Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Hexarelin and Sermorelin — mechanism, dosing, side effects, legal status, and pricing.
Hexarelin (His-D-2MeTrp-Ala-Trp-D-Phe-Lys-NH2) is a synthetic hexapeptide growth hormone secretagogue developed by Mediolanum (Italy) in the 1990s. It is a potent ghrelin-receptor (GHSR-1a) agonist that also binds the CD36 scavenger receptor, giving it a cardioprotective signal distinct from other GHRPs. It is not FDA-approved for any indication and remains a research-only compound; its clinical development for GH deficiency and cardiac indications did not reach approval. A defining feature versus other GHRPs is rapid, pronounced tachyphylaxis with chronic daily dosing.
Sermorelin is a synthetic analog of growth hormone-releasing hormone (GHRH) consisting of the first 29 amino acids of the 44-aa native hormone — the shortest fragment that retains full biological activity. It was FDA-approved in the 1990s as Geref (EMD Serono) for diagnostic testing of pituitary GH reserve and later for pediatric idiopathic GH deficiency, but was withdrawn from the US market in 2008–2009 at the manufacturer's request for commercial reasons (not safety or efficacy). It remains on the FDA Category 1 list of bulk substances nominated for use in 503A compounding, where it is now widely prescribed off-label for adult GH insufficiency and "anti-aging" indications.
Hexarelin
Sermorelin
Category
Legal Status
Mechanism
Dose Range
Route
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Hexarelin
Sermorelin
COA corpus from Disclosed Labs — independently tested batches only.
Hexarelin
10
COAs
99.4%
Avg purity
4
Labs
Sermorelin
72
COAs
99.4%
Avg purity
10
Labs
Sermorelin is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. Hexarelin remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
Ghigo et al. (1994, PMID 8126144, JCEM) characterized hexarelin's GH-releasing activity across IV, SubQ, intranasal, and oral routes in healthy men, establishing it as a potent GH secretagogue. Rahim & Shalet (1998, PMID 10990150, Growth Horm IGF Res) demonstrated that twice-daily SubQ hexarelin in healthy elderly subjects caused ~45% attenuation of the GH AUC over 16 weeks, with partial recovery 4 weeks after discontinuation — the canonical human tachyphylaxis study. Bodart et al. (2002, PMID 11988484, Circulation Research) showed that hexarelin's cardiovascular action in perfused hearts is mediated by CD36 rather than GHSR-1a and is absent in CD36-null animals. Hexarelin has never been FDA-approved; grey-market use for body composition, recovery, or cardiac benefit is not clinically validated.
Key references
Sermorelin was FDA-approved in the 1990s as Geref for the GHRH stimulation test of pituitary function and, at higher doses, for pediatric idiopathic GHD. The principal review of pediatric Geref data is Prakash & Goa (BioDrugs 1999; PMID 18031173). In adults, Vittone et al. (Metabolism 1997; PMID 9005976) showed nightly sermorelin in healthy elderly men raised IGF-1 and modestly increased lean mass, and Khorram, Laughlin & Yen (J Clin Endocrinol Metab 1997; PMID 9141536) demonstrated that 16 weeks of nightly [Nle27]GHRH(1-29) in 19 subjects aged 55-71 restored GH/IGF-1 toward young-adult levels with small gains in lean mass and skin thickness. Walker (Clin Interv Aging 2006; PMID 18046908) reviewed the rationale for sermorelin as a more physiologic alternative to rhGH in adult GH insufficiency. EMD Serono discontinued Geref in 2008; FDA withdrew NDA approvals in 2009 and affirmed in 2013 that this was for commercial — not safety or efficacy — reasons. Unlike exogenous GH, sermorelin has not been associated with reports of acromegaly because endogenous feedback limits peak GH.
Hexarelin (Hormone) and Sermorelin (Performance) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Frequency
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing
Key references