. Three years later, Japanese researchers found it in the stomach: a 28-amino-acid peptide they named ghrelin, from ghre, a Proto-Indo-European root meaning to grow.

Ipamorelin landed in the middle of that story. In 1998, a year before ghrelin had a name, researchers at Novo Nordisk described it in the European Journal of Endocrinology as the first selective growth hormone secretagogue. It came out of a large chemistry program that trimmed the central two amino acids from an older compound called GHRP-1, leaving a chain of five.

That word, selective, is what ipamorelin’s reputation still rests on, far more than its slim clinical record. To see why selectivity mattered so much to the people who made it, you need to know what the older molecules in this family did besides release growth hormone.561

02 / 11

How ipamorelin works on the growth hormone system

Your pituitary takes instructions on growth hormone from more than one direction. Growth hormone releasing hormone, or GHRH, from the hypothalamus pushes release. Somatostatin holds it back. Ghrelin adds a third input through its own receptor, the growth hormone secretagogue receptor. Ipamorelin plugs into that third input, so it works one step upstream of growth hormone and never supplies the hormone itself.

The Novo Nordisk team proved the route with blocking drugs. When they used antagonists for each pathway, ipamorelin behaved like GHRP-6 and released growth hormone through a GHRP-type receptor, the family ghrelin turned out to own. In rat pituitary cells and in live rats and pigs, its potency and peak effect were close to GHRP-6.

In people, the effect is a single wave. In 1999, healthy men received ipamorelin infusions at five dose levels, eight men per level. Each infusion produced one episode of growth hormone release that peaked at about 40 minutes and then declined to negligible levels. Ipamorelin itself had a half-life of about 2 hours, and the response scaled with the dose.

Because the pituitary is releasing its own stores, the body’s normal brakes stay on. Reviews of the whole secretagogue class describe pulsatile release that remains subject to negative feedback, which can prevent the very high growth hormone levels that injected hormone can produce. Reviewers count that preserved feedback among the class’s potential advantages, though it is a brake, not a guarantee.124

When they used antagonists for each pathway, ipamorelin behaved like GHRP-6 and released growth hormone through a GHRP-type receptor, the family ghrelin turned out to own.

03 / 11

The cortisol test that made ipamorelin famous

The experiment that defined ipamorelin was run in conscious pigs. There, the older peptides GHRP-6 and GHRP-2 raised growth hormone and also pushed up ACTH and cortisol, the body’s main stress hormones. Ipamorelin raised growth hormone alone. Its effect on ACTH and cortisol was no different from that of GHRH, even at doses more than 200 times higher than the dose needed for half its growth hormone effect.

The authors used an unusual phrase for a journal paper. They called the result very surprising. None of the peptides they tested moved FSH, LH, prolactin or TSH, so the cortisol finding was the one thing that separated ipamorelin from its relatives, and it gave it a selectivity for growth hormone similar to GHRH itself.

Why care about cortisol? People interested in growth hormone usually want what it does for muscle, fat and repair. Cortisol, over time, tends to pull the other way: it breaks down protein and raises blood sugar. A peptide that asks for growth hormone without sounding the stress alarm is, in principle, a cleaner request.

One caution keeps this honest. The cortisol data that built ipamorelin’s reputation came from swine. The human studies cited on this page measured growth hormone and gut recovery, and none of them reports a head-to-head cortisol comparison in people. Without human cortisol data in these sources, selectivity in people remains an inference.1

04 / 11

Ipamorelin for the gut: the trial that tested it

Ghrelin is famous for hunger, and it also moves the gut. That made ipamorelin a candidate for postoperative ileus, the frustrating days after abdominal surgery when the bowel stops moving, patients cannot eat, and hospital stays stretch out. It is also the use behind the randomized human efficacy trial cited here.

The animal work looked encouraging. In a 2009 rat model of postoperative ileus, a single dose of ipamorelin shortened the time to the first bowel movement. Repeated dosing over two days went further, raising stool output, food intake and body weight gain compared with saline. The authors suggested it might ease symptoms in surgical patients.

Then came people. A phase 2 trial enrolled 117 adults having small or large bowel resection, with 114 included in the analysis. They received intravenous ipamorelin or placebo for up to seven days in hospital. Median time to a first tolerated solid meal was 25.3 hours on ipamorelin and 32.6 hours on placebo, a gap that did not reach statistical significance.

Adverse events were common in both groups, as you would expect after major surgery, and slightly less frequent on ipamorelin (87.5% versus 94.8%). The authors concluded it was well tolerated and showed no significant difference on the main or secondary outcomes. They also noted the study was small and mixed many underlying conditions, which leaves the question open more than closed.83

05 / 11

Ipamorelin benefits for muscle, bone and body composition

Most people searching for ipamorelin want to know about muscle, fat, sleep and recovery. This is where the gap between reputation and record is widest, so it helps to separate what was measured in animals, what was measured in people, and what is borrowed from the wider class of growth hormone secretagogues.

Novo Nordisk’s own animal work came first. In adult female rats given ipamorelin for 15 days, the growth rate of the shin bone rose with dose, from 42 micrometers a day on vehicle to 52 at the highest dose, alongside a clear gain in body weight. Oddly, total IGF-1 did not change, nor did blood markers of bone building and breakdown.

In people, the evidence comes from reviews of the secretagogue family as a whole. The 2018 Sexual Medicine Reviews analysis lists possible effects including better lean mass in wasting and obesity, lower bone turnover, more fat-free mass and better sleep. The same authors stress that few long-term, rigorously controlled studies exist for any of these drugs.

Put together, ipamorelin reliably releases growth hormone in people, and growth hormone has well-known effects on body composition. None of the studies cited here shows that ipamorelin itself builds muscle, burns fat or improves sleep in adults. Those claims borrow from the hormone and from the class.74

In adult female rats given ipamorelin for 15 days, the growth rate of the shin bone rose with dose, from 42 micrometers a day on vehicle to 52 at the highest dose, alongside a clear gain in body weight.

06 / 11

Why two people can respond so differently

Buried in the 1999 volunteer study is a finding that deserves more attention than it gets. The researchers modeled two things separately: how the body handles ipamorelin, and how strongly the pituitary answers it. The variation between people was larger for the answer than for the drug handling.

Put simply, how the men’s bodies handled ipamorelin varied less than how much growth hormone their pituitaries released in response. The signal arrived at the door in roughly similar shape. The size of the reply varied more.

That fits what endocrinologists already know about growth hormone. The pituitary’s output depends on its surroundings: deep sleep, body fat, insulin, age and the balance of GHRH and somatostatin. A secretagogue can only amplify a system that is ready to answer. That reading is a hypothesis, since the study did not set out to test it.

The practical lesson is that the context around a growth hormone secretagogue may matter as much as the molecule. Two people on the same prescription can have very different results. The study did not identify what drives those differences, and no test predicts an individual’s response, though sleep, body fat and metabolic health are reasonable places for a clinician to start looking.24

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 Ipamorelin later.

Start with 120+ lab tests · $99Get early access to peptide care

Full refund before your blood draw · No membership

07 / 11

Ipamorelin vs CJC-1295, GHRP-6 and other secretagogues

Ipamorelin is often discussed as one member of a crowded family, so it helps to place it. GHRP-6 and GHRP-2 act on the same ghrelin-type receptor. In the 1998 pig work, GHRP-2 was more potent but produced a smaller peak, GHRP-6 matched ipamorelin closely, and both of the older peptides raised ACTH and cortisol where ipamorelin did not.

CJC-1295 sits on the other arm of the system. It is a modified form of GHRH and acts on the GHRH receptor, the same pituitary cells reached by a different door. Sermorelin and tesamorelin are also GHRH analogs. MK-677 is an oral, non-peptide molecule that, like ipamorelin, acts at the ghrelin receptor.

That is why ipamorelin and CJC-1295 are so often paired online. The logic is physiological: push from the GHRH side, add the ghrelin input, and the pituitary may answer more strongly than to either alone. None of the studies cited on this page tested that pairing, so treat the combination as a hypothesis.14

08 / 11

Ipamorelin side effects and safety

The best human safety data come from the surgical trial, where intravenous ipamorelin for up to seven days was well tolerated and adverse events were no more common than on placebo. That is reassuring for a short hospital course. It says little about months of use at home.

Reviews of the secretagogue class add one consistent concern. Growth hormone lowers insulin sensitivity, so blood glucose can rise. The same reviewers note that long-term evidence is limited and call for more study of cancer incidence and mortality. Growth hormone and IGF-1 encourage cell growth, which is why a cancer history deserves a careful conversation.

FDA’s compounding safety page goes further. It cites the risk of the body forming antibodies to the peptide, the difficulty of characterizing a molecule built from unnatural amino acids, and a report of serious adverse events, including death, in a study that gave ipamorelin intravenously for gut motility. Those concerns are part of why FDA has not opened compounding for it.

The practical risk for most people is the vial. Products sold online as research chemicals are not made for human use, and peptide purity depends on the facility. People with diabetes or prediabetes, a cancer history, heart or kidney disease, or a pregnancy should talk to a clinician first, and tested athletes should assume it is banned.349

Growth hormone and IGF-1 encourage cell growth, which is why a cancer history deserves a careful conversation.

09 / 11

The labs that matter with a growth hormone secretagogue

Because the clearest known downside of raising growth hormone is on blood sugar, the labs most relevant to that concern are metabolic. Fasting glucose is the simplest snapshot. HbA1c shows your average blood sugar over roughly three months, so it catches a slow drift that a single morning reading can miss.

Fasting insulin adds context. Higher insulin with a normal glucose can be consistent with the pancreas working harder to keep sugar in range as insulin sensitivity falls, though it is not diagnostic on its own and needs a clinician to interpret. The secretagogue reviews flag higher blood glucose tied to reduced insulin sensitivity, which is the concern these markers speak to.

eGFR, the estimated filtration rate of your kidneys, adds a general baseline of kidney function. None of this is a validated ipamorelin monitoring panel; it is baseline context that a clinician reads alongside your history. Vitals Vault starts peptide care with a blood panel, a licensed clinician reviews it with your history, and a retest shows which way you are moving.4

10 / 11

Where ipamorelin stands in 2026

Ipamorelin is not an approved drug. On September 29, 2023, FDA placed ipamorelin acetate in category 2 of bulk substances under its 503B interim policy, the group it flags for significant safety risks. It is not one of the six peptides covered by FDA’s October 2026 enforcement-discretion policy for 503A pharmacies.

Sport has its own rule. The World Anti-Doping Agency prohibits growth hormone secretagogues, including ghrelin mimetics like ipamorelin, at all times, so anyone in tested competition should treat it as banned.91011

11 / 11

What this means for you

Ipamorelin is an elegant piece of chemistry. It asks the pituitary for a single, short pulse of growth hormone, and in pigs it did so without the stress-hormone surge its older cousins caused. In people, it releases growth hormone predictably. The randomized efficacy trial cited here, for gut recovery after surgery, did not beat placebo, and no study cited here shows the body composition results people hope for.

If you are curious about it, start with what shapes growth hormone release anyway: sleep, visceral fat, insulin and training. A baseline of glucose, HbA1c and insulin gives a clinician metabolic context. It cannot tell you whether your growth hormone is low; that takes a targeted endocrine evaluation, usually a stimulation test.123

A baseline of glucose, HbA1c and insulin gives a clinician metabolic context.

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 Ipamorelin later.

Start with 120+ lab tests · $99Get early access to peptide care

Full refund before your blood draw · No membership

What to expect with Ipamorelin

In the volunteer study, growth hormone peaked about 40 minutes after an infusion and faded within hours, and ipamorelin’s own half-life was about 2 hours. Any felt effect therefore depends on what that repeated pulse does downstream, which in the wider secretagogue literature takes weeks to show in body composition, if it shows at all.

A responsible start is a health history, a baseline of glucose, HbA1c and insulin, and a clinician’s view on whether a secretagogue makes sense for you. A retest of the same markers is how you see whether your blood sugar is holding steady.24

Key Ipamorelin studies

  • Raun et al., 19981

    Laboratory and animal pharmacology · Rat pituitary cells, rats and pigs

    Released growth hormone like GHRP-6 without raising ACTH or cortisol, even at over 200 times the half-effective dose

    Limits: Animal data; cortisol not compared in people

  • Johansen et al., 19997

    Animal study, 15 days · Adult female rats

    Faster longitudinal bone growth and body weight gain, rising with dose

    Limits: Rats; IGF-1 and bone markers did not change

  • Gobburu et al., 19992

    Dose-escalation study · Healthy men, 8 per dose level, 5 levels

    One growth hormone pulse peaking near 40 minutes; half-life about 2 hours

    Limits: Single infusions; no outcomes beyond hormone levels

  • Venkova et al., 20098

    Animal model of postoperative ileus · Rats after abdominal surgery

    Faster first bowel movement; repeated dosing raised food intake and weight gain

    Limits: Rodent model

  • Beck et al., 20143

    Randomized, double-blind, placebo-controlled phase 2 · 117 adults after bowel resection (114 analyzed)

    Well tolerated; first tolerated meal at 25.3 vs 32.6 hours, not significant

    Limits: Small; mixed conditions; intravenous use only

Key studies on Ipamorelin
StudyDesignWhoWhat it foundLimits
Raun et al., 19981Laboratory and animal pharmacologyRat pituitary cells, rats and pigsReleased growth hormone like GHRP-6 without raising ACTH or cortisol, even at over 200 times the half-effective doseAnimal data; cortisol not compared in people
Johansen et al., 19997Animal study, 15 daysAdult female ratsFaster longitudinal bone growth and body weight gain, rising with doseRats; IGF-1 and bone markers did not change
Gobburu et al., 19992Dose-escalation studyHealthy men, 8 per dose level, 5 levelsOne growth hormone pulse peaking near 40 minutes; half-life about 2 hoursSingle infusions; no outcomes beyond hormone levels
Venkova et al., 20098Animal model of postoperative ileusRats after abdominal surgeryFaster first bowel movement; repeated dosing raised food intake and weight gainRodent model
Beck et al., 20143Randomized, double-blind, placebo-controlled phase 2117 adults after bowel resection (114 analyzed)Well tolerated; first tolerated meal at 25.3 vs 32.6 hours, not significantSmall; mixed conditions; intravenous use only

Ipamorelin myths and evidence

  • Ipamorelin is just growth hormone in a different form

    It contains no growth hormone. It binds the ghrelin-type receptor on the pituitary and prompts a pulse of your own growth hormone, which the body’s feedback still controls.14

  • Ipamorelin is proven to build muscle and burn fat

    None of the studies cited here shows that in adults. The muscle and fat claims come from growth hormone itself and from reviews of the whole secretagogue class, which note few long, rigorous studies.4

  • Ipamorelin has zero side effects because it does not raise cortisol

    The cortisol finding came from pigs. In people, the class carries a concern for higher blood sugar, and FDA cites antibody risk and serious adverse events with intravenous use. Long-term safety is poorly characterized.149

  • Ipamorelin worked for gut recovery after surgery

    It helped in rats. In the 117-patient human trial, time to a first tolerated meal was shorter on ipamorelin but not significantly different from placebo.83

On this page

  1. A key cut before anyone found the lock
  2. How ipamorelin works on the growth hormone system
  3. The cortisol test that made ipamorelin famous
  4. Ipamorelin for the gut: the trial that tested it
  5. Ipamorelin benefits for muscle, bone and body composition
  6. Why two people can respond so differently
  7. Ipamorelin vs CJC-1295, GHRP-6 and other secretagogues
  8. Ipamorelin side effects and safety
  9. The labs that matter with a growth hormone secretagogue
  10. Where ipamorelin stands in 2026
  11. What this means for you
  12. What to expect
  13. Key studies
  14. Myths and evidence

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

How is Ipamorelin taken?

In published studies, ipamorelin was given by intravenous infusion. Pharmacy-prepared products, where a prescriber chooses to use them, are injected under the skin. That route has little published safety data, which FDA noted on its compounding page. Form and schedule are a prescriber’s decision.239

Ipamorelin dosage

Ipamorelin has no FDA-approved dose. In people, it has only been given as weight-based infusions into a vein in research settings: single infusions in healthy men, and twice-daily infusions for up to a week in a hospital trial after bowel surgery. The dosage table lists those doses. No published trial has tested injections under the skin at home, and your clinician sets your dose.23

Typical Ipamorelin dosage

Ipamorelin has no FDA-approved dose. The only published human doses are weight-based infusions into a vein: single infusions in healthy men, and twice-daily infusions for up to a week in adults recovering from bowel surgery. No trial has tested injections under the skin. A clinician sets the actual dose.

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 turns it into the units to draw on an insulin syringe.

  • Human trial · Infusion into a vein over 15 minutes

    4.21 to 140.45 nmol/kg

    Single dose2

    Healthy men, eight per dose level; growth hormone rose at every dose

  • Human trial · Infusion into a vein

    0.03 mg/kg

    Twice daily for up to 7 days3

    Adults in hospital after bowel resection; well tolerated, no clear benefit over placebo for gut recovery

Typical Ipamorelin doses in people, by source
SourceFormAmountHow oftenNotes
Human trial2Infusion into a vein over 15 minutes4.21 to 140.45 nmol/kgSingle doseHealthy men, eight per dose level; growth hormone rose at every dose
Human trial3Infusion into a vein0.03 mg/kgTwice daily for up to 7 daysAdults in hospital after bowel resection; well tolerated, no clear benefit over placebo for gut recovery

Is Ipamorelin right for you?

A clinician makes the call. These are the questions they will ask first.

It may suit

  • Adults curious about growth hormone physiology who want a clinician to look at sleep, body composition and labs first
  • People who want a baseline and a retest of blood sugar and insulin

Talk to a clinician first if you are

  • A personal history of cancer or a tumor (growth hormone and IGF-1 promote cell growth)
  • Diabetes, prediabetes or any glucose-lowering medicine
  • Pregnant or breastfeeding
  • Tested athletes (WADA prohibits growth hormone secretagogues)
  • Heart or kidney disease

Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest.

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Ipamorelin vs CJC-1295

Ipamorelin vs CJC-1295
AttributeIpamorelinCJC-1295
What it isA ghrelin-mimicking secretagogue (five amino acids)A growth hormone releasing hormone analog (GHRH-based)
ReceptorGhrelin-type receptorGHRH receptor
Duration in studiesShort; half-life about 2 hoursShort without DAC; days with DAC
FDA statusNot approvedNot approved

Growth hormone is a rhythm, not a level

The body does not release growth hormone steadily. The pituitary sends it out in pulses, with the largest one in deep sleep. Sleep, body fat, insulin and age all change how big a pulse the pituitary will give.

A secretagogue also keeps negative feedback in place, which reviewers list as one potential advantage over injecting growth hormone itself.4

What else moves the same system

  1. 01Protect deep sleepThe biggest natural growth hormone pulse arrives in the first hours of deep sleep.
  2. 02Train with resistanceLifting heavy raises growth hormone acutely and builds the muscle that growth hormone acts on.
  3. 03Watch visceral fat and insulinExcess belly fat and high insulin both blunt growth hormone release, so fasting insulin is worth knowing.
  4. 04Check glucoseGrowth hormone secretagogues can raise blood sugar by lowering insulin sensitivity, so a baseline helps.

Labs to check with Ipamorelin

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
  • Fasting glucoseA simple metabolic marker to retest.
  • HbA1cYour average blood sugar over about three months.
  • Fasting insulinShows insulin resistance earlier than glucose alone.
  • Kidney function (eGFR)Peptides are cleared through the kidneys, so a baseline is useful.

Is Ipamorelin FDA approved?

No. Ipamorelin is not FDA-approved for any use. FDA’s compounding safety page lists ipamorelin acetate in category 2 of the bulk drug substances under the 503B interim policy, added September 29, 2023. It cites immunogenicity risk, the complexity of characterizing a peptide with unnatural amino acids, and serious adverse events, including death, in a study that gave ipamorelin intravenously for gut motility. Ipamorelin is not one of the six peptides covered by the October 2026 enforcement-discretion policy.910

Ipamorelin timeline

  1. 1998

    Novo Nordisk researchers describe ipamorelin as the first selective growth hormone secretagogue.1

  2. 1999

    Pharmacokinetic and pharmacodynamic modeling in healthy male volunteers.2

  3. 2014

    Phase 2 trial in 117 bowel-surgery patients reports good tolerability and no significant benefit for postoperative ileus.3

  4. September 29, 2023

    FDA places ipamorelin acetate in category 2 under the 503B interim policy, citing safety risks.9

An East Asian woman, 53, medium, long silver-black hair, jade pendant writes at a tea-house table

Ipamorelin questions

What is ipamorelin used for?

Ipamorelin is studied for prompting growth hormone release and, in one trial, for gut recovery after surgery. It is not FDA-approved to treat any condition.

What are the benefits of ipamorelin?

It released growth hormone in healthy men and was designed to avoid raising cortisol. A phase 2 trial for postoperative ileus did not show a significant benefit over placebo. Claims about body composition, sleep or anti-aging rest mostly on the wider secretagogue literature.

How does ipamorelin work?

It binds the ghrelin-type growth hormone secretagogue receptor on the pituitary and triggers a pulse of growth hormone. The body’s own feedback still controls the pulse.

What are the side effects of ipamorelin?

In a seven-day surgery trial it was well tolerated. The secretagogue class carries some concern for higher blood sugar, and FDA flags immunogenicity and a report of serious adverse events, including death, with intravenous use. Long-term data are limited.

What is the ipamorelin dosage?

There is no FDA-approved dose. Human studies gave ipamorelin as weight-based infusions into a vein, once in healthy men and twice daily for up to a week after bowel surgery. Your clinician sets your dose.

Ipamorelin vs CJC-1295: what is the difference?

Ipamorelin mimics ghrelin and acts on the ghrelin-type receptor. CJC-1295 is built on growth hormone releasing hormone and acts on the GHRH receptor. They hit different receptors on the same cells, which is why they are often discussed together.

Is ipamorelin FDA approved?

No. Ipamorelin is not FDA-approved for any use. FDA lists ipamorelin acetate in category 2 for 503B compounding because of safety concerns, and it is not covered by the October 2026 policy for six other peptides.

Is ipamorelin legal in the US?

It is not an approved drug, and FDA has not cleared it for compounding under its October 2026 policy. Vials sold online as "research use only" are not made for people.

Is ipamorelin banned in sports?

Yes. The World Anti-Doping Agency prohibits growth hormone secretagogues in and out of competition.

Can I get ipamorelin through Vitals Vault?

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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.

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Keep reading

Full Peptide Guide
  • CJC-1295A long-acting growth hormone releasing hormone analog, studied for raising growth hormone and IGF-1.
  • SermorelinA 29-amino-acid fragment of growth hormone releasing hormone, once FDA-approved as Geref and since discontinued.
  • TesamorelinAn FDA-approved growth hormone releasing factor analog (Egrifta) for excess abdominal fat in adults with HIV-associated lipodystrophy.
  • GHRP-2A six-amino-acid ghrelin-receptor agonist that triggers a sharp pulse of growth hormone. Used in Japanese diagnostic research.
  • MK-677An oral, non-peptide ghrelin-receptor agonist that raises growth hormone and IGF-1. FDA lists a heart failure concern.

Sources

  1. 1. Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998 (opens in a new tab)
  2. 2. Gobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999 (opens in a new tab)
  3. 3. Beck DE, et al. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014 (opens in a new tab)
  4. 4. Sigalos JT, et al. The safety and efficacy of growth hormone secretagogues. Sex Med Rev. 2018 (opens in a new tab)
  5. 5. Howard AD, et al. A receptor in pituitary and hypothalamus that functions in growth hormone release. Science. 1996 (opens in a new tab)
  6. 6. Kojima M, et al. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999 (opens in a new tab)
  7. 7. Johansen PB, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999 (opens in a new tab)
  8. 8. Venkova K, et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. J Pharmacol Exp Ther. 2009 (opens in a new tab)
  9. 9. 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)
  10. 10. NCPA. FDA grants enforcement discretion for compounding six peptides. October 29, 2026 (opens in a new tab)
  11. 11. World Anti-Doping Agency. Prohibited List (opens in a new tab)

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. Talk to a licensed clinician before starting any treatment.

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