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Head-to-head

GHRP-2 vs Hexarelin

Close cousins at the ghrelin receptor: one is more potent, one has a defined diagnostic role, and both drag cortisol along and fade with repeated dosing.

By Julian RothResearch & dataUpdated October 2026

Short answer

GHRP-2 and hexarelin both have human clinical data, so the deciding factor is what you want them for. GHRP-2 suits someone focused on muscle, while hexarelin is aimed at muscle and recovery. For GHRP-2, five days of daily injections in healthy men did not raise IGF-1, and the GH response faded.

GHRP-2

Pralmorelin

Clinical data

Genuinely raises GH (and is an approved diagnostic in Japan), but the same dose lifts cortisol, prolactin and appetite, and desensitizes — no anti-aging outcomes.

Full GHRP-2 evidence review

Hexarelin

Clinical data

One of the most potent GH secretagogues studied — but it also raises cortisol and prolactin, desensitizes with repeated use, and is unapproved.

Full Hexarelin evidence review

GHRP-2 vs Hexarelin: head to head

FDA status / approved use

GHRP-2

Approved in Japan only as a growth-hormone diagnostic; not FDA-approved; sold as gray-market research peptide

Hexarelin

Not an approved drug; sold as unregulated research material; prohibited by WADA
Marketed for

GHRP-2

Muscle, 'anti-aging'

Hexarelin

Muscle, recovery, 'anti-aging'
Outcome areas

GHRP-2

Muscle / strength / lean mass; Longevity / lifespan

Hexarelin

Muscle / strength / lean mass; Injury recovery / tissue repair; Longevity / lifespan
Evidence grade

GHRP-2

Clinical data

Hexarelin

Clinical data
How it works

GHRP-2

Activates the ghrelin receptor to trigger a pulse of growth hormone from the pituitary

Hexarelin

Acts at the ghrelin receptor to trigger pituitary GH release; also binds CD36
Route and dosing

GHRP-2

Subcutaneous injection

Hexarelin

Subcutaneous injection
Headline human result

GHRP-2

Five days of daily injections in healthy men did not raise IGF-1, and the GH response faded

Hexarelin

Peak GH 68.4 µg/L vs 26.7 µg/L for GHRH after a 1 µg/kg IV dose in seven young men
Strongest evidence

GHRP-2

Bowers, Endocrine 2001GHRP-2 evidence reviewPubMed 11322505

Hexarelin

Maccario, Eur J Endocrinol 2002Hexarelin evidence reviewPubMed 11888836
Key safety signal

GHRP-2

Also raises cortisol, ACTH and prolactin and increases appetite

Hexarelin

Raises cortisol and prolactin; GH response fades with continued dosing
How it is obtained

GHRP-2

Sold gray-market as a research chemical; no approved or legitimately compounded human product

Hexarelin

Sold gray-market as a research chemical; no approved or legitimately compounded human product

marks a row where the two differ. “Not established” marks a cell the available evidence does not answer. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.

Clinical data:
Tested in humans — but investigational, discontinued, or proven only on a surrogate marker (not the marketed outcome).

Our verdict

This is a comparison between two versions of the same problem, not a search for a winner. Hexarelin is among the most potent GH secretagogues ever studied in humans and has a genuinely interesting, largely preclinical CD36 cardiovascular literature independent of GH, but it is non-selective, raising prolactin, ACTH and cortisol alongside GH, and its GH response shows tachyphylaxis, attenuating with continued administration. GHRP-2 has the more defined clinical footing: it is characterized well enough to serve as a GH-stimulation test and is an approved diagnostic agent in Japan, yet it carries the same cortisol, ACTH and prolactin spillover, reliably increases food intake, and in healthy young men a five-day course blunted the GH response without raising IGF-1. Neither is FDA-approved for body composition or anti-aging, both are sold as unverified research-only material, and both are prohibited in sport.

GHRP-2 fits if

GHRP-2 is the one to read if you want the clearest illustration of a peptide with real, narrow diagnostic validity being sold on the back of that legitimacy for uses it has never been shown to deliver.

Hexarelin fits if

Hexarelin is the one to read if you are drawn to raw potency, since it shows most plainly that potency without selectivity is a trade-off, and that the effect being bought is the one that erodes with use.

GHRP-2 vs Hexarelin: common questions

Is either GHRP-2 or hexarelin FDA-approved?
No. GHRP-2 is approved in Japan only as a growth-hormone diagnostic; not FDA-approved; sold as gray-market research peptide. Hexarelin is not an approved drug; sold as unregulated research material; prohibited by WADA.
Which has stronger human evidence, GHRP-2 or hexarelin?
Neither clearly. Both have human clinical data. The key source for GHRP-2 is Bowers, Endocrine 2001; for hexarelin, it is Maccario, Eur J Endocrinol 2002.
What are the main safety concerns with GHRP-2 and hexarelin?
GHRP-2 also raises cortisol, ACTH and prolactin and increases appetite. Hexarelin raises cortisol and prolactin; GH response fades with continued dosing.

Key studies behind each

GHRP-2

  1. Arvat E, di Vito L, Maccagno B, Broglio F, Boghen MF, Deghenghi R, Camanni F, Ghigo E. (1997). Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Comparison with the effects of GHRH, TRH and hCRH. Peptides. PubMed 9285939
  2. Bowers CY, Granda-Ayala R. (2001). Growth hormone/insulin-like growth factor-1 response to acute and chronic growth hormone-releasing peptide-2, growth hormone-releasing hormone 1-44NH2 and in combination in older men and women with decreased growth hormone secretion. Endocrine. PubMed 11322505
  3. Chihara K, Shimatsu A, Hizuka N, Tanaka T, Seino Y, Katofor Y; KP-102 Study Group. (2007). A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency. Eur J Endocrinol. PubMed 17609397
  4. Laferrère B, Abraham C, Russell CD, Bowers CY. (2005). Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men. J Clin Endocrinol Metab. PubMed 15699539

Hexarelin

  1. Arvat E, Maccario M, Di Vito L, Broglio F, et al. (2001). Endocrine activities of ghrelin, a natural growth hormone secretagogue (GHS), in humans: comparison and interactions with hexarelin, a nonnatural peptidyl GHS, and GH-releasing hormone. J Clin Endocrinol Metab. PubMed 11238504
  2. Maccario M, Veldhuis JD, Broglio F, Di Vito L, et al. (2002). Impact of two or three daily subcutaneous injections of hexarelin, a synthetic growth hormone (GH) secretagogue, on 24-h GH, prolactin, adrenocorticotropin and cortisol secretion in humans. Eur J Endocrinol. PubMed 11888836
  3. Raun K, Hansen BS, Johansen NL, Thøgersen H, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. PubMed 9849822
  4. Rahim A, O'Neill PA, Shalet SM. (1998). Growth hormone status during long-term hexarelin therapy. J Clin Endocrinol Metab. PubMed 9589671

The full evidence reviews

Where to get it

Where to get peptide therapy

Clinician-led telehealth services that prescribe compounded peptides. The specific peptides offered vary by provider — confirm GHRP-2 availability before ordering.

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