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Sermorelin vs. tesamorelin: how these two peptides differ
Published · Editorial team
Medical review pending · Last updated
Sermorelin and tesamorelin are often mentioned together because both act on the same hormone pathway. They differ in structure, FDA status, approved use, and how much evidence supports them. Here is how they compare.
Sermorelin vs. tesamorelin at a glance
| Sermorelin | Tesamorelin | |
|---|---|---|
| What it is | The first 29 amino acids of human GHRH | The full 44-amino-acid human GHRH sequence with a small chemical group added |
| FDA status | No FDA-approved product today; available only as a compounded drug | FDA-approved (Egrifta WR® and Egrifta SV®) |
| FDA-approved use | None current. Geref® was approved in 1997 for children with growth failure due to growth hormone deficiency and later discontinued. | Reducing excess abdominal fat in adults with HIV who have lipodystrophy |
| Not approved for | Anti-aging, muscle building, or general weight loss | |
| How it is given | Injection under the skin, at a dose set by the prescriber | Once-daily injection under the skin of the abdomen (Egrifta WR: 1.28 mg) |
| Quality oversight | Compounded drugs are not reviewed by FDA for safety, effectiveness, or quality | FDA-reviewed manufacturing and labeling |
The two Egrifta® formulations are not interchangeable. Follow the instructions for the product you are prescribed.
How they work
Your hypothalamus releases growth hormone-releasing hormone (GHRH), which tells the pituitary gland to release growth hormone in pulses. Growth hormone then raises levels of IGF-1, which acts on many tissues. Sermorelin and tesamorelin both mimic GHRH. Because they work through the pituitary instead of supplying growth hormone directly, the body's own feedback controls still apply.
Regulatory history
Sermorelin was sold as Geref®. The manufacturer stopped selling it in 2008 and its approval was later withdrawn. In 2013, FDA determined that Geref was not withdrawn from sale for reasons of safety or effectiveness. Today, licensed 503A pharmacies compound sermorelin for individual prescriptions, and compounded sermorelin is not FDA-approved.
Tesamorelin was first approved in 2010. Because an FDA-approved product is on the market, a prescriber would ordinarily use the approved product, and federal law restricts compounded copies of commercially available drugs. Learn more in are peptides legal in 2026?
What the evidence shows
Tesamorelin's approval is based on randomized, placebo-controlled trials in adults with HIV-associated lipodystrophy, where it reduced fat around the abdominal organs. Its label notes that it is not indicated for weight loss and that its long-term cardiovascular safety has not been established. Sermorelin's approved use was in children with growth hormone deficiency. Claims that either peptide slows aging or improves body composition in healthy adults have not been established by FDA.
Safety
Tesamorelin's label lists these warnings:
- Possible growth of existing tumors; it should not be used with active cancer
- Raised IGF-1 levels, which should be monitored
- Fluid retention, such as swelling, joint pain, or carpal tunnel symptoms
- Higher blood sugar and a risk of developing diabetes
- Allergic reactions, and a warning against use in people who are acutely critically ill
It should not be used in pregnancy or with disruption of the hypothalamic-pituitary axis. Common side effects include joint pain, injection-site redness and itching, pain in the arms or legs, swelling, and muscle pain.
Sermorelin has no current FDA label. Injection-site reactions, flushing, headache, and dizziness have been reported. Because it raises growth hormone, many of the same cautions apply, including use with active cancer, during pregnancy, or with diabetes. Long-term safety data in adults are limited.
Which one is right for you?
That depends on why you are considering it. A licensed clinician will review your history and labs, explain whether an FDA-approved option fits your situation, and decide whether either peptide is appropriate. See our sermorelin and tesamorelin pages for more detail.
Frequently asked questions
Is tesamorelin better than sermorelin?
They are approved and used for different things. Tesamorelin's FDA approval rests on trials in adults with HIV-associated lipodystrophy, and its benefit in other groups has not been established by FDA. No sermorelin product is FDA-approved today. A licensed clinician decides whether either fits you.
Can tesamorelin be prescribed for weight loss?
Tesamorelin is not FDA-approved for weight loss; its label says so directly. Any use outside the label is a decision a licensed clinician makes with you after weighing risks.
Is sermorelin a steroid or growth hormone?
Neither. Sermorelin is a peptide that signals the pituitary gland to release growth hormone. It is not an anabolic steroid and it is not growth hormone itself.
Do these peptides need lab monitoring?
Usually. Tesamorelin's label calls for monitoring IGF-1 and blood sugar. A clinician who prescribes either peptide typically checks labs before and during treatment.
Sources
- FDA-approved prescribing information: Egrifta WR (tesamorelin) (DailyMed, NLM)
- FDA-approved prescribing information: Egrifta SV (tesamorelin) (DailyMed, NLM)
- Federal Register: FDA determination that Geref (sermorelin acetate) was not withdrawn for safety or effectiveness (Mar 4, 2013)
- FDA: Bulk drug substances used in compounding (503A and 503B rules)
- FDA: Compounding and the FDA, questions and answers
Sources are listed for reference and do not imply endorsement. Regulatory status can change; check the date above.
This article is for education only and is not medical or legal advice. A licensed clinician decides whether any treatment is appropriate for you.