Tesamorelin Peptide: Pharmacology and Regulatory Status

Research summary. Tesamorelin is a synthetic analog of human growth hormone-releasing factor (GRF/GHRH), structurally the 44-residue human GRF sequence with a hexenoyl group attached at the N-terminal tyrosine. Published pharmacology describes it as a GRF receptor agonist that raises endogenous growth hormone and, downstream, IGF-1. Its regulatory position is unusual and worth stating precisely: it is the active ingredient of an FDA-licensed biologic, not an unapproved compound. As stocked by Nox Amino it is a reference material characterized by identity and purity.

Author: Nox Amino Research Team Reviewed by: the Nox Amino Research Team Published: July 16, 2026 · Updated: July 16, 2026 Editorial methodology: /learn/editorial-standards

Research Use Only (RUO). All materials referenced on this page are intended exclusively for laboratory research and analytical use. They are not drugs, dietary supplements, or articles for human or veterinary consumption, and nothing here constitutes medical advice or a recommendation for use in or on the body. This page describes receptor pharmacology and regulatory records only. It contains no dosing, preparation, or administration information, and it makes no claim about outcomes for any reader. Statements about approved products describe those products, not any research material. See our Certificates of Analysis for identity and purity data.

What tesamorelin is, per FDA's own records

FDA's approved labeling describes the molecule directly: "Tesamorelin is a human growth hormone-releasing factor (GRF) analog produced synthetically. It is comprised of the 44 amino acid sequence of human GRF and a hexenoyl moiety, a C6 chain with a double bond at position 3, attached to the tyrosine residue at the N-terminal part of the molecule" (EGRIFTA WR label, FDA 2025).

The analytical identity, drawn from FDA's own pharmacology review and labeling:

Attribute	Value	Source
Chemical name	N-(trans-3-hexenoyl)-human growth hormone releasing factor (1-44) acetate	FDA Pharmacology Review, NDA 22-505
CAS number	218949-48-5	FDA Pharmacology Review
Molecular formula	C221H366N72O67S (acetate salt: · x C2H4O2, x ≤ 7)	FDA label
Molecular weight	5135.9 Da (free base)	FDA label
Development code	TH9507	FDA Pharmacology Review
Class	Modified human growth hormone releasing factor (GHRH/GRF)	FDA Pharmacology Review
C-terminus	Amidated; "an amidated GHRH (1-44) peptide"	PMID 20943777

The N-terminal modification is the design point. FDA's pharmacology review notes that "the peptide's N-terminus is modified with a hexenoyl moiety to reduce enzymatic cleavage", which is what distinguishes tesamorelin from native GRF as a molecule.

What the research reports: the GRF receptor, GH, and IGF-1 axis

The mechanism is described consistently across FDA labeling and the published literature as a three-step axis.

Step one, receptor binding. FDA's Mechanism of Action section states: "In vitro, tesamorelin binds and stimulates human GRF receptors with similar potency as the endogenous GRF."

Step two, pituitary GH release. The same section describes the endogenous pathway: GRF "is a hypothalamic peptide that acts on the pituitary somatotroph cells to stimulate the synthesis and pulsatile release of endogenous growth hormone (GH)."

Step three, IGF-1. FDA's Pharmacodynamics section states that "tesamorelin stimulates growth hormone secretion, and subsequently increases IGF-I and IGFBP-3 levels." This was quantified in the phase 3 literature, where "levels of IGF-I increased by 81.0% in the tesamorelin group" versus a 5.0% decrease on placebo (Falutz et al., N Engl J Med 2007; PMID 18057338).

A separate 2010 study in 13 healthy men examined the effect on endogenous GH pulsatility and insulin sensitivity, describing tesamorelin as "an amidated GHRH (1-44) peptide" (Stanley et al., J Clin Endocrinol Metab 2010; PMID 20943777).

This distinguishes a GHRH analog from growth hormone itself: the literature describes it as acting upstream, stimulating the pituitary to release its own GH in a pulsatile pattern, rather than supplying GH exogenously.

The regulatory status, stated precisely

This is where most pages about tesamorelin get the facts wrong, so it is worth being exact.

Original approval. NDA 022505, approved November 10, 2010 to Theratechnologies, Inc. (FDA approval letter).
It is no longer an NDA. On March 23, 2020, under section 7002(e)(4)(A) of the BPCI Act, tesamorelin acetate was deemed to be a biologics license. It appears on FDA's official transition list, and a later FDA action letter refers to the "Notification of 'Deemed' BLA letter issued on March 23, 2020" (BLA 022505/S-018, FDA 2024). As a 44-residue peptide it met the statutory "protein" definition.
Current product. EGRIFTA WR, BLA 022505/S-020, approved March 25, 2025 (FDA approval letter). The label prints "Initial U.S. Approval: 2010".

The approved indication belongs to a product, not to a molecule. FDA's 2025 labeling states that "EGRIFTA WR is indicated for the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy." That describes what FDA licensed for a specific finished product, manufactured under a specific license, for a specific patient population. It is not a description of a research reference material.

FDA's own Limitations of Use in that same labeling are equally part of the record, and are frequently omitted by pages that quote the indication:

"EGRIFTA WR is not indicated for weight loss management as it has a weight neutral effect."

"Long-term cardiovascular safety of EGRIFTA WR has not been established."

The accurate framing is therefore: tesamorelin is the active ingredient in an FDA-licensed biologic. A research reference material is not that licensed product, is not manufactured or labeled under BLA 022505, and is not itself an FDA-approved or FDA-licensed drug.

The published trial literature

Study	Design	Citation
Phase 3, 26 weeks	412 patients, randomized, placebo-controlled, multicenter (NCT00123253)	PMID 18057338 (N Engl J Med 2007)
Extension to 52 weeks	Long-term extension of the above	PMID 18690162 (AIDS 2008)
Phase 3, 12 months	404 patients, randomized, placebo-controlled, two sequential phases	PMID 20101189 (J Acquir Immune Defic Syndr 2010)
Pooled analysis	Both phase 3 trials with safety extension, n=806	PMID 20554713 (J Clin Endocrinol Metab 2010)
Mechanistic	13 healthy men, GH pulsatility and insulin sensitivity	PMID 20943777 (J Clin Endocrinol Metab 2010)

Table describes published trials of the licensed drug product in specific clinical populations. It is not a statement of effectiveness, safety, or suitability of any research material for any use, and nothing in it is guidance for use in or on the body.

Unlike many compounds in this catalog, tesamorelin's evidence base includes controlled human trials, because it was developed as a pharmaceutical. That is a meaningful contrast with compounds such as KPV or BPC-157, whose literature is entirely or almost entirely preclinical. It also means the human data describes a licensed product in an HIV-associated lipodystrophy population, not a research material in a laboratory.

For laboratory use, tesamorelin is selected and handled as a reference material defined by analytical attributes: identity (for example by mass spectrometry) and purity (for example by HPLC). Those attributes, documented on a batch-specific Certificate of Analysis, are the appropriate basis for choosing a research compound. See how to read a peptide COA.

Sourcing COA-verified tesamorelin

Nox Amino stocks research-grade reference materials with batch-specific Certificates of Analysis. To view COA-verified tesamorelin, see the product detail page at /shop/tesamorelin, or review the current batch report at /coas/NoxR2602190080. Browse the full catalog at /shop.

Create a free account to view COA-verified tesamorelin, access batch-specific analytical data, and see member pricing. → Create your account

This article cites third-party research, FDA records, and registry entries for informational and laboratory-research purposes only. Nox Amino sells research compounds intended for laboratory and analytical use only, not for human or animal consumption. Nothing on this page is medical advice. Statements describing approved drug products describe those products only. Editorial methodology and review process: /learn/editorial-standards.

Frequently Asked Questions

What is tesamorelin?

Tesamorelin is a synthetic analog of human growth hormone-releasing factor (GRF), also called GHRH. FDA's approved labeling describes it as comprising the 44 amino acid sequence of human GRF plus a hexenoyl moiety, a C6 chain with a double bond at position 3, attached to the N-terminal tyrosine residue. Its FDA-documented chemical name is N-(trans-3-hexenoyl)-human growth hormone releasing factor (1-44) acetate, CAS 218949-48-5, molecular formula C221H366N72O67S, molecular weight 5135.9 Da as the free base. Its development code name was TH9507. As stocked by Nox Amino, tesamorelin is a reference material for laboratory research use only.

How does the literature describe the tesamorelin mechanism?

As a GRF receptor agonist acting on the growth hormone axis. FDA's approved labeling states that in vitro, tesamorelin binds and stimulates human GRF receptors with similar potency as the endogenous GRF, and that GRF acts on pituitary somatotroph cells to stimulate synthesis and pulsatile release of endogenous growth hormone. The labeling further states that tesamorelin stimulates growth hormone secretion and subsequently increases IGF-I and IGFBP-3 levels. This is the receptor pharmacology chain: GRF receptor, then pituitary GH release, then IGF-1.

Is tesamorelin FDA approved?

Tesamorelin is the active ingredient in an FDA-licensed biologic, which is a precise and important distinction. It was originally approved as NDA 022505 on November 10, 2010 to Theratechnologies. On March 23, 2020, under section 7002(e)(4)(A) of the BPCI Act, it was deemed to be a biologics license, so the approval is now BLA 022505. That license covers specific finished products, currently EGRIFTA WR. A research reference material is not that licensed product, is not manufactured or labeled under BLA 022505, and is not itself an FDA-approved or FDA-licensed drug.

What is the approved indication, and what did FDA exclude?

FDA's 2025 labeling states that EGRIFTA WR is indicated for the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy. That is a statement of what FDA licensed for a specific finished product in a specific patient population, and it is not a description of any research material. FDA's own Limitations of Use in that same labeling state that EGRIFTA WR is not indicated for weight loss management as it has a weight neutral effect, and that long-term cardiovascular safety has not been established.

What trial literature exists on tesamorelin?

Two phase 3 trials in HIV-infected patients were published, along with a pooled analysis. Falutz et al. (N Engl J Med 2007, PMID 18057338) reported a 26-week randomized placebo-controlled multicenter trial in 412 patients, registered as NCT00123253. Falutz et al. (J Acquir Immune Defic Syndr 2010, PMID 20101189) reported a 12-month randomized placebo-controlled trial in 404 patients. Falutz et al. (J Clin Endocrinol Metab 2010, PMID 20554713) pooled both phase 3 trials with safety extension data across 806 patients. This literature concerns the licensed drug product in a specific clinical population.