Tesamorelin

Mechanism

Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH) stabilized against rapid enzymatic degradation. Unlike direct exogenous growth hormone, tesamorelin works upstream — it stimulates the pituitary to release GH in the body's natural pulsatile pattern, which preserves the negative-feedback loops that regulate the GH–IGF-1 axis.

This mechanism distinguishes tesamorelin from related GH-axis compounds. Direct exogenous human growth hormone (hGH) bypasses the pituitary entirely; ghrelin-receptor agonists (ipamorelin, MK-677) act on a different receptor family. Tesamorelin specifically activates GHRH receptors.

The compound is FDA-approved as Egrifta for HIV-associated lipodystrophy (visceral fat reduction). Research-protocol use outside that indication is what most vendor catalog listings target.

Research dosing

The approved Egrifta dose is 2 mg daily subcutaneous, administered before bed to align with the natural overnight GH pulse. Research-protocol literature follows the same schedule:

• 1 mg daily as a lower-end protocol dose
• 2 mg daily matching the FDA-approved schedule
• Cycling is common — 12-week on / 4-week off cycles appear in research-protocol writeups

Half-life is short (~30 minutes), which is why the timing of administration matters. The pituitary response continues for several hours after the peptide itself has been cleared.

Side-effect profile

Reported side effects from clinical and research-protocol literature cluster in three categories:

• Injection-site reactions — most-reported; generally mild
• Joint stiffness / mild edema — class effect of GH-axis compounds; typically resolves with cycling
• Glucose tolerance changes — modest; monitored in clinical trials

What we cover

Vendor audits for tesamorelin focus on identity confirmation and purity at scale. The compound is structurally complex (44 amino acids), and lower-quality synthesis routes produce truncated peptide fragments that show up on HPLC as secondary peaks. We weight the per-batch HPLC chromatogram heavily for tesamorelin specifically.