Sermorelin vs Tesamorelin: Two GHRH Analogs Compared (2026)

Sermorelin and tesamorelin are both analogs of growth hormone–releasing hormone (GHRH), but their regulatory histories are opposite. Tesamorelin is a currently FDA-approved drug (Egrifta) indicated to reduce excess abdominal fat in adults with HIV-associated lipodystrophy. Sermorelin was once approved as Geref; the product left the market, and FDA later determined that it was not withdrawn for reasons of safety or effectiveness. Tesamorelin has phase 3 trial data; sermorelin's evidence is older and smaller.

Educational content for licensed healthcare professionals. Not medical advice; dosing and treatment decisions belong to the prescribing clinician.

Sermorelin vs Tesamorelin at a Glance

Same Hormone, Different Engineering

Both drugs mimic GHRH, the hypothalamic peptide that tells pituitary somatotrophs to release growth hormone. Because they work upstream of GH, the GH they produce is still subject to the body's somatostatin brake and IGF-1 feedback — the main conceptual difference from injecting GH itself (see HGH vs peptides).

Sermorelin is the shortest fully active fragment of GHRH, the first 29 amino acids with a C-terminal amide. It is rapidly cleared, so its effect is brief.

Tesamorelin keeps all 44 amino acids of human GHRH and adds a trans-3-hexenoyl group to the N-terminus, protecting it from the enzyme that inactivates native GHRH. That modification is what made an approved product practical.

Sermorelin: The Geref Story

Sermorelin acetate was marketed as Geref under two new drug applications held by EMD Serono, first approved in December 1990 and September 1997, according to the Federal Register. A 1999 review summarized its use as a diagnostic test of pituitary GH secretion and in treating prepubertal children with idiopathic GH deficiency, where it produced sustained increases in height velocity; it had not been compared directly with somatropin [1].

EMD Serono requested withdrawal of both applications in 2008. On March 4, 2013, FDA published a determination that Geref (sermorelin acetate) injection was not withdrawn from sale for reasons of safety or effectiveness. That finding allows FDA to approve generic applications referencing Geref, and it is the reason sermorelin is often described as "previously approved" rather than "never approved."

Adult evidence is thin. In a small study at Johns Hopkins, 11 healthy men aged 64–76 with low IGF-1 received GHRH(1–29) for six weeks. Nocturnal GH release rose, but IGF-1 did not change; two of six strength measures and one endurance test improved, while body composition by DEXA, glucose and lipids were unchanged [2]. A commentary in Clinical Interventions in Aging argued for sermorelin as an alternative to GH in adult-onset GH insufficiency, but it was an opinion piece, not trial data [3].

Tesamorelin: The Approved GHRH Analog

Tesamorelin was approved by FDA on November 10, 2010, as Egrifta. The current Egrifta WR label states it is "indicated for the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy," with limitations of use noting that long-term cardiovascular safety has not been established and that it is not indicated for weight-loss management (DailyMed).

The approval rested on randomized phase 3 trials. In the first, published in the New England Journal of Medicine, visceral adipose tissue fell 15.2% over 26 weeks with tesamorelin versus a 5.0% increase with placebo; triglycerides and the total-to-HDL cholesterol ratio improved and IGF-1 rose 81% [4]. A pooled analysis of the two phase 3 trials with safety-extension data confirmed the visceral-fat effect [5]. Later, an NIH-funded randomized trial in 61 people with HIV and nonalcoholic fatty liver disease found a greater reduction in hepatic fat fraction with tesamorelin than placebo over 12 months, without differences in glucose or HbA1c [6].

For how tesamorelin compares with an unapproved, long-acting GHRH analog, see CJC-1295 vs tesamorelin for visceral fat.

Safety Considerations

Tesamorelin has a full U.S. label. Its contraindications are disruption of the hypothalamic-pituitary axis, active malignancy, known hypersensitivity, and pregnancy; warnings and precautions cover increased risk of neoplasms, elevated IGF-1, fluid retention, glucose intolerance or diabetes, hypersensitivity reactions, and increased mortality in acute critical illness (DailyMed label above). In the NEJM trial adverse events did not differ significantly from placebo overall, but more tesamorelin patients withdrew because of an adverse event [4].

Sermorelin has no current U.S. label, so there is no FDA-reviewed contraindication list for today's compounded preparations. The same physiological cautions apply to any therapy that raises GH and IGF-1 — active cancer, uncontrolled diabetes, and pregnancy among them. For sermorelin-specific adverse effects, see sermorelin side effects.

Dosing belongs to the prescriber; this article does not cover it.

2026 Regulatory Status

• Tesamorelin is an FDA-approved prescription drug. Using an approved product for its labeled indication is the clearest regulatory position of any GH peptide; off-label use is a clinical judgment for the prescriber.
• Sermorelin has no currently marketed FDA-approved product. Because sermorelin acetate was a component of an approved drug that FDA found was not withdrawn for safety or effectiveness reasons, it sits in a different position from never-approved peptides; it does not appear in FDA's 503A nomination categories list (updated May 14, 2026). Confirm current compounding status on the FDA Peptide Status Tracker and with the dispensing pharmacy.

Both are prohibited at all times for tested athletes under the WADA Prohibited List as GHRH analogues.

Which Is Used When?

The difference is less about pharmacology than about evidence and label. Tesamorelin is the GHRH analog with randomized phase 3 data and an approved indication; outside HIV lipodystrophy it is off-label. Sermorelin is the older, shorter fragment with historic pediatric approval and limited adult data. Neither is a substitute for diagnosing true adult GH deficiency, which our signs you need growth hormone therapy article covers. For sermorelin alongside a ghrelin mimetic, see sermorelin vs ipamorelin.

Newtropin does not prescribe, compound, or dispense. We connect licensed providers with licensed 503A partner pharmacies that together cover all 50 states and D.C.; prescribers can start at For Providers.

Frequently Asked Questions

What is the difference between sermorelin and tesamorelin?

Both are GHRH analogs that stimulate the pituitary to release growth hormone. Sermorelin is the 29-amino-acid active fragment of GHRH; tesamorelin is full-length 44-amino-acid GHRH with a stabilizing modification. Tesamorelin is FDA-approved; sermorelin's approved product is no longer marketed.

Is tesamorelin FDA approved?

Yes. Tesamorelin (Egrifta) was approved in November 2010 to reduce excess abdominal fat in HIV-infected adults with lipodystrophy. The label states it is not indicated for weight-loss management.

Why was sermorelin (Geref) discontinued?

EMD Serono requested withdrawal of the Geref applications in 2008, and in 2013 FDA determined that it was not withdrawn from sale for reasons of safety or effectiveness. FDA's notice did not attribute the discontinuation to a safety problem.

Is tesamorelin better than sermorelin for belly fat?

Tesamorelin has randomized phase 3 evidence for reducing visceral fat in HIV-associated lipodystrophy; sermorelin does not have comparable trials. The two have not been compared head to head, and tesamorelin's data do not establish an effect outside its studied population.

Is sermorelin legal to prescribe?

There is no FDA-approved sermorelin product on the market, so sermorelin is available only through compounding. Its compounding status differs from never-approved peptides because it was a component of an approved drug; check the FDA Peptide Status Tracker and the dispensing pharmacy.

Are sermorelin and tesamorelin banned in sports?

Yes. WADA lists sermorelin and tesamorelin as prohibited GHRH analogues under S2, banned at all times.

References

1. Prakash A, et al. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs. 1999;12(2):139-57. PubMed
2. Vittone J, et al. Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men. Metabolism. 1997;46(1):89-96. PubMed
3. Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging. 2006;1(4):307-8. PubMed
4. Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-70. PubMed
5. Falutz J, et al. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. J Clin Endocrinol Metab. 2010;95(9):4291-304. PubMed
6. Stanley TL, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. Lancet HIV. 2019;6(12):e821-e830. PubMed