Tesamorelin

Tesamorelin is a synthetic analog of growth-hormone-releasing hormone (GHRH) modified with a trans-3-hexenoic acid group at the N-terminus, a structural change that confers resistance to degradation by dipeptidyl peptidase-4 (DPP-4) and substantially extends its biological half-life relative to native GHRH. This stabilization allows sustained engagement of the pituitary GHRH receptor and more consistent stimulation of growth hormone and downstream IGF-1 release than shorter-acting GHRH fragments provide, making it a useful reference compound for studying prolonged receptor occupancy effects. Tesamorelin's research credibility is reinforced by its status as an FDA-approved drug, marketed as Egrifta for HIV-associated lipodystrophy, which has generated an extensive body of controlled human data on its effects on visceral adipose tissue, muscle composition, and body fat distribution. As unapproved-source research material offered here strictly for laboratory use, it remains widely studied for probing DPP-4-resistant GHRH pharmacology, visceral fat metabolism, and GH-axis regulation in preclinical and translational research models. Peptides.SO currently aggregates 179 supplier listings for Tesamorelin from 95 distinct vendors, 179 of them in stock as of September 2026; across the 61 listings whose quantities normalize to a per-milligram basis the median price is $11.00/mg, with the middle half of the market between $9.00 and $15.00/mg.

Mechanism of Action:

Tesamorelin binds selectively to the pituitary GHRH receptor (GHRHr), a class B G-protein-coupled receptor coupled to Gs and adenylyl cyclase. Receptor activation raises intracellular cAMP, which stimulates protein kinase A and triggers downstream transcription of growth hormone. Because DPP-4 cleaves native GHRH(1-44) at the His2-Ala3 bond within minutes of injection, the N-terminal trans-3-hexenoic acid modification blocks this proteolytic site, extending the plasma half-life of tesamorelin to approximately 26–38 minutes versus under 7 minutes for unmodified GHRH. This metabolic stability maintains pulsatile GH release patterns that respect the hypothalamic-pituitary-IGF-1 negative feedback axis, in contrast to exogenous GH administration, which suppresses endogenous GH secretory mechanisms. Downstream, IGF-1 mediates most of the tissue-level effects studied in preclinical models: increased lipolysis in visceral adipocytes, shifts in substrate oxidation, and changes in lean-to-fat mass ratios. Researchers studying tesamorelin typically monitor pulsatile GH profiles, serum IGF-1 AUC, and IGFBP-3 as proxies for GHRH receptor engagement efficiency.

Key Research Studies:

Falutz J et al. conducted randomized trials (NCT00569660, NCT00642590) demonstrating that tesamorelin 2 mg/day in HIV-positive subjects with lipodystrophy reduced visceral adipose tissue area by a mean of 15–18% versus placebo over 26 weeks, with significant increases in IGF-1 and significant reductions in trunk fat; effects were largely reversed upon discontinuation, confirming mechanism dependence. PubMed PMID: 20921997.

Stanley TL et al. studied tesamorelin in HIV-uninfected subjects with abdominal obesity and found significant reductions in visceral fat and improvements in triglyceride and non-HDL cholesterol levels, with no worsening of glucose tolerance, positioning tesamorelin as a research tool for understanding GH-mediated fat partitioning outside the HIV context. PubMed PMID: 22593590.

Makimura H et al. examined tesamorelin versus placebo effects on visceral fat, carotid intima-media thickness, and cognitive function in HIV-positive adults with cognitive impairment, finding reductions in visceral fat and improvements in selected executive function measures over 26 weeks, opening a translational research direction linking GH-axis activity to neurocognitive endpoints. PubMed PMID: 27219260.

Research Concentrations Used in Studies:

Clinical and translational studies have used subcutaneous tesamorelin doses of 1–2 mg once daily. In preclinical rodent models, weight-adjusted dosing typically ranges from 100–300 mcg per injection in standard pharmacokinetic and receptor-occupancy studies. Laboratory reconstitution typically uses bacteriostatic water at concentrations of 1–2 mg/mL for subcutaneous application in animal models; higher concentrations (2–4 mg/mL) can be prepared for smaller injection volumes in rat studies while maintaining peptide stability. As with all GHRH analogs, reconstituted solutions should be stored at 4°C and used within 7–14 days of preparation under sterile conditions.

Potential Research Applications:

DPP-4-resistant GHRH receptor pharmacodynamics and receptor occupancy studies Visceral adipose tissue and body composition modeling in metabolic disease contexts GH-axis and IGF-1 regulation in metabolic research across lifespan models Lipodystrophy and fat redistribution mechanism studies Muscle composition and lean mass research in catabolic or HIV-associated states Comparative half-life and stability studies among GHRH analogs (versus sermorelin, CJC-1295) Neurocognitive correlates of GH-axis manipulation in aging models Cardiometabolic risk factor research linking GH secretion to triglyceride and HDL metabolism

Safety Profile from Published Research:

In pivotal controlled trials, tesamorelin demonstrated a safety profile consistent with mild GH-axis stimulation: the most common adverse events were injection-site reactions (erythema, pruritus, edema), transient arthralgias, and fluid retention. Glucose intolerance was not significantly worsened in most arms; however, because GH is known to be counter-regulatory to insulin, monitoring of fasting glucose and HbA1c is standard practice in any research protocol using GHRH analogs. No pituitary suppression or rebound was observed on discontinuation. Tesamorelin should not be used in subjects with pituitary disease, active malignancy, or pregnancy in any research protocol. All use of material supplied here is strictly for laboratory research use only (RUO); it carries no therapeutic indication.

Marketplace Snapshot (September 2026, Peptides.SO listings data): Tracked listings: 179 from 95 distinct suppliers (179 in stock) Listings with a verifiable per-mg price: 61 Median price per mg: $11.00 (interquartile range $9.00 to $15.00) Lowest verified per-mg price: available on the live comparison table above Listings that price by kit, bundle, or unit rather than by weight cannot be normalized to a per-mg basis and are excluded from the figures above. Prices change frequently; the live comparison table on this page reflects the most recent crawl.

Frequently Asked Questions:

Q: What is the key structural difference between tesamorelin and sermorelin? A: Sermorelin is GHRH(1-29) with no modifications; tesamorelin is GHRH(1-44) bearing a trans-3-hexenoic acid group at its N-terminus. The hexenoic acid blocks the DPP-4 cleavage site, extending plasma half-life to roughly 26–38 minutes versus under 7 minutes for sermorelin. Tesamorelin therefore provides more sustained receptor engagement per injection in pharmacokinetic comparisons.

Q: Why is DPP-4 resistance relevant to a GHRH analog research program? A: DPP-4 rapidly inactivates native GHRH and any unprotected fragment by cleaving the N-terminal His-X dipeptide. A DPP-4-resistant analog like tesamorelin allows researchers to study sustained GHRH receptor pharmacology without the confounding variable of rapid in vivo degradation, and to characterize downstream GH and IGF-1 kinetics in a more controlled way than is possible with short-acting sequences.

Q: How does tesamorelin differ from CJC-1295 as a GHRH analog research tool? A: CJC-1295 is engineered for ultra-long half-life via covalent albumin binding (Drug Affinity Complex technology), producing a half-life of days rather than minutes. Tesamorelin's half-life is substantially shorter, allowing study of pulsatile GH release patterns more similar to endogenous physiology, whereas CJC-1295 essentially produces sustained, flat GH elevation — a meaningful experimental difference when the research question concerns pulsatility or axis feedback.

Q: What tissues have been most studied as downstream targets of tesamorelin? A: Visceral adipose tissue (VAT) is the best-characterized endpoint; mesenteric and omental fat compartments respond to IGF-1-mediated lipolytic signaling. Beyond VAT, liver fat, carotid intima-media thickness, and neurocognitive function have been investigated as secondary endpoints in translational studies, reflecting the broad role of the GH-IGF-1 axis in metabolic and cardiovascular homeostasis.

Q: Is tesamorelin approved for human use? A: Yes, as Egrifta (tesamorelin for injection) for the treatment of HIV-associated lipodystrophy in adults. Material listed on this platform is unapproved-source research chemical supply for laboratory investigation only, separate from any licensed pharmaceutical product.

Related Research on Peptides.SO: peptides.so/peptide/sermorelin peptides.so/peptide/cjc-1295-no-dac-5mg peptides.so/learn/how-to-reconstitute-peptides peptides.so/learn/peptide-storage-best-practices peptides.so/tools/calculator

Cited Research: Falutz J et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine. 2007. PubMed PMID: 17804842. Falutz J et al. Long-term safety and effects of tesamorelin, a growth hormone-releasing factor analogue, in HIV patients with abdominal fat accumulation. AIDS. 2008. PubMed PMID: 20921997. Stanley TL et al. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation. JAMA. 2012. PubMed PMID: 22593590. Makimura H et al. Tesamorelin effects on brain structure and cognition in HIV-infected adults. Journal of Infectious Diseases. 2016. PubMed PMID: 27219260.

For laboratory research only. Not for human or veterinary use, diagnosis, treatment, cure, or prevention of any disease. THIS PRODUCT IS NOT FOR HUMAN CONSUMPTION.