The short version
Growth hormone (somatropin) is the hormone. You inject it, and it acts directly — on muscle, fat, bone, and on blood sugar — regardless of what your body wanted that day.
Sermorelin is the signal. It is a copy of the first 29 amino acids of growth-hormone-releasing hormone. It asks your pituitary to release growth hormone, and your pituitary decides how much, held in check by somatostatin — the body’s own brake (Walker 2006).
That mechanical difference drives three practical differences: the law, the evidence, and the side effects.
1. The law treats them differently
Human growth hormone has its own federal statute. Under 21 U.S.C. § 333(e), “whoever knowingly distributes, or possesses with intent to distribute, human growth hormone for any use in humans other than the treatment of a disease or other recognized medical condition, where such use has been authorized by the Secretary of Health and Human Services … is guilty of an offense punishable by not more than 5 years in prison” (21 U.S.C. § 333(e)). Adult growth-hormone deficiency is a recognized condition; “anti-aging,” “optimization” and “performance” are not.
Sermorelin has no such statute. Its brand product, Geref, was FDA-approved in 1997 and later discontinued for reasons the Federal Register notice says were “not … safety or effectiveness” (Drugs@FDA, NDA 020443). Today it is a compounded medication prescribed for an individual patient — and compounded medications are not FDA-approved as a category.
This is the first reason we do not offer injected growth hormone: for the people who come to us, it would be illegal to prescribe.
2. The evidence looks different
Growth hormone in healthy older adults has been studied far more — and the results are why the enthusiasm cooled. The trial that started it reported a 8.8% increase in lean body mass and a 14.4% decrease in fat mass over six months in 12 treated men aged 61–81 (Rudman 1990). Seventeen years later, a systematic review pooled 31 studies and 220 treated participants: fat mass fell by about 2.1 kg and lean mass rose by about 2.1 kg, with no clear gain in strength or function — and the authors concluded growth hormone “cannot be recommended as an antiaging therapy” (Liu 2007, Annals of Internal Medicine).
Sermorelin’s evidence is smaller and points elsewhere. A six-week trial found strength gains on some measures but no change in body composition or IGF-1 (Vittone 1997); six-month and twenty-week trials of GHRH analogs found improved cognition (Vitiello 2006; Baker 2012). No sermorelin trial has shown the body-composition shift that growth hormone produces. If someone sells sermorelin as “HGH results without HGH,” the trials do not support it.
3. The side effects look different
The pooled growth-hormone data are specific: treated participants were “significantly more likely to experience soft tissue edema, arthralgias, carpal tunnel syndrome, and gynecomastia,” and “somewhat more likely to experience the onset of diabetes mellitus” (Liu 2007). A 2025 review puts the ranges at fluid retention in 11–100% of patients, carpal tunnel in 7–50%, joint pain in 14–77% (Fernández-Garza 2025).
Those effects come from sustained, supraphysiologic growth-hormone exposure. Sermorelin’s proposed advantage — unproven as an outcome, but mechanistically sound — is that pituitary release stays pulsed and feedback-limited, so, in the words of the 2006 review, “overdoses of endogenous hGH are difficult if not impossible to achieve” (Walker 2006). The small sermorelin trials reported no significant adverse effects. That is reassuring but not proof; a six-week, eleven-person study cannot rule out what a 220-person pooled analysis found.
The comparison in one table
| Growth hormone (somatropin) | Sermorelin | |
|---|---|---|
| What it is | The hormone itself | GHRH 1-29, the releasing signal |
| Feedback control | Bypassed | Preserved (somatostatin brake) |
| Legal for “anti-aging”? | No — 21 U.S.C. § 333(e) | Compounded on prescription; not FDA-approved |
| Body composition in trials | ~2 kg fat down, ~2 kg lean up (pooled) | No change shown |
| Cognition in trials | Not the focus | Improved in two trials of GHRH analogs |
| Edema / joint pain / carpal tunnel | Significantly increased | Not reported in small trials |
| Long-term safety data | Concerning signals (diabetes onset) | None — no long-term trials |
What this means for you
If you have true adult growth-hormone deficiency — a diagnosis made with stimulation testing by an endocrinologist — growth hormone is an approved, legal treatment and you should pursue it through that pathway. We are not that pathway.
If you are a healthy adult hoping to feel and perform better, injected growth hormone is neither legal for that purpose nor recommended by the evidence. Sermorelin is a legal, provider-evaluated option with modest evidence and a cleaner mechanism — and the honest expectation is modest, measured, and reviewed with your provider at six months. Our what-to-expect guide lays out that timeline.
Compounded medications are not FDA-approved. This article is education, not medical advice, and does not establish a provider–patient relationship.
Sources: 21 U.S.C. § 333(e) · Drugs@FDA — Geref NDA 020443 · Walker RF, Clin Interv Aging 2006 (PMC2699646) · Rudman D et al., N Engl J Med 1990 (PMID 2355952) · Liu H et al., Ann Intern Med 2007 (PMID 17227934) · Vittone J et al., Metabolism 1997 (PMID 9005976) · Vitiello MV et al., Neurobiol Aging 2006 (PMID 16399214) · Baker LD et al., Arch Neurol 2012 (PMID 22869065) · Fernández-Garza LE et al., Front Aging 2025 (PMC12009952)