Capromorelin

Overview

Capromorelin is a non-peptide, orally active pyrazolinone-piperidine dipeptide-mimetic that functions as a growth hormone secretagogue receptor 1a (GHS-R1a) agonist, mimicking the endogenous hormone ghrelin. It is NOT approved for human use anywhere; a Pfizer Phase II trial in 395 older adults showed positive signals for lean body mass, body weight, and physical function but was terminated early and never advanced to approval. Capromorelin is FDA-approved as a veterinary drug (Entyce for dogs, Elura for cats) and is explicitly named on the WADA Prohibited List under S2 (growth hormone secretagogues), prohibited at all times in competitive sport.

Mechanism of Action

Capromorelin is a non-peptide agonist of the growth hormone secretagogue receptor 1a (GHS-R1a), the endogenous ghrelin receptor, with a binding affinity (Ki) of 7 nM at human GHS-R1a and an EC50 of 3 nM in rat pituicytes. It mimics ghrelin in the hypothalamus and pituitary to stimulate pulsatile growth hormone release and, via GHS-R1a-expressing neurons, increases appetite and food intake. All binding and potency data derive from in vitro and animal pharmacology studies, not human receptor-occupancy studies.

Research Summary

Capromorelin has human clinical trial data but is not an approved human drug. A Pfizer-sponsored Phase II trial randomized 395 adults aged 65–84 at risk of functional decline to oral capromorelin or placebo for up to 2 years (315 completed 6 months; 284 completed 12 months). The trial reported increased lean body mass (+1.4 vs 0.3 kg, P=0.001), body weight (+1.4 kg, P=0.006), improved tandem walk (P=0.02), and improved stair climb (P=0.04), concluding capromorelin "may improve body composition and physical function." The study was terminated early according to predetermined treatment effect criteria; no human product was ever approved. Preclinical studies in rats showed an ED50 <0.05 mg/kg IV for plasma GH elevation; in healthy Beagle dogs, oral capromorelin increased food consumption and body weight in a 4-day randomized, masked, placebo-controlled trial. In healthy cats, capromorelin altered glucose-metabolism parameters. In broiler chickens, it increased feed intake and body-weight gain.

Vendors selling Capromorelin

Scored vendors carrying Capromorelin, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Reported Side Effects

• Fatigue and insomnia (Phase II trial)
• Small increases in fasting glucose, HbA1c, and insulin resistance (Phase II trial)
• Vomiting and hypersalivation (veterinary field study, cats)
• Altered glucose metabolism (preclinical, cats)
• WADA-prohibited; detectable in urine after incidental exposure

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Research References

• Capromorelin — PubChem Compound Summary (CID 216208).
• Pyrazolinone-piperidine dipeptide growth hormone secretagogues (GHSs). Discovery of capromorelin. 2003. PMID 12538023.
• Effects of an oral growth hormone secretagogue in older adults. 2009. PMID 19174493.
• Capromorelin oral solution (ENTYCE) increases food consumption and body weight in healthy adult Beagle dogs. 2017.

Frequently asked questions

Where can researchers source Capromorelin?

1 vendor with Disclosed Labs trust grades currently list Capromorelin, including Kimera Chems. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/capromorelin.

How does Capromorelin work?

Capromorelin is a non-peptide agonist of the growth hormone secretagogue receptor 1a (GHS-R1a), the endogenous ghrelin receptor, with a binding affinity (Ki) of 7 nM at human GHS-R1a and an EC50 of 3 nM in rat pituicytes. It mimics ghrelin in the hypothalamus and pituitary to stimulate pulsatile growth hormone release and, via GHS-R1a-expressing neurons, increases appetite and food intake. All binding and potency data derive from in vitro and animal pharmacology studies, not human receptor-occupancy studies.

What does the research say about Capromorelin?

Capromorelin has human clinical trial data but is not an approved human drug. A Pfizer-sponsored Phase II trial randomized 395 adults aged 65–84 at risk of functional decline to oral capromorelin or placebo for up to 2 years (315 completed 6 months; 284 completed 12 months). The trial reported increased lean body mass (+1.4 vs 0.3 kg, P=0.001), body weight (+1.4 kg, P=0.006), improved tandem walk (P=0.02), and improved stair climb (P=0.04), concluding capromorelin "may improve body composition and physical function." The study was terminated early according to predetermined treatment effect criteria; no human product was ever approved. Preclinical studies in rats showed an ED50 <0.05 mg/kg IV for plasma GH elevation; in healthy Beagle dogs, oral capromorelin increased food consumption and body weight in a 4-day randomized, masked, placebo-controlled trial. In healthy cats, capromorelin altered glucose-metabolism parameters. In broiler chickens, it increased feed intake and body-weight gain.