Peptide

GHRP-6

growth hormone-releasing peptide-6

Evidence TierCWADA PROHIBITED

tuneTypical Dose

100-300 µg/kg oral or 90-100 µg IV (challenge protocols)

watchEffect Window

Minutes to hours for GH signaling. Multi-day only with short repeated testing windows in published work.

lockCompliance

WADA PROHIBITED

Overview

Clinical Summary

GHRP-6 is a ghrelin-mimetic peptide that stimulates growth hormone release and appetite. It is used for growth hormone elevation and hunger stimulation claims, largely outside validated clinical outcomes data.

Studies show reliable stimulation of growth hormone and increased appetite, which supported cachexia research interest. Evidence for meaningful changes in body composition or performance is limited without rigorous trials. Most human use in the literature is diagnostic or short-horizon endocrine physiology rather than wellness treatment. Practical benefit is uncertain and safety data for long-term nonclinical use remain limited.

GH secretagogue signaling with pituitary GH release and rapid endocrine challenge effects. Evidence strongest for acute biomarkers, weaker for durable clinical outcomes.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Acute GH release in challenge studies
  • GHRH + GHRP-6 synergy in GH stimulation
  • Rapid pharmacokinetic elimination

Secondary Outcomes

  • Potential HPA-axis activation (ACTH/cortisol in select protocols)
  • Metabolic effects context-dependent in preclinical models

Safety

Contraindications and Interactions

Contraindications

  • Unstable endocrine disease
  • Cushing spectrum without specialist supervision
  • Significant cortisol instability
  • Pregnancy
  • Breastfeeding
  • Active anti-doping restrictions

Side effects

  • Intense hunger
  • Water retention
  • Cortisol elevation
  • Joint pain

Interactions

  • GHRH/GHRH analog co-stimulation
  • Other pituitary-adrenal active agents

Avoid if

  • Unsupervised protocol use
  • Unexplained endocrine instability
  • High-competition athlete without clearance

Evidence

Study-level References

ghrp-6-SRC-001Acute endocrine challenge trial (healthy men + short-stature children, oral and dose-comparative).
Sourceopen_in_new

Bowers CY et al. The growth hormone-releasing activity of a synthetic hexapeptide in normal men and short statured children after oral administration. J Clin Endocrinol Metab. 1992;74(2):292-8. doi: 10.1210/jcem.74.2.1730807. PMID: 1730807.

Population: 5 healthy men; 9 GH-deficient children in challenge arm.

Dose protocol: Oral 100/300 µg/kg. Oral challenge linked to IV comparator.

Key findings: Oral GHRP-6 produced rapid GH elevations. 300 µg/kg showed larger GH rise and return toward baseline within ~150-180 min. Children had variable but measurable GH responses.

Paper content

Oral GHRP-6 produced rapid GH elevations; 300 µg/kg showed larger GH rise and return toward baseline within ~150–180 min; children had variable but measurable GH responses.

ghrp-6-SRC-002Ex vivo/in vitro mechanistic study on human pituitary somatotrophinomas.
Sourceopen_in_new

Lei T et al. Growth hormone releasing peptide (GHRP-6) stimulates phosphatidylinositol (PI) turnover in human pituitary somatotroph cells. J Mol Endocrinol. 1995;14(1):135-138. doi: 10.1677/jme.0.0140135. PMID: 7772238.

Population: Human cultured pituitary somatotrophinomas.

Dose protocol: Concentration-response incubation. GHRP-6-stimulated PI turnover.

Key findings: Demonstrated dose-dependent PI turnover with GH secretion increases, supporting PKC/Ca2+ signaling characteristics.

Paper content

Demonstrated dose-dependent PI turnover with GH secretion increases, supporting PKC/Ca2+ signaling characteristics.

ghrp-6-SRC-003Short-term repeated oral dosing physiological study.
Sourceopen_in_new

Ghigo E et al. Growth hormone-releasing activity of growth hormone-releasing peptide-6 is maintained after short-term oral pretreatment with the hexapeptide in normal aging. Eur J Endocrinol. 1994;131(5):499-503. doi: 10.1530/eje.0.1310499. PMID: 7952160.

Population: 7 normal elderly women, ages 65–82.

Dose protocol: 300 µg/kg oral GHRP-6 with 4-day pre-treatment.

Key findings: GH responses were maintained after 4 days and IGF-I did not materially increase.

Paper content

GH responses were maintained after 4 days and IGF-I did not materially increase.

ghrp-6-SRC-004Human endocrine challenge crossover-like comparison.
Sourceopen_in_new

Micic D et al. Growth hormone secretion after the administration of GHRP-6 or GHRH combined with GHRP-6 does not decline in late adulthood. Clin Endocrinol (Oxf). 1995;42(2):191-194. doi: 10.1111/j.1365-2265.1995.tb01861.x. PMID: 7734029.

Population: Healthy young (n=9) and late adulthood adults (n=9).

Dose protocol: GHRH 100 µg alone, GHRP-6 90 µg alone, and combination.

Key findings: Combination protocol generated larger GH responses than either stimulus alone in both age groups.

Paper content

Combination protocol generated larger GH responses than either stimulus alone in both age groups.

ghrp-6-SRC-005Clinical trial with endocrine challenge groups.
Sourceopen_in_new

Micić D et al. Growth hormone (GH) response to GH-releasing peptide-6 and GH-releasing hormone in normal-weight and overweight patients with non-insulin-dependent diabetes mellitus. Metabolism. 1999;48(4):525-530. doi: 10.1016/S0026-0495(99)90115-4. PMID: 10206449.

Population: 21 patients with NIDDM + controls.

Dose protocol: GHRP-6 90 µg, GHRH 100 µg, and combination.

Key findings: GH responses to GHRP-6 were measurable. Combined administration improved responsiveness where GHRH alone was impaired.

Paper content

GH responses to GHRP-6 were measurable; combined administration improved responsiveness where GHRH alone was impaired.

ghrp-6-SRC-006Pharmacokinetic study.
Sourceopen_in_new

Cabrales A et al. Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers. Eur J Pharm Sci. 2013;48(1-2):40-46. doi: 10.1016/j.ejps.2012.10.006. PMID: 23099431.

Population: Nine male healthy volunteers.

Dose protocol: IV bolus 100, 200, 400 µg/kg with LC-MS quantification.

Key findings: Bi-exponential disposition, average t1/2 7.6 ± 1.9 min and t1/2 elimination 2.5 ± 1.1 h.

Paper content

Bi-exponential disposition, average t1/2 7.6 ± 1.9 min and t1/2 elimination 2.5 ± 1.1 h.

ghrp-6-SRC-007Comparative diagnostic test study.
Sourceopen_in_new

Alaioubi B et al. Diagnosis of adrenal insufficiency using the GHRP-6 Test: comparison with the insulin tolerance test in patients with hypothalamic-pituitary-adrenal disease. Horm Metab Res. 2010;42(3):198-203. doi: 10.1055/s-0029-1243184. PMID: 19946832.

Population: 49 patients with suspected HPA-axis dysfunction + 20 controls.

Dose protocol: GHRP-6 1 µg/kg IV with 90-min cortisol monitoring.

Key findings: GHRP-6 test showed cortisol separation between AI and sufficient groups. No detectable side effects reported in this cohort.

Paper content

GHRP-6 test showed cortisol separation between AI and sufficient groups; no detectable side effects reported in this cohort.

ghrp-6-SRC-008Clinical endocrine comparison trial.
Sourceopen_in_new

Oliveira JHA et al. GHRP-6 is able to stimulate cortisol and ACTH release in patients with Cushing's disease: comparison with DDAVP. J Endocrinol Invest. 2003;26(3):230-235. doi: 10.1007/BF03345162. PMID: 12809173.

Population: Patients with Cushing's disease and healthy comparators.

Dose protocol: GHRP-6 2 µg/kg IV with endocrine sampling.

Key findings: GHRP-6 increased ACTH and cortisol responses comparable to DDAVP in disease context.

Paper content

GHRP-6 increased ACTH and cortisol responses comparable to DDAVP in disease context.

ghrp-6-SRC-009Policy document / regulatory source.
Sourceopen_in_new

World Anti-Doping Agency (WADA) prohibited class context: S2.2.4 includes GH-releasing peptides (examples include GHRP-6) and growth hormone secretagogues under the peptide hormone class; access via WADA prohibited-list pages and updates effective in annual cycles.

Population: All athletes governed by WADA/affiliated anti-doping code.

Dose protocol: Not applicable.

Key findings: Prohibited-class categorization implies high compliance risk for use in competition contexts.

Paper content

Prohibited-class categorization implies high compliance risk for use in competition contexts.

ghrp-6-SRC-010Enforcement communication case record.
Sourceopen_in_new

USADA sanction text for Chad Mendes indicates positive GHRP-6 finding under UFC anti-doping policy adopting WADA prohibited-list framework and states GHRPs are Non-Specified Substances on WADA class.

Population: Athlete governance context.

Dose protocol: Not applicable

Key findings: Demonstrates practical enforcement mapping for GHRP-6 under WADA-aligned rules.

Paper content

Demonstrates practical enforcement mapping for GHRP-6 under WADA-aligned rules.

ghrp-6-SRC-011Preclinical rodent mechanistic study.
Sourceopen_in_new

Granado M et al. The positive effects of growth hormone-releasing peptide-6 on weight gain and fat mass accrual depend on insulin/glucose status. Endocrinology. 2010;151(5):2008-18. doi: 10.1210/en.2009-1394. PMID: 20219977.

Population: Streptozotocin-induced diabetic rats.

Dose protocol: Daily GHRP-6 with/without insulin over 8 weeks.

Key findings: Demonstrates glucose-insulin context effects on fat accrual when combined with insulin. Limited direct human extrapolation.

Paper content

Demonstrates glucose-insulin context effects on fat accrual when combined with insulin; limited direct human extrapolation.

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