Records, not a recommendationThis comparison sets the FDA records and published trials side by side. It does not say which, if either, anyone should use; that is a question for a prescriber.
Sermorelin vs tesamorelin at a glance
Tesamorelin is the current, approved, better-studied product; sermorelin is a shorter molecule whose only approved product was discontinued.
| Sermorelin | Tesamorelin | |
|---|---|---|
| Structure | GHRH(1-29)-NH2, 29 amino acids, 3,357.9 g/mol[1] | GHRH(1-44) with a trans-3-hexenoyl group, 44 amino acids, 5,135.9 g/mol[2][11] |
| FDA status | Discontinued Geref approved 1990 and 1997; withdrawn 2009[7] | Approved Egrifta, first approved November 10, 2010[9] |
| Products today | None approved on the market | Egrifta SV and Egrifta WR (WR approved March 25, 2025)[10] |
| Approved use | Diagnosis, and treatment of GH deficiency in children with growth failure | Excess abdominal fat in adults with HIV and lipodystrophy; "not indicated for weight loss management"[11] |
| Dose on record | Trial dose 30 µg/kg daily in children (no label available)[15] | Label: 1.4 mg daily (SV) or 1.28 mg daily (WR)[11][12] |
| Main evidence | Open-label study in 110 children; two small studies in older men | Two phase 3 RCTs, 412 and 404 adults[13][14] |
| Compounding | 503B list: component of an approved drug[18] | Biological product since 2020; not eligible[4][5] |
| WADA 2026 | Prohibited, S2.2.4 | Prohibited, S2.2.4[22] |
Structure: a fragment vs the whole hormone
Sermorelin is the first 29 amino acids of human GHRH; tesamorelin is all 44, with a chemical group added to the first amino acid.[1][2] That difference has a legal consequence. U.S. law counts any chain longer than 40 amino acids as a protein,[3] so Egrifta was moved to a biologics license in 2020,[4] and biologics cannot be compounded.[5] Sermorelin, at 29, stays on the peptide side.
Approval history
Tesamorelin's approval is current; sermorelin's ended at the company's request, not for safety reasons.
| Date | Sermorelin | Tesamorelin |
|---|---|---|
| 1990 | Geref approved as a diagnostic[6] | — |
| 1997 | Geref approved to treat GH deficiency in children | — |
| 2008–2009 | Geref discontinued; approvals withdrawn June 18, 2009[7] | — |
| 2010 | — | Egrifta approved November 10[9] |
| 2013 | FDA: Geref not withdrawn for safety or effectiveness[8] | — |
| 2020 | — | Transferred to a biologics license[4] |
| 2025 | — | Egrifta WR approved March 25[10] |
Evidence: what each was tested for
Tesamorelin has randomized, placebo-controlled evidence in adults; sermorelin's evidence is an open-label pediatric study and two small adult studies.
- Tesamorelin: in a 412-adult phase 3 trial, visceral abdominal fat fell 15.2% against a 5.0% rise on placebo over 26 weeks; a pooled analysis of 806 adults found a 15.4% treatment effect.[13][14] The label notes body weight did not differ from placebo.[11]
- Sermorelin: in 110 children with GH deficiency, growth rate rose from 4.1 to 8.0 cm a year at 6 months.[15] Small studies in older men found raised growth hormone with mixed IGF-I and strength results.[16][17]
Because the two were tested in different people for different outcomes, the results cannot be compared directly.
Side effects
Tesamorelin's side effects are listed on its label; sermorelin's come only from small studies that called it well tolerated.
- Tesamorelin (label, over 5%): joint pain, injection-site redness and itching, pain in the arms or legs, swelling (peripheral edema) and muscle pain. Contraindications include a disrupted hypothalamic-pituitary axis, active cancer, hypersensitivity and pregnancy.[11]
- Sermorelin (studies): "well tolerated" in children, no effect on glucose or blood pressure in older men, and no significant adverse effects in a 6-week study.[15][16][17] The Geref label is not available from the FDA.[6]
Research-use versions
Both molecules are sold online as "research" peptides, and the FDA has warned sellers of both. A December 2024 letter covered research-use sermorelin;[19] August 2026 letters covered research-use tesamorelin, including blends with ipamorelin.[20][21] Those products are not Geref or Egrifta. See are peptides safe?
Which is better?
No study answers that: there is no head-to-head trial, and the two were approved for unrelated conditions. What the records do show is that only tesamorelin has a current FDA approval, for one specific use. More on each: sermorelin, the tesamorelin calculator, and how both compare with ipamorelin on the HGH peptides page.
Frequently asked questions
What is the difference between sermorelin and tesamorelin?
Is tesamorelin stronger than sermorelin?
No trial has compared them, so there is no evidence either way. They were approved for different conditions and studied in different people.
Are sermorelin and tesamorelin banned in sport?
Yes. The WADA 2026 Prohibited List names both under S2.2.4 as GHRH analogues, prohibited at all times.[22]
Is tesamorelin approved for weight loss?
No. The Egrifta label says it is "not indicated for weight loss management".[11]
Sources
- PubChem CID 16132413: sermorelin
- PubChem CID 16137828: tesamorelin
- Final rule: Definition of the term "biological product" (85 FR 10057)
- List of approved NDAs for biological products that were deemed to be BLAs on March 23, 2020
- Notice to compounders: changes that affect compounding as of March 23, 2020
- Drugs@FDA: Geref (sermorelin acetate), NDA 020443
- Withdrawal of approval of 92 new drug applications, including Geref (74 FR 23407)
- Determination that Geref (sermorelin acetate) injection was not withdrawn from sale for reasons of safety or effectiveness (78 FR 14095)
- Drugs@FDA: Egrifta (tesamorelin), BLA 022505
- Approval letter, BLA 022505/S-020 (Egrifta WR)
- Egrifta SV (tesamorelin) prescribing information
- Egrifta WR (tesamorelin) prescribing information
- Falutz J et al. Tesamorelin phase 3 trial in HIV-infected patients with abdominal fat accumulation (NEJM 2007;357:2359–70)
- Falutz J et al. Pooled analysis of two phase 3 tesamorelin trials (JCEM 2010;95:4291–304)
- Thorner M et al. Sermorelin in prepubertal children with growth hormone deficiency (JCEM 1996;81:1189–96)
- Corpas E et al. GHRH(1-29) twice daily in older men (JCEM 1992;75:530–5)
- Vittone J et al. Nightly GHRH(1-29) in healthy older men (Metabolism 1997;46:89–96)
- Bulk drug substances nominated for use in compounding under section 503B (category lists)
- Warning letter: Xcel Research LLC
- Warning letter: Royal Peptides LLC
- Warning letter: NuScience Peptides LLC
- World Anti-Doping Code: Prohibited List 2026