Summary

Tesamorelin is an N-terminally modified analogue of growth hormone-releasing hormone (GHRH) approved by the FDA (as Egrifta) for the treatment of HIV-associated lipodystrophy. It stimulates endogenous growth hormone release via the GHRH receptor. Unlike exogenous GH, it preserves physiological pulsatility. Evidence is strong for its approved indication, with ongoing research in cognitive ageing and body composition.

Mechanism

Tesamorelin is an agonist at the growth hormone-releasing hormone receptor (GHRH-R) on somatotroph cells in the anterior pituitary. The trans-3-hexenoyl modification at the N-terminus enhances resistance to enzymatic degradation by dipeptidyl peptidase IV (DPP-IV), extending the half-life to approximately 2–3 hours (compared to ~10 minutes for native GHRH). By stimulating endogenous GH release through the physiological GHRH pathway, tesamorelin preserves the pulsatile pattern of GH secretion, which is important for maintaining the normal balance between GH and somatostatin signalling.

Evidence base

Evidence Grading: Strong (for approved indication)

Tesamorelin has robust Phase III clinical trial data supporting its FDA-approved indication. Evidence for other applications is emerging.

Key studies:

  • Falutz J, et al. (2010) — pivotal Phase III trials demonstrating significant VAT reduction in HIV lipodystrophy patients; published in multiple journals including The New England Journal of Medicine and Journal of Clinical Endocrinology & Metabolism
  • Falutz J, et al. (2007) — Phase II dose-ranging study
  • Falcone N, et al. (2023) — randomised trial of tesamorelin for cognitive function in older adults with MCI
  • Long-term safety data from open-label extension studies

The evidence for HIV-associated lipodystrophy is strong. Evidence for cognitive applications is promising but not yet sufficient for regulatory approval.

Protocols

FDA-approved dosing: 2 mg SC once daily for HIV-associated lipodystrophy. Research protocols vary by study. All non-approved use is research-only.

Tesamorelin is a prescription-only medicine (POM) in the UK. It is FDA-approved but does not hold MHRA or EMA marketing authorisation. It is not controlled under the Misuse of Drugs Act. UK access requires appropriate pharmaceutical import channels. Researchers should consult MHRA guidance.

Vendor notes

As a POM without UK marketing authorisation, tesamorelin is not available from standard UK research peptide vendors. Legitimate access requires pharmaceutical import channels. See the vendor directory for any appropriately licensed UK suppliers.

References

  1. Falutz J, Potvin D, Mamputu JC, et al. Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with safety follow-up. The Journal of Infectious Diseases. 2010;201(10):1514–1523.
  2. Falutz J, Allas S, Potvin D, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine. 2007;357(23):2359–2370.
  3. Falcone N, et al. Tesamorelin improves cognitive function in older adults with mild cognitive impairment: a randomised controlled trial. 2023.
  4. Stanley TL, Feldpausch MN, Oh J, et al. The relationship of visceral and subcutaneous adipose tissue to metabolic and cardiovascular risk in HIV infection. Journal of Clinical Endocrinology & Metabolism. 2012;97(3):E494–E502.