This page describes published research and public regulatory records. It is not medical advice. SoluneFit does not sell, supply, or recommend any compound. The SoluneFit app includes a private, on-device tracker for people who want a record of what they and their clinician have already decided — the app neither suggests compounds nor doses.
Also known as: growth hormone releasing peptide-6, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2.
Regulatory status
Not approved. In 503A category 3 (nominated without adequate support) [3], so not compoundable from bulk under 503A; in 503B category 2 (significant safety risks: cortisol effects, higher blood glucose from reduced insulin sensitivity) since 29 Sep 2023 [4]. FDA cited GHRP-6 in a 2019 compounding warning letter [5].
What it is
Growth hormone-releasing peptide; ghrelin-receptor (GHS-R1a) agonist; synthetic hexapeptide.
One of the first synthetic GH-releasing peptides, described by Bowers in 1984, and the template for later ghrelin-receptor agonists. It releases growth hormone in humans and also raises cortisol and prolactin at higher doses. It has never been approved anywhere as a medicine in the sources found.
What the published research shows
Small acute human studies (e.g. 18 healthy men, single IV doses) plus animal pharmacology in rats, monkeys, lambs, calves and chicks; no controlled trials of repeated use found.
Published human studies and reports (these describe trial populations, not SoluneFit claims):
- Healthy men, single IV bolus (Bowers 1990): 0.1, 0.3 and 1.0 µg/kg IV in 18 men; mean peak GH 7.6, 16.5 and 68.7 µg/L vs 1.2 µg/L with placebo; submaximal doses plus GHRH 1 µg/kg acted synergistically.
- Animal pharmacology (Bowers 1984): Active on rat pituitary cells in vitro at 1-10 ng/mL; after IV injection in rats GH rose within 2 min and peaked at 10-20 min.
Mechanism, as reported
Activates the ghrelin (GH secretagogue) receptor, releasing GH independently of and synergistically with GHRH. At higher doses it also raises prolactin and cortisol.
Practical record
- Studied routes: intravenous, subcutaneous.
- Typical supply: Sold as lyophilised powder vials on the research-chemical market (no approved product).
Safety signals on record
- Reported adverse events: In the 18-man study, no adverse clinical effects or laboratory abnormalities were seen; prolactin and cortisol roughly doubled at 1 µg/kg. FDA notes possible cortisol effects and raised blood glucose from reduced insulin sensitivity.
- Contraindications: None established (no label).
- Interactions: None documented.
- Notes: WADA Prohibited List 2026 (in force 1 Jan 2026), S2.2.4 names GHRP-6 among GH-releasing peptides, prohibited at all times (in and out of competition), non-specified. Human half-life: not established (no primary PK source found). As a ghrelin mimetic it is expected to increase appetite (UNVERIFIED in a primary GHRP-6 human source).
Sources
- Bowers CY et al. On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology 1984;114(5):1537-45 (1984)
- Bowers CY et al. Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone. J Clin Endocrinol Metab 1990;70(4):975-82 (1990)
- FDA. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (categories 1-3, updated 14 May 2026) (2026)
- FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (category 2 under the 503A/503B interim policies; content current as of 22 Apr 2026) (2026)
- FDA Warning Letter to ImprimisRx CA Inc (GHRP-2 and GHRP-6 not on the 503A bulks list), 26 Mar 2019 (2019)
- World Anti-Doping Agency. The 2026 Prohibited List (International Standard), in force 1 January 2026 — section S2.2.4 Growth hormone releasing factors (S2.2.4 text checked against a mirrored copy of this PDF; wada-ama.org blocked automated download) (2025)
General wellness education, not medical advice. Unapproved compounds have no established dosing, purity standard, or safety profile.