Educational reference. Research use only.
Tesamorelin: Mechanism, Research, and Regulatory Status
Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH) carrying an N-terminal trans-3-hexenoic acid group, CAS 106612-30-6, molecular weight 5135.89 Da. Tesamorelin has been studied in 4 published human trials summarized here, including two Phase 3 trials. Tesamorelin is FDA-approved as Egrifta for one indication; research-grade material is for laboratory use only.
Listed in the Veridian catalog as Tsamorelin.
Last reviewed 2026-09-29
What is Tesamorelin?
Tesamorelin key facts
Tesamorelin, listed in the Veridian catalog as Tsamorelin, is a synthetic analog of human growth hormone-releasing hormone (GHRH) with CAS number 106612-30-6 and a molecular weight of 5135.89 Da. A trans-3-hexenoic acid group on the N-terminus makes tesamorelin resistant to cleavage by dipeptidyl peptidase-4, the enzyme that inactivates native GHRH. Tesamorelin binds the GHRH receptor on pituitary somatotrophs and stimulates pulsatile growth hormone secretion, which raises IGF-1. In a Phase 3 trial in HIV-associated abdominal fat accumulation (Falutz and colleagues, New England Journal of Medicine, 2007, n=412), visceral adipose tissue fell 15.2% versus a 5.0% rise with placebo. A second Phase 3 trial with a safety extension (Falutz and colleagues, JAIDS, 2010, n=404) reported a 10.9% versus 0.6% visceral fat reduction at six months. Baker and colleagues (Archives of Neurology, 2012, n=152) measured cognitive outcomes in older adults. Tesamorelin is FDA-approved as Egrifta for HIV-associated lipodystrophy, is prohibited by WADA under S2, and research-grade material is supplied for laboratory research use only.
How does Tesamorelin work?
Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH, also known as somatocrinin), with a trans-3-hexenoic acid group attached to the N-terminus. That modification makes it resistant to cleavage by dipeptidyl peptidase-4 (DPP-4), the enzyme that normally breaks GHRH down, so it stays active longer than native GHRH(1–44). Tesamorelin binds to and activates the GHRH receptor (GHRHR) on pituitary somatotrophs, the pituitary cells that make growth hormone.
This stimulates pulsatile secretion of growth hormone (GH) through Gsα/adenylyl cyclase/cAMP/PKA signaling. GH in turn stimulates hepatic and peripheral production of IGF-1 (insulin-like growth factor 1), which carries out many of the anabolic and metabolic effects. Unlike exogenous GH, tesamorelin preserves pulsatile GH release and keeps feedback regulation through somatostatin intact, giving a more physiological GH profile.
FDA approved tesamorelin (Egrifta®) in 2010 for reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It was the first GHRH analog approved in the US. Research interest extends to aging-related GH decline, cognition, and metabolic syndrome.
What has research on Tesamorelin found?
What published peer-reviewed research and preclinical studies have established about Tesamorelin:
- 01FDA-approved (Egrifta®) for HIV-associated lipodystrophy since 2010. It is the only approved GHRH analog in the US
- 02Phase 3 RCT (Falutz et al., NEJM 2007, n=412, 26 weeks): tesamorelin reduced visceral adipose tissue by −15.2% vs +5.0% placebo (p<0.001)
- 03Unlike exogenous GH, tesamorelin preserves pulsatile GH secretion and somatostatin feedback, giving a more physiological GH profile
- 04Phase 2 data in adults with abdominal obesity (non-HIV): significant VAT reduction and improved lipid profiles
- 05Cognition research: a 20-week randomized, placebo-controlled trial (Baker et al., Arch Neurol 2012, n=152) in healthy older adults and adults with mild cognitive impairment reported a favorable effect on executive function
- 06Stimulates IGF-1 to within physiological young-adult reference ranges without driving supraphysiological levels
- 07Triglycerides fell by 50 mg/dL with tesamorelin vs a 9 mg/dL rise with placebo, and the total-to-HDL cholesterol ratio improved, in the 26-week Phase 3 HIV trial (Falutz 2007)
Which studies have examined Tesamorelin?
GHRH Phase 3: HIV Lipodystrophy
Phase 3 RCT · 2007Tesamorelin arm: VAT −15.2% vs placebo +5.0%; triglycerides −50 vs +9 mg/dL; IGF-1 +81.0% vs −5.0% (all p<0.001); no significant differences in glycemic measures
GHRH Phase 3: second trial with safety extension
Phase 3 extension · 2010VAT −10.9% vs −0.6% placebo at 6 months (p<0.0001); about 18% reduction in patients continuing to 12 months; the initial VAT improvement was rapidly lost in those switched to placebo; no change in glucose parameters
GHRH analog and cognitive function (MCI and healthy older adults)
Phase 2 RCT · 2012Favorable effect on cognition vs placebo (intent-to-treat p=0.03), driven by executive function (p=0.005) with a trend in verbal memory (p=0.08); IGF-1 rose 117% within the physiological range; adverse events were mild but more frequent than placebo (68% vs 36%)
GH pulsatility and insulin sensitivity in healthy men
Open-label mechanistic study · 2011Increased mean overnight GH, GH peak area and basal GH secretion; IGF-1 rose by 181 μg/L; no significant change in fasting glucose or insulin-stimulated glucose uptake
Frequently asked questions about Tesamorelin
How does tesamorelin differ from exogenous growth hormone?+
Tesamorelin stimulates the pituitary to release endogenous GH in pulses, preserving the natural feedback loop via somatostatin. Exogenous GH produces a supraphysiological elevation that bypasses those regulatory mechanisms. This means tesamorelin maintains more physiological IGF-1 levels and a natural pulsatile GH profile, which is associated with fewer side effects (edema, insulin resistance, acromegalic changes) than exogenous GH.
How should lyophilized tesamorelin be stored?+
Lyophilized powder: −20°C in a sealed, opaque container away from moisture. The trans-3-hexenoic acid modification is stable but should be protected from oxidative conditions. Allow to warm to room temperature before opening.
Is tesamorelin being studied in aging populations?+
Yes. GH secretion declines ~14% per decade after age 30 (somatopause). Research has evaluated tesamorelin in older adults to restore GH pulsatility, preserve lean mass, reduce visceral fat, and improve cognitive function. A 20-week randomized, placebo-controlled trial (Baker et al., Arch Neurol 2012) in 152 adults aged 55 to 87, with and without mild cognitive impairment, reported a favorable effect on executive function; the authors called for longer trials before drawing conclusions about brain health.
What is tesamorelin's effect on IGF-1?+
In clinical trials, tesamorelin raised IGF-1 from below-normal to within the physiological reference range for young adults (~150–350 ng/mL) in HIV lipodystrophy patients. Mean IGF-1 SD score increased from −1.0 to +0.2 at 26 weeks. This normalization, rather than supraphysiological elevation, is considered a key safety advantage. Monitoring IGF-1 levels is standard practice in tesamorelin research to avoid excessive elevation.
Is tesamorelin prohibited in sport?+
Yes. WADA classifies all GHRH analogs, including tesamorelin, under the S2 Prohibited List (Peptide Hormones, Growth Factors, Related Substances). Athletes subject to anti-doping rules may not use tesamorelin, even with a therapeutic use exemption, outside of very narrow medical necessity criteria. This classification applies even though tesamorelin is FDA-approved for lipodystrophy.
Can tesamorelin be combined with other peptides in research?+
Tesamorelin (GHRH analog) and GH secretagogues like ipamorelin act on synergistic pathways. GHRH amplifies GH pulse amplitude, while GH secretagogues (acting via the ghrelin receptor GHS-R1a) increase pulse frequency. Combination in preclinical models produces additive GH release. Researchers studying GH axis optimization often evaluate this combination, though clinical safety data for the combination is limited.
What metabolic parameters improve with tesamorelin beyond VAT reduction?+
In Phase 3 HIV lipodystrophy trials, tesamorelin produced: −50 mg/dL triglycerides vs +9 mg/dL on placebo (Falutz 2007), reduction in non-HDL cholesterol, slight improvement in HDL, and a modest reduction in carotid intima-media thickness (IMT), a surrogate for cardiovascular risk. No significant change in total cholesterol or fasting glucose was observed, and insulin resistance was not meaningfully worsened.
References & sources
Every citation below was resolved against its primary source before publication. Each PMID was checked against its PubMed record and each DOI through doi.org. Follow any link to read the paper at the publisher rather than taking our summary on trust.
- [1]Falutz J, Allas S, Blot K, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine. 2007. PMID: 18057338 DOI: 10.1056/NEJMoa072375
- [2]Stanley TL, Chen CY, Branch KL, et al. Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men. Journal of Clinical Endocrinology & Metabolism. 2011. PMID: 20943777 DOI: 10.1210/jc.2010-1587
- [3]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. Journal of Acquired Immune Deficiency Syndromes. 2010. PMID: 20101189 DOI: 10.1097/QAI.0b013e3181cbdaff
- [4]Dhillon S. Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy. Drugs. 2011. PMID: 21668043 DOI: 10.2165/11202240-000000000-00000
- [5]Friedman SD, Baker LD, Borson S, et al. Growth hormone-releasing hormone effects on brain γ-aminobutyric acid levels in mild cognitive impairment and healthy aging. JAMA Neurology. 2013. PMID: 23689947 DOI: 10.1001/jamaneurol.2013.1425
- [6]Baker LD, Barsness SM, Borson S, et al. Effects of growth hormone–releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Archives of Neurology. 2012. PMID: 22869065 DOI: 10.1001/archneurol.2012.1970
- [7]Lo J, You SM, Canavan B, et al. Low-dose physiological growth hormone in patients with HIV and abdominal fat accumulation: a randomized controlled trial. JAMA. 2008. PMID: 18677023 DOI: 10.1001/jama.300.5.509
- [8]Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism. 2006. PMID: 17018654 DOI: 10.1210/jc.2006-1702
Where this data comes from
- Citations & trial data: PubMed (NCBI, U.S. National Library of Medicine), Crossref and ClinicalTrials.gov.
- Chemical identity: PubChem and UniProt. Where sources conflicted, the disputed value is omitted rather than guessed.
- Regulatory status: U.S. FDA publications and, where applicable, the WADA Prohibited List. Compounding status changes often, so check FDA directly before relying on it.
- Purity, form and storage are handling and supplier conventions, not literature-derived values. Confirm against the lot-specific certificate of analysis. General handling is covered in the storage and stability guide.
Content last reviewed 2026-09-29. Compiled by Veridian Research from the primary literature. This page is an educational reference for laboratory researchers. It is not medical advice, and it describes no human use.
Is Tesamorelin approved for human use?
Tesamorelin is FDA-approved as Egrifta® for reduction of excess abdominal fat in HIV-infected adults with lipodystrophy. Use outside this indication is investigational. WADA classifies all GHRH analogs, including tesamorelin, as prohibited under S2. For research purposes outside approved indications only.
Research-use-only material
Specifications and certificate of analysis
Tesamorelin is stocked as a research reagent. Analytical documentation, covering identity, purity and the lot-specific certificate of analysis, is published in the certificate library.