Tesamorelin
A stabilized GHRH analog studied for visceral fat reduction, IGF-1 elevation, and cognitive effects through pulsatile growth hormone release.
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What is Tesamorelin?
Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH), structurally based on the full 44-amino-acid sequence of native GHRH with a single critical modification: a trans-3-hexenoic acid group attached to the N-terminal tyrosine. This hexenoyl modification protects the peptide from rapid degradation by dipeptidyl peptidase-4 (DPP-4), the enzyme that inactivates native GHRH within minutes of secretion. The peptide was developed by Theratechnologies and is among the few growth hormone secretagogues to receive FDA approval, marketed as Egrifta for a specific clinical indication.
Tesamorelin is notable in research for its preferential effects on visceral adipose tissue and for being one of the most clinically validated GHRH analogs in current use. Beyond its approved indication of HIV-associated lipodystrophy, tesamorelin has been investigated in research contexts including non-alcoholic fatty liver disease, HIV-associated neurocognitive disorders, and cognitive function in aging populations. The pulsatile pharmacokinetic profile distinguishes it from longer-acting GHRH analogs and supports physiological GH release patterns.
Mechanism of action
Tesamorelin’s mechanisms of action have been investigated across multiple pathways:
- GHRH receptor activation: The peptide binds and activates the growth hormone-releasing hormone receptor (GHRHR) on pituitary somatotrophs, stimulating endogenous growth hormone synthesis and release through cAMP-dependent signaling.
- Protease resistance via hexenoyl modification: The trans-3-hexenoic acid group at the N-terminus blocks cleavage by DPP-4, extending effective half-life enough for therapeutic use while preserving pulsatile GH release patterns.
- Preferential visceral fat effects: Research has documented preferential reductions in visceral adipose tissue over subcutaneous fat, likely mediated by tissue-specific GH receptor distribution and lipolytic signaling.
- IGF-1 elevation: Sustained use elevates serum insulin-like growth factor 1, the primary mediator of GH’s anabolic effects, with IGF-1 serving as a biomarker for monitoring downstream effects.
- Preserved feedback regulation: Unlike exogenous growth hormone, tesamorelin works through the natural physiological pathway, preserving negative feedback regulation by IGF-1 and somatostatin.
These pathways are characterized in both preclinical models and human clinical research.
Research applications
Tesamorelin has been investigated across several research domains, with the most active areas including:
- Visceral adipose tissue research: Phase 3 trials demonstrated significant reductions in visceral adipose tissue (approximately 15-17% over 26 weeks) with associated improvements in waist circumference, triglycerides, and certain cardiovascular biomarkers.
- Non-alcoholic fatty liver disease research: Studies in HIV-positive populations with NAFLD documented significant reductions in liver fat content, with research interest extending to non-HIV NAFLD populations.
- Cognitive function research: Trials in healthy older adults and adults with mild cognitive impairment examined effects on executive function, verbal memory, and brain volumetric measures, drawing on GHRH and GH/IGF-1 signaling roles in neurogenesis and synaptic plasticity.
- HIV-associated neurocognitive disorders: Randomized research has examined potential effects on HIV-associated cognitive impairment, with findings suggesting modest improvements in executive function and verbal memory.
- Body composition research: Studies have examined effects on lean mass, fat distribution, and metabolic parameters in research populations beyond the original approved indication.
This compound is intended for laboratory research use only. It has not been approved for human therapeutic use by any regulatory agency.
Storage & reconstitution
In its lyophilized form, tesamorelin tolerates ambient temperatures during shipping but should be stored long-term at -20°C, protected from light. Properly stored lyophilized peptide remains stable for 24 months or longer.
Once reconstituted with sterile or bacteriostatic water for injection, tesamorelin solutions should be stored refrigerated at 2-8°C and used within 28 days. Avoid repeated freeze-thaw cycles, which can degrade peptide structure and reduce activity.
Visual inspection should be performed before each use. The reconstituted solution should be clear and colorless. Reject any solution that appears cloudy, discolored, or contains visible particulate matter.
For step-by-step reconstitution calculations, see our reconstitution calculator.
For laboratory research use only. The compound described on this page is intended exclusively for in vitro research and laboratory experimentation by qualified researchers and is not for human or veterinary use. It is not a drug, food, dietary supplement, or cosmetic, and has not been approved by the FDA, Health Canada, EMA, or any other regulatory authority for the diagnosis, treatment, cure, mitigation, or prevention of any disease or medical condition. The information provided on this page is for educational and reference purposes only and does not constitute medical advice. By accessing this content you confirm that you are a qualified researcher purchasing for legitimate laboratory purposes.