Capromorelin

Not a peptide. Capromorelin is an orally active small molecule (a pyrazolinone-piperidine peptidomimetic developed from the Merck/Pfizer growth hormone secretagogue programmes). It is included because it is a ghrelin receptor agonist discussed alongside GHRPs and ipamorelin, and because the veterinary products are widely available and sometimes misused by people. The same evidence standards apply.

Entyce (dogs), Elura (cats), CP-424,391

Growth hormone axis

Awaiting medical reviewEN ES DE FR PT ZH+ Follow for updates

Note on this profile. Capromorelin is an approved veterinary medicine (FDA, 2016 for dogs; 2020 for cats) and is not approved for humans anywhere. Veterinary formulations are made and dosed for animals.

Summary

Class: Non-peptide small-molecule ghrelin receptor (GHS-R1a) agonist; oral
Mechanism: Mimics ghrelin to stimulate appetite and release growth hormone and IGF-1
Routes studied: Oral (humans, dogs, cats)
Dose range reported: Veterinary labels: dogs 3 mg/kg once daily (Entyce, 30 mg/mL oral solution); cats 2 mg/kg once daily (Elura, 20 mg/mL oral solution). Human trial (older adults): arms of roughly 3–10 mg once or twice daily, i.e. about 3–20 mg/day †. No human dose is approved; community use of veterinary solution is reported at a few mg to tens of mg per day
Half-life: Dogs: ~1–2 hours, with GH peak within an hour and IGF-1 elevation lasting a day; humans: short, roughly 2–3 hours †
Storage: Veterinary solutions: room temperature as labelled, discard after the labelled period once opened
Regulatory status: Veterinary-approved (US and some other countries); not approved for human use anywhere

Doses are as reported in studies or by the community — never recommendations.

1What it is

Capromorelin came out of Pfizer's growth hormone programme in the late 1990s as an oral alternative to injected GH for frailty in older people. A two-year human trial was started and stopped early when the sponsor judged that improvements in body composition were not matched by convincing functional benefit. The compound was later licensed to a veterinary company (Aratana, now part of Elanco) and became Entyce, the first FDA-approved appetite stimulant for dogs (2016), and Elura, approved for managing weight loss in cats with chronic kidney disease (2020).

It is on this site because the veterinary oral solutions are easy to obtain and have been used by people as an oral GH secretagogue, in the same way MK-677 / ibutamoren is. The human evidence consists essentially of one trial; the animal evidence is good, but it is about dogs and cats.

2How it's thought to work

Capromorelin activates in the hypothalamus (appetite, via NPY/AgRP neurons) and pituitary (GH release), with secondary IGF-1 elevation from the liver. In dogs, single doses produce a GH peak within about an hour and sustained IGF-1 increases with daily dosing; food intake rises within a day. In humans, the same mechanism produced small increases in IGF-1 and lean mass over months, with the appetite effect being clinically obvious.

An oral ghrelin receptor agonist licensed as an appetite stimulant in dogs and cats. The same receptor, the same growth hormone pulse.Schematic — not to scale

3What the research shows

Graded A (one trial, stopped early)

Older adults

A two-year randomised, double-blind, placebo-controlled trial in 395 healthy adults aged 65–84 with mild functional limitation tested several oral capromorelin regimens. Over 6–12 months, lean body mass increased by about 1.4 kg versus placebo, and two of several function tests improved (tandem walk at 6 months, stair climb at 12 months); strength and other function measures did not change significantly. The trial was stopped at a pre-planned interim analysis because efficacy criteria were not met (White 2009, JCEM). IGF-1 rose; fasting glucose and HbA1c rose slightly; fatigue, insomnia and increased appetite were more common. [1]

Graded A (veterinary)

Appetite in dogs

A randomised, masked, placebo-controlled field study in 177 dogs with reduced appetite reported owner-assessed appetite improvement in ~69% on capromorelin versus ~45% on placebo over 4 days, with increased body weight (Zollers 2017, J Vet Pharmacol Ther). Pharmacology studies in healthy beagles showed dose-dependent GH and IGF-1 increases and weight gain with prolonged dosing (Zollers 2017, Vet Med Sci; 12-month safety study). [2][3]

Graded A (veterinary)

Weight loss in cats with chronic kidney disease

Placebo-controlled field studies supported the Elura approval, showing body weight stabilisation or gain over 8 weeks (Wofford 2018, J Vet Intern Med — pharmacology in healthy cats; Elura freedom-of-information summary for the field trial). [4]

Body composition in healthy young adults, recovery, sleep

No human studies. Community use extrapolates from the older-adult trial and from MK-677.

4Reported side effects and interactions

Literature-reported

Literature (human). increased appetite, fatigue, insomnia, increased fasting glucose and HbA1c, oedema; discontinuations for adverse events were somewhat higher than placebo in the older-adult trial.

Literature (veterinary). dogs — diarrhoea, vomiting, hypersalivation, polydipsia, lethargy, flatulence; cats — vomiting, hypersalivation, lethargy, inappetence paradoxically in some, and increases in liver enzymes and blood glucose noted in safety studies. The dog label notes caution with hepatic or renal impairment. Elanco reported rare but serious events including bradycardia and hypotension in cats.

Community-reported

Community-reported (human use of veterinary product). marked hunger, lethargy, water retention, vivid dreams, raised fasting glucose; dosing uncertainty from using a liquid formulated for animals by weight.

Theoretical. GH/IGF-1 class concerns — insulin resistance, fluid retention, caution with active malignancy; cardiac conduction effects seen with related compounds (anamorelin) have not been characterised in humans for capromorelin. Veterinary excipients and flavourings are not evaluated for human use.

Interactions. metabolised by CYP3A4 in dogs with potential for inhibitor interactions; glucose-lowering medicines may need adjustment. Human interaction data are minimal.

Markers researchers commonly monitor

Based on the human trial and GH-axis physiology:

Marker	Why it's watched
IGF-1	rose in the trial; the marker of GH-axis effect and over-exposure.
Fasting glucose, fasting insulin, HbA1c	both glucose and HbA1c rose in the human trial; the key safety markers.
Body weight and appetite log	appetite stimulation is the main and most predictable effect.
Blood pressure and oedema	fluid retention is a class effect.
Liver enzymes	increases were noted in feline safety studies; no human signal, but a cheap baseline.
Sleep quality	insomnia was reported in the human trial, unlike the sleep improvement often claimed for MK-677.
Lipid panel	GH shifts lipids.

Free for everyone. Safety information is never behind a paywall.

5Formulation and handling

Veterinary oral solutions (30 mg/mL for dogs, 20 mg/mL for cats) are flavoured liquids measured by syringe and dosed by body weight; they are made to veterinary, not human, pharmaceutical standards and their excipients are not assessed for people. Store at room temperature; discard after the labelled in-use period. Research-grade powder exists but is uncommon. No calculator link is offered.

6Commonly studied alongside

In the human trial, nothing. Among research compounds, MK-677 / ibutamoren (the obvious comparator — same class, same oral route, far more human data), anamorelin, ipamorelin and the GHRPs, macimorelin. In veterinary practice, mirtazapine and maropitant are the usual comparators or co-treatments.

Informational cross-links. Not stack recommendations.

7Regulatory status by region

Region	Status (checked —)
United States	FDA-approved for dogs (Entyce, 2016) and cats (Elura, 2020) as prescription veterinary medicines; not approved for humans; not a compounding-list substance
European Union	Entyce authorised for dogs by the EMA (2021) †; no human authorisation
United Kingdom	Veterinary authorisation for dogs †; no human licence
Australia	Veterinary approval status †; no human approval
South Africa	Not registered for humans †
Sport	Prohibited by WADA (S2 — capromorelin is named as an example of a GH secretagogue)

8Open questions

Whether any oral GH improves physical function in older adults; capromorelin's trial, like MK-677's, found body-composition change without clear function change.
Human pharmacokinetics and safety at repeated doses — one trial is not a safety database.
The actual content and consistency of veterinary solutions used by people.

9References

1White HK et al. (2009). Effects of an oral growth hormone secretagogue in older adults. J Clin Endocrinol Metab. PubMed · DOI
2Zollers B et al. (2017). A prospective, randomized, masked, placebo-controlled clinical study of capromorelin in dogs with reduced appetite. J Vet Intern Med [verify journal]. PubMed · DOI
3Zollers B et al. (2017). Capromorelin increases food consumption, body weight, growth hormone, and sustained insulin-like growth factor 1 concentrations when administered to healthy adult Beagle dogs. J Vet Pharmacol Ther. PubMed · DOI
4Wofford JA et al. (2018). Evaluation of the safety of daily administration of capromorelin in cats. J Vet Pharmacol Ther. PubMed · DOI
5Rhodes L et al. (2018). Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs. Vet Med Sci. PubMed · DOI
6US FDA Center for Veterinary Medicine. Freedom of Information summaries: Entyce (NADA 141-457) and Elura (NADA 141-536). PubMed
7Carpino PA et al. (2003). Pyrazolinone-piperidine dipeptide growth hormone secretagogues (GHSs): discovery of capromorelin. Bioorg Med Chem. PubMed · DOI

References are being resolved to PubMed/DOI identifiers; links search PubMed for the citation until then.

† Being confirmed by our reviewers against current sources.

10Community

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Self-reported side effects Phase 2

Not enough data yet. 0 of the 50 members needed have logged this compound for 4+ weeks. We don't show anything below 50, so no one can be identified.

11Page history

26 Oct 2026Profile published — awaiting medical review

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