TyG Index (Triglyceride-Glucose Index) Biomarker Testing
The TyG Index estimates insulin resistance using fasting triglycerides and glucose, and you can order it through Vitals Vault with Quest labs.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Your TyG Index (Triglyceride-Glucose Index) is a calculated number that uses two familiar labs—fasting triglycerides and fasting glucose—to estimate how resistant your body may be to insulin.
It is not a diagnosis by itself, but it can help you spot an early metabolic pattern that sometimes shows up before diabetes is obvious on standard screening.
Because it combines fats (triglycerides) and sugar (glucose) into one index, it can be a practical way to track cardiometabolic risk over time, especially when you compare it with other markers on your panel.
Do I need a TyG Index test?
You may want a TyG Index if you are trying to understand whether insulin resistance could be contributing to symptoms or trends such as fatigue, increased hunger, difficulty losing weight, or increasing waist circumference. People also look at TyG when fasting glucose is “borderline” but they suspect their metabolism is shifting.
TyG can be especially useful if your triglycerides have been creeping up, your fasting glucose is rising, or you have a family history of type 2 diabetes or metabolic syndrome. It is also reasonable to check if you have physical signs that sometimes travel with insulin resistance, such as skin tags or darker patches of skin (acanthosis nigricans).
If you are already working on nutrition, activity, sleep, or weight management, TyG gives you another way to measure whether those changes are improving the underlying insulin-resistance pattern. Use it as part of clinician-directed care and risk assessment, not as a standalone self-diagnosis.
TyG Index is a calculated marker derived from your fasting triglycerides and fasting glucose; it supports risk assessment but does not diagnose insulin resistance or diabetes on its own.
Lab testing
Order labs to measure Triglycerides and Glucose
from $30.98 at Quest Diagnostics
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Get tested with Vitals Vault
With Vitals Vault, you can order labs that include the inputs needed to calculate TyG Index and then review your results in one place. This is helpful when you want a clear, repeatable way to track metabolic health without waiting for symptoms to become severe.
After your blood draw, you can use PocketMD to ask questions about what your TyG Index may suggest in the context of your triglycerides, glucose, and other cardiometabolic markers. That context matters, because the same TyG value can mean different things depending on your overall pattern.
If you plan to retest, try to keep conditions consistent—especially fasting status, alcohol intake, and recent exercise—so you can tell whether your trend reflects real improvement rather than day-to-day variability.
- Order labs and track trends in one place
- PocketMD support for plain-language interpretation
- Convenient testing through the Quest network
Key benefits of TyG Index testing
- Gives you a simple, accessible estimate of insulin resistance using common fasting labs.
- Helps identify an early cardiometabolic risk pattern that can precede type 2 diabetes.
- Adds context when fasting glucose alone looks “normal” but triglycerides are rising.
- Supports monitoring of lifestyle changes by tracking a single index over time.
- Pairs well with other metabolic markers to clarify whether elevated triglycerides are part of a broader pattern.
- Can help explain symptoms that often cluster with insulin resistance, such as fatigue and increased hunger.
- Makes it easier to have a focused conversation in PocketMD about next steps and retesting strategy.
What is TyG Index?
TyG Index stands for the Triglyceride-Glucose Index. It is a calculated marker that uses your fasting triglycerides (a blood fat) and fasting glucose (blood sugar) to estimate insulin resistance.
Insulin resistance means your cells do not respond to insulin as effectively, so your body has to produce more insulin to keep blood sugar in range. Over time, this pattern can contribute to higher triglycerides, rising glucose, metabolic syndrome, and increased cardiovascular risk.
TyG is often described as a “surrogate” marker because it correlates well with more complex research methods for measuring insulin resistance, including the hyperinsulinemic-euglycemic clamp. The clamp is considered a gold-standard test, but it is not practical for routine care. TyG is not perfect, but it is accessible and can be useful for trend tracking and risk stratification.
How TyG Index is calculated
Formula
ln(Triglycerides × Glucose) / 2
Labs calculate TyG Index from your fasting triglycerides and fasting glucose, typically using values reported in mg/dL. Because the calculation uses a natural logarithm (ln), the index compresses very high numbers and makes the result easier to compare across people and over time.
TyG is only as reliable as the inputs. If you were not truly fasting, if you had alcohol recently, or if triglycerides were temporarily elevated (for example after a very high-fat meal the day before), your TyG Index can look higher even if your baseline risk is lower.
What do my TyG Index results mean?
Low TyG Index
A lower TyG Index generally suggests better insulin sensitivity, meaning your fasting triglycerides and fasting glucose are both relatively low. This pattern is often seen when your liver is not overproducing triglycerides and your fasting glucose regulation is stable. Very low values are usually not a problem by themselves, but you still want to interpret them alongside your overall lipid panel, nutrition status, and any symptoms.
Optimal TyG Index
An “optimal” TyG Index is one that fits with a broader picture of metabolic health: triglycerides are controlled, fasting glucose is steady, and other markers on your panel do not suggest worsening insulin resistance. Because reference cutoffs can vary by lab and population, the most useful approach is often to compare your result to your prior results under similar fasting conditions. If your TyG Index is stable or improving over time, that is usually a reassuring signal that your insulin-resistance risk is not trending in the wrong direction.
High TyG Index
A higher TyG Index suggests a stronger insulin-resistance pattern, meaning fasting triglycerides and/or fasting glucose are elevated enough to push the index up. This can be seen with prediabetes, metabolic syndrome, higher carbohydrate intake that exceeds your current metabolic capacity, sedentary lifestyle, or excess visceral (abdominal) fat. A high TyG Index does not diagnose diabetes, but it can indicate higher risk for type 2 diabetes and cardiovascular disease, especially if it matches other findings like high triglycerides, low HDL, or increasing waist circumference.
Factors that influence TyG Index
TyG Index is sensitive to anything that changes fasting triglycerides or fasting glucose. Not fasting for 8–12 hours, drinking alcohol in the day or two before the test, recent intense exercise, acute illness, and major changes in diet can all shift the result. Certain medications can also affect glucose or triglycerides, which can move TyG even if your underlying insulin sensitivity has not changed. For the cleanest trend, retest under similar conditions and review the index alongside other metabolic markers rather than in isolation.
What's included
- Triglycerides
- Glucose
Frequently Asked Questions
What is a normal TyG Index range?
There is no single universal “normal” cutoff that applies to everyone, because studies and labs may use different populations and thresholds. In practice, your clinician often focuses on whether your TyG Index is relatively low and stable versus elevated and rising over time. The most useful comparison is your trend under consistent fasting conditions, interpreted alongside fasting glucose, triglycerides, HDL, waist circumference, and A1c.
Do I need to fast for a TyG Index test?
Yes, fasting is strongly recommended because TyG Index depends on fasting triglycerides and fasting glucose. A typical target is 8–12 hours of fasting with water only, unless your clinician gives different instructions. If you do not fast, triglycerides can rise significantly after meals and make your TyG Index look artificially high.
Is TyG Index better than HOMA-IR for insulin resistance?
They answer a similar question using different inputs. TyG Index uses fasting triglycerides and fasting glucose, while HOMA-IR uses fasting insulin and fasting glucose. TyG can be more accessible because triglycerides and glucose are commonly measured, and it correlates well with gold-standard clamp testing in many studies. HOMA-IR may add value when fasting insulin is available and reliable, so the best choice depends on what is on your panel and what you are trying to track.
Can TyG Index predict diabetes or heart disease?
A higher TyG Index is associated with higher risk of developing type 2 diabetes, metabolic syndrome, and cardiovascular disease in population studies. It is not a diagnosis and it cannot predict your future by itself, but it can flag a risk pattern earlier than glucose alone in some people. Your overall risk depends on many factors, including blood pressure, LDL-related markers, family history, body composition, and lifestyle.
What can raise my TyG Index even if I feel fine?
TyG Index can rise quietly when triglycerides increase, fasting glucose increases, or both. Common contributors include weight gain (especially abdominal), reduced activity, higher intake of refined carbohydrates or alcohol, poor sleep, and stress. Temporary factors like not fasting, recent alcohol, or acute illness can also elevate the result, which is why retesting under consistent conditions matters.
How often should I retest TyG Index?
If you are making lifestyle changes or monitoring a known metabolic risk pattern, many people retest every 8–12 weeks to see whether the trend is moving. If your results are stable and you are not actively changing anything, less frequent testing may be reasonable. Your best interval depends on your baseline risk, your goals, and whether your clinician is tracking related markers like A1c, lipids, and liver enzymes.