Claimed effect · Hexarelin

Does Hexarelin help with growth hormone release?

C
Grade C — weak human evidenceMultiple acute studies + 1 chronic study · effect size: moderate
Short answerWeak human evidence. Multiple acute studies + 1 chronic study: enough to be interesting, not enough to count on. Where an effect is seen it is a moderate effect. Acute GH release after hexarelin is large and well established. Over 16 weeks of twice-daily dosing the response attenuated and then recovered after stopping — a tolerance effect typical of the class.

What the studies show

Acute GH release after hexarelin is large and well established. Over 16 weeks of twice-daily dosing the response attenuated and then recovered after stopping — a tolerance effect typical of the class.

“chronic hexarelin therapy results in a partial and reversible attenuation of the GH response to hexarelin.”

Verbatim, from the abstractRahim A, et al. Growth hormone status during long-term hexarelin therapy. J Clin Endocrinol Metab, 1998;83:1644–1649

A few small or poorly-controlled human studies. Enough to be interesting; not enough to count on. Most of what gets called “clinically proven” online lives here.

  1. 1
    Rahim A, et al. Growth hormone status during long-term hexarelin therapy.J Clin Endocrinol Metab, 1998;83:1644–164916 weeks; GH response attenuates, IGF-1 and body composition unchanged.

In context

Hexarelin is a synthetic six-amino-acid growth-hormone-releasing peptide. Single doses cause a strong, well-documented growth-hormone spike in humans, but the one study of continued use showed the response fades within weeks and that IGF-1 and body composition did not meaningfully change. It was never developed into an approved medicine, and the muscle, fat-loss and cardiac claims made for it have no controlled human evidence.

Hexarelin is not approved. Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is Hexarelin proven to help with growth hormone release?
No. The human evidence is weak (Multiple acute studies + 1 chronic study); LYO grades it C.
What studies are behind the grade?
Acute GH release after hexarelin is large and well established. Over 16 weeks of twice-daily dosing the response attenuated and then recovered after stopping — a tolerance effect typical of the class.
Is Hexarelin approved for this?
No. Hexarelin is not approved; it is not an approved medicine for any indication in the jurisdictions LYO covers.

Other outcomes for Hexarelin

Written and maintained by LYO Research — how pages are written and checked. Reviewed 3 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →