FDA Approved Growth Hormone Axis

Capromorelin

also known as: Entyce, Elura, CP-424,391

⚠ Veterinary use only — not approved for humans. Elanco's oral ghrelin agonist (Entyce for dogs 2016, Elura for cats 2020) — FDA-approved only for veterinary appetite stimulation. Included for completeness because it is a genuine approved ghrelin receptor agonist with significant online search volume.

⚠ Veterinary use only — not approved for humans. A small-molecule orally active ghrelin receptor (GHS-R1a) agonist originally developed by Pfizer for human GH deficiency (Phase 2 completed, discontinued for strategic reasons around 2004) and later repurposed for veterinary appetite stimulation. FDA Center for Veterinary Medicine approved capromorelin as Entyce for dogs in May 2016 (first and to date only FDA-approved appetite stimulant for dogs) and as Elura for the management of weight loss in cats with chronic kidney disease in August 2020. Marketed by Elanco. Included here for reference because it is one of the few GHS agonists with any regulatory approval and because it appears frequently in search queries adjacent to MK-677 — but it is not appropriate for human use.

Mechanism of action

Full agonist at the ghrelin receptor (GHS-R1a) in hypothalamus, pituitary somatotrophs, and vagal afferents. Produces appetite stimulation via NPY/AgRP hypothalamic circuits, modest GH release, and prokinetic effects. In dogs and cats, onset of eating behavior is typically within 1–2 hours of dosing.

Primary uses

  • ⚠ Canine appetite stimulation (Entyce — FDA-approved)
  • ⚠ Feline CKD-associated weight loss (Elura — FDA-approved)
  • Not approved for human use

Typical dosing

Not established

⚠ Veterinary dosing only (Entyce: 3 mg/kg PO once daily in dogs; Elura: 2 mg/kg PO once daily in cats). There is no human dose and capromorelin is not labeled, quality-controlled, or studied for human use in the current market.

Regulatory status

FDA Center for Veterinary Medicine approved Entyce (capromorelin oral solution 30 mg/mL) for dogs in May 2016 for appetite stimulation. Elura (capromorelin oral solution 20 mg/mL) approved August 2020 for management of weight loss in cats with chronic kidney disease. Marketed by Elanco. Original Pfizer human GHD program discontinued mid-2000s.

References

  1. [fda-pi] Entyce (capromorelin oral solution) NADA 141-457. FDA Center for Veterinary Medicine.
  2. [fda-pi] Elura (capromorelin oral solution) NADA 141-536. FDA Center for Veterinary Medicine.
  3. [pubmed] Zollers B, et al. "A prospective, randomized, masked, placebo-controlled clinical study of capromorelin in dogs with reduced appetite." J Vet Intern Med, 2016;30:1851-1857.

Related peptides

MK-677

An orally active non-peptide ghrelin receptor agonist — included here by convention because it is universally marketed alongside peptide GH secretagogues. FDA warns of heart failure risk.

Anamorelin

Ono Pharmaceutical's oral ghrelin receptor agonist (Adlumiz) — approved in Japan in 2021 for cancer cachexia in non-small-cell lung, gastric, pancreatic, and colorectal cancers; FDA issued a Complete Response Letter in 2020 and anamorelin remains unapproved in the US.

GHRP-2

A second-generation GHRP approved as a diagnostic agent in Japan, with more pronounced GH-releasing potency than GHRP-6 but a meaningful prolactin and cortisol rise at higher doses.

GHRP-6

The prototype GHRP — a hexapeptide ghrelin receptor agonist notable for pronounced hunger stimulation and less favorable cortisol/prolactin profile than newer GHRPs.
Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.