Sermorelin

See our Evidence Standards for how we grade the research below.

What It Is

Sermorelin (sermorelin acetate, GRF(1-29)-NH2) is a synthetic peptide reproducing the first 29 amino acids of endogenous growth-hormone-releasing hormone (GHRH), the shortest fragment of the native 44-amino-acid hormone shown to retain full biological activity. It binds the GHRH receptor on pituitary somatotrophs, stimulating GH release through the same receptor and pathway that endogenous GHRH uses, which is why GHRH analogs are generally considered more physiologic than direct ghrelin-mimetic secretagogues: the pituitary's own feedback loop (via somatostatin) remains intact, capping the response rather than driving GH release independent of that brake.

Sermorelin was previously FDA-approved (as Geref) for diagnostic testing of GH reserve and for treatment of pediatric growth hormone deficiency, before the manufacturer discontinued it in 2008 for commercial reasons unrelated to safety. It is not currently an FDA-approved product; where it is used today, it is compounded.

A note on sermorelin versus related analogs: Several closely related GHRH (1-29) analogs exist with small structural modifications intended to improve stability or potency (for example, an analog with norleucine substituted for methionine at position 27, often denoted [Nle27]-GHRH). These are chemically distinct from unmodified sermorelin, even though some commercial literature uses the names interchangeably. Below, we identify which studies used unmodified sermorelin and which used a modified analog, since conflating them would overstate what's actually been shown for the specific molecule.

The Evidence

Corpas E, Harman SM, Piñeyro MA, Roberson R, Blackman MR. "Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men." Journal of Clinical Endocrinology & Metabolism. 1992 Aug;75(2):530-5. PMID: 1379256. Randomized crossover trial using unmodified GHRH (1-29), the sermorelin molecule. 10 healthy nonobese old men (mean age 68) and 9 young men (mean age 26) as a reference group. Old men received both low-dose (0.5 mg) and high-dose (1 mg) GHRH-(1-29) subcutaneously twice daily for 14 days each, in random order with a washout period between. At baseline, old men had lower peak GH duration and IGF-1 than young men. High-dose GHRH treatment produced dose-related increases in GH secretion measures and IGF-1, and at the high dose these parameters were no longer significantly different from the young men's baseline values.

Design: Small human crossover trial Endpoint: Mechanism / surrogate (GH, IGF-1 levels)

Vittone J, Blackman MR, Busby-Whitehead J, et al. "Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men." Metabolism. 1997 Jan;46(1):89-96. PMID: 9005976. Unmodified GHRH (1-29). 11 healthy, ambulatory, nonobese men aged 64-76 with low baseline IGF-1 self-administered nightly subcutaneous GHRH 2 mg for 6 weeks at home. The trial found no significant change in body weight, BMI, waist-to-hip ratio, DEXA-measured muscle or fat mass, muscle histology, or glucose/insulin/GH response to oral glucose tolerance testing. GHRH altered the relationship between muscle bioenergetic measures and strength in a way the authors interpreted as consistent with reduced reliance on anaerobic metabolism during exercise, but the trial's own conclusion was that single nightly dosing was less effective than multiple daily dosing for GH/IGF-1-mediated effects. No significant adverse effects were observed.

Design: Small human trial Endpoint: Mixed (body composition/metabolic outcome: null; muscle bioenergetics: mechanism)

Khorram O, Laughlin GA, Yen SSC. "Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women." Journal of Clinical Endocrinology & Metabolism. 1997 May;82(5):1472-9. PMID: 9141536. Single-blind, randomized, placebo-controlled, 5-month trial. 10 women and 9 men, ages 55-71, self-injected placebo nightly for 4 weeks, then the modified GHRH analog (10 mcg/kg SC nightly) for 16 weeks.

This trial used the [Nle27]-modified GHRH analog, not unmodified sermorelin. We include it because it is one of the few controlled, months-long human trials in this class, but the findings below apply to the modified analog, not necessarily to unmodified sermorelin.

Compared with placebo, the analog significantly increased nocturnal GH and, within 2 weeks, IGF-1 and IGFBP-3, with effects declining back toward baseline by 16 weeks. Blood pressure and body weight were unaffected. Skin thickness increased in both sexes. Lean body mass increased in men only, with no other body-composition changes in either sex. Insulin sensitivity improved in men only. General wellbeing and libido improved in men only; sleep quality was unaffected in either sex. The only adverse effect was transient hyperlipidemia that resolved by study end.

Design: Small human RCT (modified analog, not sermorelin itself) Endpoint: Mixed (lean mass, insulin sensitivity, wellbeing = outcome; GH/IGF-1 = surrogate)

What's Reported in Practice

Anecdotal / clinical experience, not yet trial-tested

In clinical practice, sermorelin is one of the more frequently reported peptides for improved sleep quality, gradual improvements in body composition, and a subjective sense of better recovery and energy over months of use. These reports line up with what we'd expect mechanistically from restoring more physiologic, pulsatile GH release, and we think they're a genuine signal worth further study, not just noise. They have not been demonstrated for unmodified sermorelin in a controlled human trial at the doses and durations typically used today, so we present them as reported experience rather than established evidence.

What the Research Doesn't Yet Show

This is where we're most eager to see more research investment, not a mark against the compound. The controlled human evidence for unmodified sermorelin itself is limited to small, short-duration trials (14 days to 6 weeks) using surrogate endpoints (GH and IGF-1 levels) or finding no change in body composition at the dose and duration tested. The longest-duration controlled trial in this class (5 months, with real body-composition and quality-of-life outcomes) used a structurally modified analog, not sermorelin itself, and found sex-specific effects (benefits concentrated in men, not women) that have not, to our knowledge, been directly tested for unmodified sermorelin. We didn't identify a long-duration, placebo-controlled trial of unmodified sermorelin measuring body composition, strength, or quality-of-life outcomes directly, which is exactly the gap a well-funded outcomes trial could close, especially given how consistently patients report benefit in practice. Whether the results seen with the modified analog would replicate with unmodified sermorelin, at the doses and durations used in current clinical practice, remains an open and answerable question.

Compounded, not FDA-approved for this indication. Sourcing and availability are discussed at your visit.

Next Step

This page covers mechanism and evidence. Dosing, cycling, and whether this is appropriate for you are individual clinical decisions made with your provider.

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