12 Biomarkers To Monitor if You Take a GLP-1 Medication

By InsideTracker, July 10, 2024

GLP1 Healthspan Blog

It’s rare for a medication to dominate headlines. But GLP-1 receptor agonists have done just that. 

Going by names like Ozempic, Wegovy, and Mounjaro, GLP-1s have captured the world’s imagination and redefined how we think about weight. 

If you’ve struggled with obesity, you may see these injections as the first ray of hope to come along in your lifetime. And you’re not alone. To date, one in eight adults have used GLP-1s, according to a recent KFF poll. [1]

The data is clear that these medications do a lot of good. But as with any drug, there are the effects you want, and the ones you don’t. Successful treatment often boils down to maximizing the benefit while reducing the cost.

To that end, there are several biomarkers you should be aware of. Biomarkers are molecules that circulate in your blood and tell the story of your health. They explain the inner workings of your heart, metabolism, muscles, gut, immune system, and more.

For people taking GLP-1s, biomarkers can reveal how well your medication is working and whether it’s having any undesirable effects. 

Whether you’re currently taking GLP-1s or considering them in your future, be sure to keep these biomarkers on your radar.




Biomarkers to monitor for GLP-1 safety

Experts consider GLP-1s safe. But that does not mean they’re risk-free. These are the markers to monitor for the best possible treatment.

Gut health markers

Measures of: Gastrointestinal health

Digestive problems such as nausea, diarrhea, and indigestion are among the most common GLP-1 side effects. 

There’s a simple explanation for this: A key feature of the medication is that it slows the speed at which food leaves your stomach. And food that lingers is more likely to cause trouble. (Learn more about how GLP-1 medications work.)

Slow-moving food can lead to an achy stomach or even vomiting. It can also increase the risk of pancreatitis, bowel obstruction, and gastroparesis (stomach paralysis). [2]

That’s why it’s smart to keep an eye on your gut health. At InsideTracker, we calculate your gut health score on a scale of 0 to 100 by measuring six biomarkers:

  • hsCRP (high-sensitivity C-reactive protein) 
  • HDL-cholesterol (high-density lipoprotein)
  • Cortisol
  • HbA1c (Hemoglobin A1c)
  • Glucose
  • Triglycerides

These markers are proxies for a healthy gut. By tracking them, you can ensure your gastrointestinal system stays strong during treatment.


Muscle mass and VO2max

Measures of: Strength and cardio fitness

Technically, these are physiomarkers—not blood biomarkers. But they’re important enough that we need to mention them.

Along with the rapid weight loss associated with GLP-1s, muscle mass and VO2max—two indicators of longevity—often decrease. [3] 

This occurs because you’re taking in fewer calories. As a result, your body may struggle to maintain tissues in your heart, muscle, liver, bone, and kidney.


Muscle mass indicates the total amount of muscle tissue in your body. This mass tends to decrease with age, and unfortunately, GLP-1s can expedite the process.

As muscle falls, your functional mobility also declines.
VO2max measures your body’s ability to use oxygen. It’s one of the most important markers of overall health, and at InsideTracker, we track it through your Garmin, Apple Watch, or other wearable tracker.

To minimize the damage to these markers, it’s smart to exercise for an hour every day. This duration has proven to be beneficial.

In a 2018 study, researchers found that 60 minutes of moderate to vigorous exercise each day (walking, jogging, cycling) helped preserve lean mass and VO2max during caloric restriction.

White blood cells

Measure of: Immune health

White blood cells are your immune system’s fighter cells, and in some cases, they may increase during GLP-1 treatment. 

If this happens, it’s likely due to an increase in heart rate. GLP-1s activate your autonomic nervous system, and that can cause your heart to beat faster. And a faster heart rate can increase your white blood cell count. 

In a study of people with diabetes, GLP-1s increased heart rate by about 3 beats per minute. [4] In most cases, this increase is nothing to worry about. (It’s notable that, in general, inflammation is more likely to fall during GLP-1 treatment.)

But to be safe, it’s worth watching your white blood cells. In addition to driving inflammation, a high count is linked with poor sleep. So you want to do what you can to keep this biomarker optimized.

Blood DNA Fitness tracking ebook

Biomarkers that should improve during GLP-1 treatment

The biomarker news isn't all bad. Some key health indicators are likely to improve on GLP-1s.

Monitoring this improvement allows you to verify your medication is having the intended effect, and watching your progress may even lead to better results.

When people see their efforts play out in data, they’re often motivated to double down on their healthy habits.


Measure of: Inflammation

Medication can have complicated, and sometimes contradictory, effects on the body. So while GLP-1s can have a negative effect on one inflammatory marker (white blood cells, listed above), they’re likely to have a positive effect on this one.

For background, CRP is a protein made by your liver. When you have high inflammation, your liver makes more.

A high-sensitivity C-reactive protein (hsCRP) test is a sensitive version of a CRP test. It’s used to detect small changes in your body’s inflammation. This is the test InsideTracker uses.

In general, you will likely see CRP and hsCRP fall while taking GLP-1s. This was found in a review of seven randomized studies. And the researchers noted that the improvement was better for patients who stayed on medication longer. [5]

With low hsCRP, you have less inflammation. That means you’re less likely to experience achiness, fatigue, or skin issues. You may also be less likely to become sick, and you’ll have a lower risk of heart disease and diabetes. 

The reduction in inflammation may be due in part to weight loss. It may also be a direct result of the medication. Researchers believe GLP-1s have an anti-inflammatory effect on tissues and immune cells. [6]

When you track your hsCRP, you should see your inflammation trending toward a healthy range. If that doesn’t happen, you can troubleshoot the problem with your doctor.

Glucose and HbA1c

Measures of: Metabolic health

Two common benefits of GLP-1 medications are the promotion of insulin release and the regulation of blood sugar. [7] 

You can see this benefit play out in two biomarkers: fasting glucose and HbA1c

Fasting glucose measures the sugar in your blood when you have not eaten anything for at least 8 hours. HbA1c looks at the average level of sugar in your blood for the previous 90 to 120 days. 

When these biomarkers are high, your risk for metabolic disorder and type 2 diabetes goes up. But GLP-1s should drive both numbers down—and the effect applies to both people with and without diabetes. [8]

Even better, GLP-1s demonstrate a “self-terminating” capacity to reduce blood sugar. This means that once they drive your glucose down to a fasting level, they stop. So they do not increase your risk of hypoglycemia, or low blood sugar. [9] 


LDL cholesterol, total cholesterol, triglycerides

Measures of: Heart health

Researchers have linked GLP-1 use to lower LDL-cholesterol, total cholesterol, and triglycerides. [10]

This is proving to be one of the biggest upsides to GLP-1 treatment. In one 2019 study, GLP-1 users with type 2 diabetes reduced their risk of stroke, heart attack, and other cardiovascular events by 12%. In addition, their risk of death by any cause also fell by 12%. [11]

Related: 6 Ways To Get the Most out of Your GLP-1 Medication

If your heart health biomarkers are out of range, GLP-1s can be lifesaving. Watching them fall into the optimal zone for health can be one of the most rewarding parts of treatment.


Measure of: Metabolic health

Alanine aminotransferase (ALT) is an enzyme found primarily in the liver. Its main function is to convert stored glucose into energy.

When your ALT levels are high, it signals poor metabolic health. It’s also a potential sign of non-alcoholic fatty liver disease (NAFLD), a condition that affects 70% of people with diabetes. [12] 

The most widely recommended treatment for NAFLD is weight loss (of 7% to 10% body weight). GLP-1 medications help with that, of course. But they also directly impact liver health.

Multiple studies have shown that GLP-1s can reduce ALT levels. The maximum impact occurs after about 30 weeks of treatment. [12]

How to track your biomarkers

The bottom line is that GLP-1s lead to widespread changes in your body. Tracking those changes from the inside can help you avoid problems and give you confidence that your treatment is working the way you want it to.

If you’re interested in testing, InsideTracker can simplify the process for you. We’ll schedule your first blood draw at a lab, or we can send a medical expert to your house.

We’ll present your blood report in easy–to-read graphs alongside personalized tips for driving your biomarkers back into range.

Screenshot - heart health

While the biomarkers listed in this article are the obvious ones to watch, we can also report on a wider array of health indicators. As your dietary and exercise patterns change, you may see shifting levels of vitamins (like vitamins D and B12), minerals (think iron and magnesium), hormones (testosterone, thyroid-stimulating hormone, etc), and more. 

With comprehensive blood testing, we can help catch problems early and ensure your treatment is having the effect you want. 

We can also combine your blood biomarkers with your DNA report and fitness tracker data to provide a deeply personalized plan for better health and complete GLP-1 success.

Just click to get started:



  1. https://www.kff.org/health-costs/press-release/poll-1-in-8-adults-say-theyve-taken-a-glp-1-drug-including-4-in-10-of-those-with-diabetes-and-1-in-4-of-those-with-heart-disease/
  2. https://jamanetwork.com/journals/jama/fullarticle/2810542
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5161655/
  4. https://academic.oup.com/eurheartj/article/39/suppl_1/ehy565.P2857/5080031
  5. https://pubmed.ncbi.nlm.nih.gov/28479155/
  6. https://pubmed.ncbi.nlm.nih.gov/29617641/
  7. https://pubmed.ncbi.nlm.nih.gov/29617641/
  8. https://pubmed.ncbi.nlm.nih.gov/25554560/
  9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4159612/
  10. https://pubmed.ncbi.nlm.nih.gov/25554560/
  11. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(19)30249-9/abstract
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9865319/

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