Growth Hormone Peptide Research

Tesamorelin vs Sermorelin: Research Data

How the two GHRH analogs differ in structure, approval history and human evidence, what side effects trials reported, and where ipamorelin fits.

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Fact-checked · Reviewed by Remy Research Editorial Board
Update History ▾
October 27, 2026: Initial publication, built from the March 2025 EGRIFTA WR label, Drugs@FDA, the 2013 Federal Register Geref determination, FDA’s Category 2 page, the WADA 2027 List and primary trial papers.
Research-use-only framing applied throughout in line with Remy editorial standards.
TL;DR — Research Summary

Tesamorelin vs sermorelin is a comparison between two growth hormone releasing hormone (GHRH) analogs that act on the same GHRH receptor but have very different evidence behind them. Tesamorelin is the full 44-amino-acid GHRH sequence with a stabilising group at the N terminus, and it is FDA approved (as Egrifta) for one use: reducing excess abdominal fat in HIV-infected adults with lipodystrophy.[1][2] Sermorelin is the first 29 amino acids of GHRH; it was approved as Geref for growth hormone deficiency in children and later left the market, and FDA determined that it was not withdrawn for reasons of safety or effectiveness.[3][4]

Tesamorelin has two large phase 3 trials and a body of follow-on work on visceral fat and liver fat. Sermorelin’s human data are mostly older pediatric growth studies and small trials in older men. No trial has compared the two compounds directly. Remy Research supplies tesamorelin for in-vitro laboratory research only, not for human or veterinary use.

Compliance note: this page is a research review, not a treatment guide. It does not provide human-use dosing, therapeutic recommendations, or any clinical-use instructions, and should be read in the same non-therapeutic frame required across Remy's research content.

Tesamorelin vs Sermorelin: The Key Differences

Both compounds are growth hormone peptides that mimic endogenous GHRH (growth hormone releasing hormone), the hypothalamic signal that tells the anterior pituitary to make and release growth hormone. The two peptides differ in length, in stability and in what regulators and clinical studies have said about them.

Tesamorelin vs Sermorelin — Side-by-Side
Property Tesamorelin Sermorelin
Structure GHRH(1-44) with an N-terminal hexenoyl group GHRH(1-29), the shortest fully active fragment
Molecular weight 5,135.9 Da (free base) 3,357.9 g/mol
Receptor GHRH receptor GHRH receptor
FDA status Approved 2010 (Egrifta) Approved as Geref; discontinued
Approved use Excess abdominal fat in HIV lipodystrophy Pediatric GH deficiency; pituitary GH test
Largest trials Two phase 3 RCTs (412 and 404 patients) Open-label study in 110 children
WADA 2027 Named under S2.2.4 Named under S2.2.4

Sources: tesamorelin structure, molecular weight and approval from the FDA label and Drugs@FDA;[1][2] sermorelin structure and molecular weight from a drug review and PubChem;[3][5] Geref indications from the Federal Register;[4] trial sizes from the primary papers;[6][7][8] sport status from the WADA List.[9]

How Both Tesamorelin and Sermorelin Act on the GHRH Receptor

GHRH acts on somatotroph cells of the pituitary gland to stimulate the synthesis and pulsatile release of endogenous growth hormone. Growth hormone then acts on liver, muscle, bone and fat cells, and many of its effects run through insulin like growth factor 1 (IGF-1) made in the liver.[1] Both analogs use this route: they do not supply growth hormone themselves but act through the pituitary’s own release.

Tesamorelin binds human GHRH receptors in vitro with potency similar to native GHRH.[1] Its N-terminal hexenoyl group (a six-carbon chain attached to the first tyrosine) was added to the complete 44-amino-acid sequence; the label still reports a short half life, about 11 minutes in healthy subjects.[1] In 13 healthy men, two weeks of tesamorelin raised mean overnight growth hormone, peak area and basal secretion and increased IGF-1, while fasting glucose and insulin-stimulated glucose uptake did not change.[10] In HIV trials, other pituitary hormones (TSH, LH, ACTH and prolactin) showed no clinically significant change.[1]

Sermorelin corresponds to residues 1 to 29 of human GHRH and is described as the shortest synthetic peptide with the full biological activity of GHRH. Given intravenously, it stimulates growth hormone secretion from the anterior pituitary specifically, which is why it was used as a diagnostic test.[3]

Tesamorelin: Visceral Fat and Body Composition Evidence

Tesamorelin’s evidence comes from people with HIV who had abdominal fat accumulation on antiretroviral therapy. In the first phase 3 trial (412 patients, 26 weeks, double-blind, placebo-controlled), the primary endpoint was visceral adipose tissue on CT: it fell 15.2% with tesamorelin and rose 5.0% with placebo, triglycerides fell and IGF-1 rose 81%.[6] The second phase 3 trial (404 patients) reported a 10.9% fall in visceral fat against 0.6% with placebo after six months, with no change in limb or abdominal subcutaneous fat; the gains were rapidly lost in patients switched to placebo.[7] A pooled analysis of both trials (806 patients) put the treatment effect at −15.4% for visceral adipose tissue, with VAT reduction maintained to week 52 in those who continued.[11]

Liver fat is the second main finding. In a 12-month randomised trial in 61 people with HIV and non-alcoholic fatty liver disease, tesamorelin produced a 37% relative reduction in hepatic fat fraction compared with placebo.[12] A 2026 meta-analysis of five randomised trials in HIV-infected patients found less visceral fat, limb fat, hepatic fat and waist circumference, and about 1.4 kg more lean mass, with no significant change in body mass index or subcutaneous fat.[13]

Two limits matter. The FDA label states that tesamorelin is not indicated for weight loss management because it has a weight-neutral effect, and that its long-term cardiovascular safety has not been established.[1] The fat loss seen in trials was visceral fat in HIV-associated lipodystrophy, not general body fat or obesity, so tesamorelin is not a weight management drug.

Sermorelin: Growth Evidence and Anti Aging Claims

Sermorelin’s main clinical evidence is in children with growth hormone deficiency. In an open-label multicentre study of 110 previously untreated prepubertal children, mean height velocity rose from 4.1 cm per year to 8.0 cm per year at six months and 7.2 cm per year at twelve months; 74% were good responders at six months, and no adverse changes in biochemical or hormonal tests were seen.[8] A review of the pediatric data found that height velocity gains were smaller than with growth hormone itself.[3]

Adult data are small. In ten healthy older men, two weeks of GHRH(1-29) restored growth hormone and IGF-1 to the levels seen in young men without affecting fasting glucose or blood pressure.[14] In eleven men aged 64 to 76, six weeks of GHRH(1-29) increased nocturnal growth hormone and improved two of six strength measures, but did not change IGF-1, body composition, muscle or fat on DEXA, or glucose.[15] No sermorelin trial has measured visceral fat as a primary endpoint, so anti aging, fat loss and sleep quality claims for sermorelin rest on these small endocrine studies rather than outcome trials.

Which Has More Human Evidence?

Tesamorelin, clearly. It has two randomised phase 3 trials with a combined 806 patients, a primary endpoint measured by CT, long-term safety extensions, a liver fat trial and recent meta-analyses.[11][12][13] Sermorelin’s clinical literature is older and smaller, with the largest study open-label and in children.[8][3] The two compounds have never been tested against each other, so any claim that one “works better” for the same goal is a cross-trial inference.

Tesamorelin and Sermorelin Side Effects Compared

In the pooled 26-week placebo-controlled phase in the tesamorelin label, these adverse effects were more common than with placebo:[1]

The label contraindicates tesamorelin in people with a disrupted hypothalamic-pituitary axis, active malignancy or hypersensitivity to it.[1] For sermorelin, the review of clinical use reported transient facial flushing and injection site pain as the most common adverse events, and described it as well tolerated.[3] The two safety profiles come from very different populations and exposure lengths, so they are not directly comparable.

Is Tesamorelin or Sermorelin FDA Approved?

Where both stand as of October 27, 2026.
  • Tesamorelin. FDA approved on November 10, 2010 as Egrifta (now BLA 022505); the current Egrifta WR formulation was approved on March 25, 2025. Its only indication is reducing excess abdominal fat in HIV-infected adults with lipodystrophy.[2][1]
  • Sermorelin. Geref was approved for idiopathic growth hormone deficiency in children with growth failure and, in a separate form, for testing the pituitary’s ability to secrete growth hormone. Both products were discontinued, and in 2013 FDA determined that they were not withdrawn for reasons of safety or effectiveness.[4]
  • Compounding. Neither tesamorelin nor sermorelin appears on FDA’s Category 2 list of bulk substances that may present significant safety risks.[16]
  • Sport. WADA’s 2027 List names both under S2.2.4 (GHRH and its analogues), prohibited at all times.[9]
  • UAE. Remy Research supplies research grade tesamorelin for in-vitro laboratory research only, not for human or veterinary use. Research grade material is not Egrifta.

Where Ipamorelin Fits: Tesamorelin vs Ipamorelin

Ipamorelin is often named alongside the two, but it is not a GHRH analog. It is a five-amino-acid growth hormone secretagogue that acts through the ghrelin receptor (GHS-R1a). In its first pharmacology paper it released growth hormone without raising ACTH or cortisol above GHRH-like levels in swine, and without changing prolactin, FSH, LH or TSH.[17] In healthy volunteers it produced a single growth hormone pulse and had a terminal half life of about 2 hours.[18]

Its human efficacy record is one published phase 2 trial in 114 patients after bowel surgery, which found no significant benefit over placebo on recovery of gut function.[19] FDA lists ipamorelin acetate in 503B Category 2, citing immunogenicity and impurity risks and serious adverse events, including death, that it links to that intravenous study.[16] WADA names it as a growth hormone secretagogue under S2.2.4.[9] So on approval and trial depth, tesamorelin is far ahead. For the full profile see ipamorelin benefits and side effects, and for the paired GHRH plus ghrelin-receptor approach see CJC-1295 + ipamorelin benefits and side effects.

What the Research Does Not Yet Show

Tesamorelin for Laboratory Research

Remy Research supplies research grade tesamorelin, intended for in-vitro research use only, as the Tesamorelin 10mg vial, the Tesamorelin 20mg pen and the Genovare Tesamorelin 25mg AQ pen, and in the three-peptide Genovare Super Geno I 36mg AQ pen with CJC-1295 (no DAC) and ipamorelin. Each product page carries its batch testing details. Sermorelin is not among our research peptides. For the full tesamorelin trial record, read the tesamorelin GHRH analog research review, and for all four GH-axis peptides side by side see the GHRH peptides comparison.

Our Research Standards

This article prioritizes primary literature, FDA labels and regulator records, and keeps pediatric, older-adult and HIV trial evidence apart. Cross-trial comparisons are labelled as such. No therapeutic, dosing or administration guidance is given. Read our editorial policy →

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Editorial Board, Remy Research

The Remy Research Editorial Board reviews Remy's peptide research library, with a focus on analytical verification, clinical-trial interpretation, and compliance-safe scientific communication.

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Tesamorelin vs Sermorelin FAQ

Which is better, tesamorelin or sermorelin?

Neither has been tested against the other. Tesamorelin has much stronger human evidence: two phase 3 trials and FDA approval for abdominal fat in HIV lipodystrophy. Sermorelin’s evidence is older, smaller and mostly pediatric.[11][2][8]

What is the difference between tesamorelin and sermorelin?

Tesamorelin is the full 44-amino-acid GHRH with a stabilising hexenoyl group; sermorelin is the 29-amino-acid active fragment. Both act on the GHRH receptor.[1][3]

Is tesamorelin FDA approved?

Yes, for one indication: reducing excess abdominal fat in HIV-infected adults with lipodystrophy. It is not indicated for weight loss management.[1][2]

Is sermorelin FDA approved?

It was, as Geref, for growth hormone deficiency in children and as a pituitary test. Geref was discontinued, and FDA determined in 2013 that it was not withdrawn for safety or effectiveness reasons.[4]

What are the side effects of tesamorelin?

In trials, injection site reactions, joint pain, muscle pain, peripheral edema and tingling were more common than with placebo; the label also warns about glucose intolerance, high IGF-1 and hypersensitivity.[1]

What are the side effects of sermorelin?

Transient facial flushing and injection site pain were the most commonly reported adverse events in clinical use.[3]

Is tesamorelin safe?

Its safety was studied in HIV patients for up to 52 weeks, and the label lists specific risks and contraindications. Long-term cardiovascular safety has not been established.[1][11]

Does sermorelin get rid of visceral fat?

No trial has shown that. In older men, six weeks of GHRH(1-29) did not change fat or muscle measured by DEXA.[15]

Which is stronger, tesamorelin or ipamorelin?

They act on different receptors and have not been compared directly. Tesamorelin has phase 3 evidence and FDA approval; ipamorelin’s only published efficacy trial was negative.[1][19]

Sources

  1. U.S. Food and Drug Administration. EGRIFTA WR (tesamorelin for injection) prescribing information, BLA 022505 supplement 20, approved March 25, 2025 (indications and limitations of use, warnings, Table 1 adverse reactions, description, clinical pharmacology). accessdata.fda.gov ↩
  2. U.S. Food and Drug Administration. Drugs@FDA: BLA 022505 (EGRIFTA, tesamorelin acetate; Theratechnologies): original approval November 10, 2010; former NDA deemed a BLA on March 23, 2020; supplement 20 approved March 25, 2025. accessdata.fda.gov ↩
  3. Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs. 1999;12(2):139-157. doi: 10.2165/00063030-199912020-00007 · PMID: 18031173 ↩
  4. U.S. Food and Drug Administration. Determination That GEREF (Sermorelin Acetate) Injection products Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness (title shortened). Federal Register 78 FR 14095, March 4, 2013 (Docket FDA-2012-P-1071). federalregister.gov ↩
  5. National Center for Biotechnology Information. PubChem Compound Summary for CID 16132413, Sermorelin (C149H246N44O42S; molecular weight 3357.9). pubchem.ncbi.nlm.nih.gov/compound/16132413 ↩
  6. Falutz J, Allas S, Blot K, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-2370. doi: 10.1056/NEJMoa072375 · PMID: 18057338 ↩
  7. Falutz J, Potvin D, Mamputu JC, et al. Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with a safety extension. J Acquir Immune Defic Syndr. 2010;53(3):311-322. doi: 10.1097/QAI.0b013e3181cbdaff · PMID: 20101189 ↩
  8. Thorner M, Rochiccioli P, Colle M, et al; Geref International Study Group. Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. J Clin Endocrinol Metab. 1996;81(3):1189-1196. doi: 10.1210/jcem.81.3.8772599 · PMID: 8772599 ↩
  9. World Anti-Doping Agency. 2027 Prohibited List (in force January 1, 2027), S2.2.4 Growth hormone releasing factors: GHRH and its analogues (e.g. CJC-1295, sermorelin and tesamorelin); growth hormone secretagogues (e.g. ipamorelin); prohibited at all times. wada-ama.org ↩
  10. Stanley TL, Chen CY, Branch KL, Makimura H, Grinspoon SK. Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men. J Clin Endocrinol Metab. 2011;96(1):150-158. doi: 10.1210/jc.2010-1587 · PMID: 20943777 ↩
  11. Falutz J, Mamputu JC, Potvin D, 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):4291-4304. doi: 10.1210/jc.2010-0490 · PMID: 20554713 ↩
  12. Stanley TL, Fourman LT, Feldpausch MN, 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. doi: 10.1016/S2352-3018(19)30338-8 · PMID: 31611038 ↩
  13. Badran AS, Helal A, Shata KS, Ayesh H. Body composition, hepatic fat, metabolic, and safety outcomes of Tesamorelin, a GHRH analogue, in HIV-associated lipodystrophy: A meta-analysis of randomized controlled trials. Obes Res Clin Pract. 2026;20(1):2-12. doi: 10.1016/j.orcp.2026.01.002 · PMID: 41545261 ↩
  14. Corpas E, Harman SM, Piñeyro MA, Roberson R, Blackman MR. Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men. J Clin Endocrinol Metab. 1992;75(2):530-535. doi: 10.1210/jcem.75.2.1379256 · PMID: 1379256 ↩
  15. Vittone J, Blackman MR, Busby-Whitehead 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. doi: 10.1016/s0026-0495(97)90174-8 · PMID: 9005976 ↩
  16. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (Category 2, including “Bulk drug substances nominated but withdrawn”). Content current as of April 22, 2026. fda.gov ↩
  17. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. doi: 10.1530/eje.0.1390552 · PMID: 9849822 ↩
  18. Gobburu JV, Agersø H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412-1416. doi: 10.1023/a:1018955126402 · PMID: 10496658 ↩
  19. Beck DE, Sweeney WB, McCarter MD; Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014;29(12):1527-1534. doi: 10.1007/s00384-014-2030-8 · PMID: 25331030 ↩

For catalog details, see the Tesamorelin 10mg vial, the Tesamorelin 20mg pen, the Genovare Tesamorelin 25mg AQ pen and the Genovare Super Geno I 36mg AQ pen. For editorial standards, continue to the editorial policy.

Related Research

Catalog Tesamorelin 10mg Vial→ Catalog Genovare Tesamorelin 25mg AQ Pen→ Research Tesamorelin GHRH Analog Research→ Comparison GHRH Peptides Compared→ GH Secretagogue Ipamorelin Benefits & Side Effects→ GH Secretagogue CJC-1295 + Ipamorelin Benefits & Side Effects→ Regulation FDA Peptides 2026→ Catalog Research Peptide Catalog→