Prepared by: Research Desk
Prepared by: Research Desk. Sources are linked for verification.
Tesamorelin is a synthetic analogue of human growth hormone-releasing hormone (GHRH). It is one of the few peptides acting on the GHRH pathway with an FDA-approved product, and it has a published phase 3 trial record and several independent reviews. This entry follows the standard Peptide Infinity template described in What are peptides? Types, examples and a starter A–Z list: identity, mechanism, regulatory status, key evidence, safety notes and sources.
Status at a glance
Field | Entry |
|---|---|
Name | Tesamorelin (marketed as tesamorelin acetate) |
Class | GHRH analogue; acts at the GHRH receptor of the pituitary |
Length | 44 amino acids, with a modified N-terminus |
U.S. status | Approved: Egrifta, application 022505, listed in Drugs@FDA [1] |
Approved use | Reduction of excess abdominal fat in adults with HIV-associated lipodystrophy [1][6] |
First U.S. approval | 2010 [2][3] |
Status checked | 19 October 2026 |
"Approved" here refers to a specific product and a specific use. It does not mean the molecule is approved for any other purpose. The meaning of each badge is set out in Peptide FDA status explained.
Identity and structure
Native human GHRH is a 44-amino-acid peptide released by the hypothalamus. Tesamorelin keeps that full 44-residue sequence and adds a trans-3-hexenoyl group to the N-terminal tyrosine [2][3]. Unmodified GHRH is broken down quickly in the bloodstream, in large part by the enzyme dipeptidyl peptidase-4 (DPP-4), which cleaves near the N-terminus. Reviews describe the N-terminal modification as a design choice intended to make the molecule more resistant to that cleavage and to lengthen its activity compared with the native hormone [2][3][6].
This structure is the main point of difference from sermorelin, an older GHRH analogue that corresponds only to the first 29 amino acids of the native hormone. Both molecules keep the N-terminal region needed for receptor activation, but tesamorelin is the full-length sequence with a stabilising modification.
Mechanism of action
Tesamorelin binds to GHRH receptors on somatotroph cells in the anterior pituitary gland. Activation of these receptors stimulates the synthesis and release of the body's own growth hormone (GH). Circulating GH then raises insulin-like growth factor 1 (IGF-1), which is produced mainly in the liver [3][6].
Reviews emphasise that this is an upstream action. Recombinant GH supplies the hormone directly. Tesamorelin instead works through the pituitary, so GH is still released in pulses and remains subject to the normal feedback signals from somatostatin and IGF-1 [3][6][7]. GH has lipolytic (fat-mobilising) effects, particularly on visceral fat. That property is the reason the GHRH pathway was studied in conditions involving excess abdominal fat [6][7].
Background: HIV-associated lipodystrophy
HIV-associated lipodystrophy is a set of changes in body fat distribution described in people with HIV receiving antiretroviral therapy. One of its features is accumulation of visceral adipose tissue (VAT), the fat stored around abdominal organs. The reviews summarised here note that GH secretion has been reported to be lower in people with HIV who have excess visceral fat. This observation supplied part of the rationale for studying a GHRH analogue in this population [6][7].
Key studies
Phase 3 randomized trial (2007)
The pivotal trial published in the New England Journal of Medicine was a randomized, double-blind, placebo-controlled study in 412 adults with HIV and abdominal fat accumulation [4]. Over 26 weeks, VAT was measured by computed tomography. The investigators reported a decrease in VAT of about 15% in the tesamorelin group, compared with an increase of about 5% in the placebo group. They also reported changes in triglycerides and in the ratio of total to HDL cholesterol, and an increase in IGF-1 levels [4].
Analysis of VAT change and metabolic markers (2012)
A later analysis of phase 3 data in Clinical Infectious Diseases examined whether the size of the VAT change related to other metabolic measures. It reported that reduction in visceral adiposity was associated with a more favourable metabolic profile, including lipid- and glucose-related markers [5]. The analysis was designed to test an association. It does not show that one change caused the other.
Integrase inhibitor era (2024)
The original trials were run before integrase inhibitors became a standard component of antiretroviral therapy. A 2024 paper in AIDS examined efficacy and safety outcomes of tesamorelin in people with HIV on integrase inhibitors, a population of current interest because of the drug class's wide use [8].
Persistence of effect
Reviews of the phase 3 programme note that the VAT reductions seen during the trials were not sustained after tesamorelin was withdrawn. This finding is relevant to how the trial results are interpreted [3][6].
Evidence summary
Source | Study type | Population | What was measured or reported |
|---|---|---|---|
Falutz 2007 [4] | Randomized controlled trial (human) | 412 adults with HIV | VAT by CT, lipids, IGF-1 over 26 weeks |
Stanley 2012 [5] | Analysis of trial data (human) | Phase 3 participants | Association between VAT change and metabolic markers |
Russo 2024 [8] | Clinical analysis (human) | People with HIV on integrase inhibitors | Efficacy and safety outcomes |
Dhillon 2011; Spooner 2012; Grunfeld 2011 [2][3][6][7] | Narrative reviews | Not applicable | Structure, mechanism, trial summaries, safety |
Safety notes reported in the literature
The reviews summarise adverse events reported in the clinical trials. These include injection-site reactions, joint pain, muscle pain and peripheral oedema [3][6][7]. Because GH counteracts some of the actions of insulin, the reviews also discuss effects on glucose measures, and IGF-1 levels were tracked in the trials [3][6]. The product labelling linked from the Drugs@FDA record lists pregnancy and disruption of the hypothalamic–pituitary axis among its contraindications [1].
A drug monograph on tesamorelin indexed in PubMed summarises its pharmacology and adverse event profile, including what is known about hepatic safety [9]. Safety information on this page is a summary of published records. It is not a complete list and is not guidance on use.
Where tesamorelin sits in the wider peptide field
Tesamorelin often comes up alongside other molecules that act on the GH axis, many of which have no approved product. Recent reviews of peptide agents in aesthetic, metabolic and endocrine contexts [11], and in musculoskeletal and athletic-performance contexts [12], set approved agents beside unapproved ones. This contrast is the reason Peptide Infinity dates and sources every status badge. The related GHRH analogue sermorelin has its own Drugs@FDA record under application 019863 [10], with a different marketing history from tesamorelin's.
Further reading
Readers who want the physiology behind this entry in more depth often turn to a pharmacology or endocrinology textbook. These titles vary widely in depth and currency, and a few neutral criteria make them easier to compare.
Edition date: endocrine physiology and drug approvals change over time, and a recent edition is more likely to match current regulatory records.
Coverage of the hypothalamic–pituitary axis: dedicated chapters on growth hormone, IGF-1 and feedback control are more useful than a single summary page.
Referencing: chapters that cite primary literature allow claims to be checked against the original studies.
Authorship and publisher: academic presses and named subject editors signal a structured editing process.
Format and price transparency: print, ebook and rental prices differ, and a cheaper prior edition may or may not differ materially from the current one.
Specific titles are not named here, and the criteria above apply to any textbook listing. The About page explains how affiliate links are handled and how the site is funded.
Frequently asked questions
Is tesamorelin FDA approved?
Yes, for one specific use. Drugs@FDA lists tesamorelin acetate under application 022505 for reducing excess abdominal fat in adults with HIV-associated lipodystrophy [1]. That approval does not extend to any other purpose.
How does tesamorelin differ from sermorelin?
Both are GHRH analogues. Sermorelin corresponds to the first 29 amino acids of native GHRH, while tesamorelin is the full 44-residue sequence with a stabilising N-terminal modification [2][3]. The two also have separate regulatory records in Drugs@FDA [1][10].
Is tesamorelin the same as growth hormone?
No. Tesamorelin is a releasing-hormone analogue that prompts the pituitary to release the body's own GH, whereas recombinant GH is the hormone itself. Reviews note that this upstream action leaves pulsatile release and feedback regulation in place [3][6].
Last updated: 19 October 2026.
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