Tesamorelin Acetate
Tesamorelin | Egrifta | TH9507
Mechanism of Action
Tesamorelin is a synthetic analogue of human GHRH (growth hormone-releasing hormone) comprising all 44 amino acids of native GHRH with an added trans-3-hexenoic acid moiety at the N-terminus. This modification enhances resistance to DPP-4 enzymatic degradation without altering receptor binding affinity, resulting in improved bioavailability compared to native GHRH. Tesamorelin is FDA-approved under the brand name Egrifta for the treatment of excess visceral abdominal fat in HIV-infected patients with lipodystrophy.
Tesamorelin binds to GHRH receptors on anterior pituitary somatotrophs, stimulating GH synthesis and secretion through the cAMP/PKA signaling cascade. Like sermorelin, it promotes physiological pulsatile GH release while preserving somatostatin-mediated feedback regulation. The resulting GH elevation stimulates hepatic IGF-1 production and downstream metabolic effects including lipolysis, particularly in visceral adipose depots.
Clinical trials demonstrated significant reductions in visceral adipose tissue (VAT) — approximately 15-18% reduction over 26 weeks in HIV lipodystrophy patients. Importantly, tesamorelin reduced VAT without significantly affecting subcutaneous fat, suggesting preferential action on metabolically active visceral depots. Additional research has explored cognitive benefits, with Stanley et al. demonstrating improved executive function and verbal memory in older adults.
Key Research Findings
- Falutz et al. (2007) demonstrated tesamorelin reduced trunk fat by 15.2% and VAT by 18% over 26 weeks in HIV-associated lipodystrophy in the pivotal Phase III trial.
- Stanley et al. (2015) showed tesamorelin improved executive function and verbal memory in cognitively normal older adults with elevated abdominal adiposity.
- Dhillon (2011) reviewed the pharmacology of tesamorelin, confirming its mechanism through GHRH receptor agonism and its specificity for visceral fat reduction.
- Falutz et al. (2010) demonstrated that benefits of tesamorelin on VAT are maintained with continued treatment over 52 weeks.
References
Dosage in Research
The FDA-approved dose is 2 mg subcutaneously once daily. Clinical trials used 1-2 mg daily doses. Diagnostic GH stimulation protocols have also been studied.
Storage & Handling
Store lyophilized powder at -20C. Reconstituted solution should be refrigerated at 2-8C and used within 14 days. Protect from light.
Frequently Asked Questions
What is Tesamorelin?
Tesamorelin is an FDA-approved synthetic GHRH analogue (brand name Egrifta). It contains all 44 amino acids of natural GHRH with an N-terminal modification that improves stability. It is approved for reducing excess visceral fat in HIV-associated lipodystrophy.
How does tesamorelin differ from sermorelin?
Both target the GHRH receptor, but sermorelin is a truncated 29-amino-acid fragment while tesamorelin contains all 44 amino acids plus a stabilizing N-terminal modification. Tesamorelin has better bioavailability and a more robust clinical evidence base, having completed Phase III trials.
What research exists on cognitive effects?
Stanley et al. at Massachusetts General Hospital demonstrated tesamorelin improved executive function and verbal memory in healthy older adults. The mechanism may involve GH/IGF-1-mediated neuroprotective effects or indirect benefits from reduced visceral adiposity.
Source Tesamorelin Acetate for your research
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