Trans-3-Hexenoic Acid Modified GHRH Analog — GHRH Receptor Activation & Visceral Fat Reduction
The only FDA-approved GHRH analog. Full 44-amino-acid GHRH sequence with N-terminal modification for DPP-IV resistance.
Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH) that carries the complete 44-amino-acid GHRH sequence with one key modification: a trans-3-hexenoic acid group attached to the N-terminus. This modification makes it resistant to the enzyme that normally breaks down GHRH in the bloodstream, extending its biological activity.
What makes tesamorelin unique in this compound library is that it is the only GHRH analog to receive FDA approval. Since 2010, it has been sold under the brand name Egrifta® for reducing excess abdominal fat in HIV patients on antiretroviral therapy — a condition called lipodystrophy. This means it has completed the full Phase III clinical trial process, giving it a human safety and efficacy dataset that most research peptides simply do not have.
Beyond its approved indication, tesamorelin is studied for body composition optimization in non-HIV populations and, more recently, for cognitive function in older adults. The research-grade lyophilized powder supplied by Purgo Labs is for laboratory use only and differs from the clinical Egrifta® formulation.
Research Use Only: Tesamorelin is supplied by Purgo Labs strictly for qualified laboratory research purposes. It is not intended for human or veterinary use, nor for diagnostic, therapeutic, or cosmetic application. Always consult a qualified healthcare professional before considering any peptide or supplement protocol. The information on this page is for educational and scientific reference only.
Tesamorelin binds to GHRH receptors (GHRHR) on somatotroph cells in the anterior pituitary. It carries the complete 44-amino-acid sequence of native GHRH, unlike sermorelin (29-aa fragment), giving it full-length receptor engagement.
GHRHR activation triggers adenylyl cyclase → cAMP → PKA cascade, phosphorylating transcription factors that drive GH gene expression and pulsatile GH secretion from somatotrophs.
The trans-3-hexenoic acid group conjugated to the N-terminal tyrosine blocks dipeptidyl peptidase IV (DPP-IV) cleavage — the primary mechanism of native GHRH degradation. This extends biological half-life to ~26 minutes vs. ~7 minutes for native GHRH.
Like sermorelin, tesamorelin preserves pulsatile GH secretion and maintains hypothalamic-pituitary feedback. Somatostatin continues to regulate output, preventing supraphysiological GH elevation.
Secreted GH activates hormone-sensitive lipase (HSL) in visceral adipocytes — which are particularly GH-sensitive due to higher GH receptor density and lower insulin anti-lipolytic sensitivity than subcutaneous fat.
GH drives hepatic IGF-1 production, mediating downstream anabolic, lipolytic, and tissue-repair effects. IGF-1 elevation is a pharmacodynamic marker used in tesamorelin clinical trials to confirm GH axis activation.
trans-3-hexenoic acid–Tyr–Ala–Asp–Ala–Ile–Phe–Thr–Asn–Ser–Tyr–Arg–Lys–Val–Leu–Gly–Gln–Leu–Ser–Ala–Arg–Lys–Leu–Leu–Gln–Asp–Ile–Met–Ser–Arg–Gln–Gln–Gly–Glu–Ser–Asn–Gln–Glu–Arg–Gly–Ala–Arg–Ala–Arg–Leu–NH₂
44 amino acids — complete native GHRH sequence with trans-3-hexenoic acid N-terminal conjugation for DPP-IV resistance. MW: 5,135.9 Da.
Tesamorelin (Egrifta®) is FDA-approved for reducing excess visceral adipose tissue (VAT) in HIV-infected patients on antiretroviral therapy. Phase III trials demonstrated ~15–20% VAT reduction over 26 weeks, with improvements in lipid profiles and patient-reported outcomes.
Beyond HIV lipodystrophy, tesamorelin is studied for visceral fat reduction in non-HIV populations. GH axis activation promotes lipolysis in metabolically active visceral depots, with potential implications for cardiometabolic risk reduction.
Baker et al. (2021, JAMA Network Open) investigated tesamorelin in older adults with mild cognitive impairment, finding improvements in executive function and verbal memory compared to placebo. The GH/IGF-1 axis has established roles in hippocampal neurogenesis and synaptic plasticity.
GH axis activation via tesamorelin increases IGF-1, which promotes protein synthesis and lean mass preservation. Research in HIV-positive subjects showed maintained or improved lean body mass alongside VAT reduction, suggesting a favorable body composition profile.
Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359–2370.
Phase III RCT demonstrating significant VAT reduction with tesamorelin vs. placebo in HIV-positive patients. Landmark study supporting FDA approval.
PubMed 18057338 →Falutz J, et al. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analogue, 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.
52-week extension confirming sustained VAT reduction, improved lipid profiles, and acceptable tolerability profile over long-term use.
PubMed 20101189 →Baker LD, 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. Arch Neurol. 2012;69(11):1420–1429.
Tesamorelin improved executive function and verbal memory in older adults with mild cognitive impairment, supporting the GH/IGF-1 axis role in cognition.
PubMed 22869065 →Dhillon S. Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy. Drugs. 2011;71(8):1071–1091.
Comprehensive review of tesamorelin pharmacology, clinical efficacy, and safety profile, confirming its role as the first FDA-approved GHRH analog.
PubMed 21668038 →All three are GHRH receptor agonists, but they differ substantially in structure, half-life, clinical validation, and GH release pattern. See the Sermorelin vs Tesamorelin and three-way GHRH comparison for full analysis.
| Aspect | Tesamorelin | Sermorelin | CJC-1295 |
|---|---|---|---|
| Amino acid length | 44 aa (full GHRH sequence) | 29 aa (N-terminal fragment) | 29 aa + DAC modification |
| Key modification | trans-3-hexenoic acid (N-terminal) | None — truncated native sequence | Drug Affinity Complex (DAC) for albumin binding |
| Half-life | ~26 minutes | ~10–20 minutes | ~6–8 days (with DAC) |
| GH release pattern | Pulsatile (physiological) | Pulsatile (physiological) | Sustained / blunted pulse |
| FDA approval | Yes — Egrifta® (HIV lipodystrophy) | Former (1997–2008, commercial withdrawal) | No |
| Primary clinical use | Visceral fat reduction, HIV lipodystrophy | GH deficiency, anti-aging | Body composition, GH optimization |
| Cognitive research | Yes — Phase II RCT (Baker et al.) | Limited | No dedicated studies |
| Feedback inhibition | Preserved (somatostatin active) | Preserved | Partially blunted |
| Human clinical data | Extensive (Phase III RCTs) | Moderate (Phase II/III, older studies) | Limited (Phase I/II) |
| Effect | Frequency | Severity | Notes |
|---|---|---|---|
| Injection site reactions | Common | Mild | Erythema, pruritus, pain, and induration at the injection site. Most common adverse event in Phase III trials (~25% of subjects). |
| Fluid retention / edema | Common | Mild–Moderate | GH-mediated sodium retention can cause peripheral edema, particularly in the first weeks of use. Usually resolves with dose adjustment. |
| Arthralgia / myalgia | Common | Mild | Joint and muscle pain reported in clinical trials. Mechanism involves GH-mediated fluid shifts and connective tissue effects. |
| Glucose dysregulation | Uncommon | Moderate (monitor in diabetics) | GH is counter-regulatory to insulin. Tesamorelin can reduce insulin sensitivity. HbA1c monitoring is recommended in subjects with impaired glucose tolerance or diabetes. |
| Nausea | Uncommon | Mild | Reported in a subset of trial participants. Less frequent than with GHRP-class peptides as tesamorelin does not activate ghrelin pathways. |
| IGF-1 elevation | Expected (pharmacodynamic) | Monitor | Tesamorelin reliably elevates serum IGF-1 as part of its mechanism. Supraphysiological IGF-1 is associated with theoretical proliferative risks. Baseline and follow-up monitoring is standard. |
| Hypersensitivity reactions | Rare | Potentially severe | Rare cases of urticaria, rash, and anaphylaxis reported in post-marketing surveillance. Discontinue if systemic hypersensitivity occurs. |
Use code HEALTH for 15% off
Tesamorelin (brand name Egrifta®) is FDA-approved for reducing excess visceral adipose tissue (VAT) in HIV-infected patients with antiretroviral therapy-associated lipodystrophy. In research settings, it is also studied for body composition optimization, metabolic syndrome, and cognitive function in older adults.
Yes. Tesamorelin was approved by the FDA in 2010 under the brand name Egrifta® for the treatment of HIV-associated lipodystrophy. It is the only GHRH analog to have received FDA approval, making it unique among research peptides in this class.
Tesamorelin carries the full 44-amino-acid GHRH sequence (vs. sermorelin's 29-aa fragment) and has an N-terminal trans-3-hexenoic acid modification that extends its half-life. Tesamorelin has FDA approval and extensive Phase III clinical data; sermorelin had FDA approval from 1997–2008 but was commercially withdrawn. Both preserve pulsatile GH secretion.
Tesamorelin preserves pulsatile GH secretion (physiological pattern) while CJC-1295 with DAC produces sustained GH elevation that blunts natural pulsatility. Tesamorelin has FDA approval and human Phase III data; CJC-1295 has limited Phase I/II data. For researchers prioritizing physiological GH dynamics, tesamorelin is the better-studied option.
The most common side effects in clinical trials were injection site reactions (~25%), fluid retention/edema, arthralgia, and myalgia. Glucose dysregulation is a concern in subjects with impaired insulin sensitivity. IGF-1 elevation is an expected pharmacodynamic effect that should be monitored.
Emerging research suggests yes. Baker et al. (2012, 2021) conducted Phase II RCTs showing tesamorelin improved executive function and verbal memory in older adults with mild cognitive impairment. The GH/IGF-1 axis has established roles in hippocampal neurogenesis and synaptic plasticity, providing a plausible mechanism.
Tesamorelin has a half-life of approximately 26 minutes — longer than native GHRH (~7 minutes) due to its DPP-IV-resistant N-terminal modification, but shorter than CJC-1295 with DAC (~6–8 days). This intermediate half-life allows for pulsatile GH stimulation while maintaining physiological feedback.
Medical Disclaimer: All content on this site is for educational and research purposes only. Research peptides are not FDA-approved for human use. Always consult a qualified healthcare professional before considering any peptide or supplement protocol. Nothing on this site constitutes medical advice, diagnosis, or treatment.