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approvedMuscle & Performance

Capromorelin

Also known as: Entyce, CP-424391

Capromorelin is an oral ghrelin receptor agonist (growth hormone secretagogue) that is FDA-approved in veterinary medicine as Entyce for appetite stimulation in dogs. It is the only ghrelin mimetic commercially available in any species. In human clinical trials, it increased growth hormone secretion and improved lean body mass in elderly subjects, though human development was discontinued. Its veterinary success validates the ghrelin pathway for appetite and metabolic regulation.

4 cited references·5 researched benefits

Quick Answer

Capromorelin (Entyce) is an oral ghrelin receptor agonist FDA-approved for veterinary use to stimulate appetite in dogs. While human clinical trials showed promising GH secretion increases and lean mass improvements in elderly subjects, human development was discontinued. It remains the only commercially marketed ghrelin receptor agonist in any species, validating the ghrelin/GHS-R1a pathway for appetite stimulation and metabolic regulation.

Key Facts

Mechanism
Capromorelin is a non-peptide, orally bioavailable agonist of the growth hormone secretagogue receptor 1a (GHS-R1a). Binding GHS-R1a on hypothalamic arcuate nucleus neurons activates neuropeptide Y/AgRP orexigenic signaling, increasing appetite and food intake. Simultaneously, GHS-R1a activation on anterior pituitary somatotrophs stimulates growth hormone release via Gq-coupled calcium signaling. In dogs, this dual appetite-GH effect effectively addresses the anorexia and weight loss associated with chronic illness.
Research Status
approved
Half-Life
~2–4 hours
Primary Use
Muscle & Performance
Table of Contents

Benefits

  • Appetite stimulation — significant increase in food intake demonstrated in both canine and human studiesstrong
  • Growth hormone secretion — dose-dependent GH release in clinical studiesstrong
  • Lean body mass improvement — human phase 2 trials showed increased lean mass in elderly subjects over 12 monthsmoderate
  • Oral bioavailability — practical oral dosing unlike injectable GH secretagoguesstrong
  • Validated safety profile — extensive veterinary use since 2016 provides long-term safety datamoderate

Dosage Protocols

RouteDosage RangeFrequencyNotes
Oral solution (veterinary — Entyce)3 mg/kg body weightOnce dailyFDA-approved for dogs only. Administered as oral solution (30 mg/mL) for appetite stimulation in dogs with decreased appetite. Not for human use.
Oral (human clinical trials — discontinued)5–20 mgOnce dailyPhase 2 human trials tested oral doses for age-related GH decline and sarcopenia. Human development was discontinued despite positive efficacy signals.

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Diarrhea — reported in both canine and human studies (10–15%)common
  • Polydipsia — increased thirst observed in veterinary usecommon
  • Transient hyperglycemia — GH-mediated insulin resistance may elevate blood glucoserare
  • Vomiting — occasional GI effects in some subjectscommon
  • Fluid retention — mild edema related to GH elevationrare

Frequently Asked Questions

Why is capromorelin available for dogs but not humans?
Capromorelin was initially developed for human use by Pfizer, but human development was discontinued due to strategic portfolio decisions rather than safety or efficacy concerns. The veterinary division (later Aratana Therapeutics, now Elanco) continued development for canine appetite stimulation, achieving FDA approval in 2016. The regulatory pathway for veterinary drugs is separate from human drugs. If a pharmaceutical company chose to resume human development, new clinical trials would be required.
How does capromorelin compare to MK-677?
Both are oral ghrelin receptor agonists, but MK-677 (ibutamoren) has a much longer half-life (~24 hours vs ~2–4 hours for capromorelin), producing more sustained GH elevation. MK-677 has more extensive human clinical trial data but is not approved for any indication. Capromorelin is the only one with regulatory approval (veterinary). For research purposes, MK-677's longer duration of action and more extensive human data make it more commonly studied.
Could capromorelin help with human sarcopenia?
Human phase 2 data showed that capromorelin increased lean body mass and improved physical function in elderly subjects with functional limitations. Sarcopenia (age-related muscle loss) is a condition where ghrelin pathway activation could theoretically help through dual appetite stimulation and GH/IGF-1 axis engagement. However, without a sponsor pursuing human FDA approval, capromorelin remains unavailable for human use. Other approaches to sarcopenia (resistance exercise, protein supplementation) remain the standard of care.
Is it safe to use veterinary capromorelin in humans?
Using veterinary medications in humans is illegal, dangerous, and strongly discouraged. Veterinary Entyce is formulated as a flavored oral solution for dogs with different dosing, excipients, and quality controls than required for human pharmaceutical products. The concentration, additives, and manufacturing standards differ from human drug requirements. Anyone interested in ghrelin pathway therapy should discuss options with their physician.
What did the human clinical trials of capromorelin show?
A 12-month phase 2 trial in elderly subjects (65+ years) with functional limitations showed: significant increases in GH and IGF-1 levels, improved lean body mass (+1.4 kg vs placebo), trends toward improved stair climbing and tandem walking performance, and acceptable safety profile. These results suggested potential benefit for age-related functional decline, but the sponsor chose not to pursue phase 3 development for commercial strategy reasons.

References

  1. 1
    Capromorelin increases food consumption and body weight when administered for 12 months to healthy adult dogs(2017)PubMed ↗
  2. 2
    Oral ghrelin receptor agonist capromorelin increases lean body mass in healthy older adults: a randomized trial(2008)PubMed ↗
  3. 3
    Growth hormone secretagogues: clinical pharmacology and therapeutic potential(1999)PubMed ↗
  4. 4
    Ghrelin and synthetic GH secretagogues: pharmacological approaches to appetite and metabolism(2013)PubMed ↗

Latest Research

Last updated: 2026-02-19