Hexarelin was tested in people for a decade. In the longest adult trial pepmg found, its growth hormone response shrank by about 45% in 16 weeks.

The molecule

A six-amino-acid growth hormone releaser

Hexarelin, also called examorelin, is the hexapeptide His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2, a synthetic growth hormone-releasing peptide in the same family as GHRP-6 and GHRP-2 .[1][26] Its 1994 dose-finding study was led by a researcher from the medical department of Mediolanum Farmaceutici, a drug maker in Milan.[1]

In that double-blind, placebo-controlled study, 12 healthy men got single intravenous doses of 0.5, 1 and 2 µg/kg. Growth hormone peaked about 30 minutes after injection and returned to baseline within 240 minutes; mean peaks were 26.9, 52.3 and 55.0 ng/mL against 3.9 on placebo, so 2 µg/kg was close to the maximum response.[1] A Turin study in 12 healthy young volunteers found that 1 µg/kg intravenously released about twice as much growth hormone as the same dose of GHRH, and estimated the biological bioavailability at 77% under the skin, 4.8% by nose and 0.3% by mouth.[2]

The other hormones

Not only growth hormone

A London dose-response study in healthy men found intravenous hexarelin raised prolactin by up to about 180% from baseline and produced a step increase in cortisol of about 40% at 0.5 µg/kg.[3] In a placebo-controlled sleep study, 7 young volunteers given four 50 µg doses of hexarelin hourly from 10 p.m. to 1 a.m. had less deep (stage 4) sleep in the first half of the night, higher growth hormone and prolactin all night, and higher ACTH and cortisol in the first half.[11]

Repeated use

The response shrank over months and came back after stopping

A Manchester group gave 12 healthy elderly people 1.5 µg/kg under the skin twice daily for 16 weeks.[4][5] The growth hormone area under the curve after a test injection fell from 19.1 µg/L·h at the start to 13.1 at week 1, 12.3 at week 4 and 10.5 at week 16, then rose to 19.4 four weeks after treatment stopped. The authors called this a partial and reversible attenuation.[4] Serum IGF-1 and IGFBP-3 did not change significantly over the 20 weeks, and total body fat, lean body mass and bone mineral density had not changed significantly at week 16; of the bone markers, only one collagen-formation marker rose. The authors wrote that the biological impact of this schedule on the GH-IGF-1 axis "seems to be minimal."[4]

A companion report from the same group, using the same 16-week regimen, found the cortisol response to a test injection lower after 16 weeks than at baseline, recovering four weeks after stopping, with no change in the prolactin response or 24-hour urinary cortisol.[6] A one-day Turin study in 6 young men pointed the same way: after two or three injections, a further intravenous dose produced a blunted growth hormone response and no ACTH or cortisol response.[10]

Shorter courses gave a different answer. In a Turin paper reporting two small studies, 7 elderly people using nasal hexarelin three times daily for 8 days, and 7 elderly women taking 20 mg by mouth three times daily for 15 days, kept their growth hormone response, and the authors reported no side effects.[7] Both compared each person before and after treatment, and neither lasted longer than about two weeks.

Children

Faster growth in two small studies without a control group

A Tel Aviv group gave nasal hexarelin, 60 µg/kg three times daily, to 8 short prepubertal children for up to 8 months. IGF-1 rose from 10.4 to 14.1 nmol/L and growth velocity from 5.3 to 8.3 cm a year.[8] In a report on 7 children from the same group, treated for 6 to 10 months, the peak response to an intravenous test dose fell from 84.8 to 19.8 mU/L by the end of treatment, yet growth velocity still rose from 5.3 to 7.4 cm a year.[9] Neither study had an untreated comparison group, so the growth change cannot be separated from natural variation.

In 2003 Zvi Laron, who led the 1995 study, published a commentary titled "Intranasally and orally active GH secretagogues are useful clinical tools: so why are they not on the market?"[15]

The heart

Short-lived pumping gains after single intravenous doses

Turin researchers reported that one intravenous dose raised left ventricular ejection fraction in 9 healthy men (63% to a peak of 70%) and in 7 men with growth hormone deficiency (50% to 57%), even though the deficient men released almost no growth hormone.[12] In patients with severe left ventricular dysfunction, it raised ejection fraction in 5 with ischemic cardiomyopathy (22.6% to 26.2%) but not in 8 with dilated cardiomyopathy.[13] In 24 men under anesthesia for bypass surgery, split among hexarelin, GHRH, growth hormone and placebo, only hexarelin raised ejection fraction and cardiac output, for up to 90 minutes.[14]

All of these were single doses measured over minutes to hours. pepmg's PubMed searches found no published trial of repeated hexarelin dosing for a heart condition.[17][18]

Status

No approval, no 503A category, banned in sport

pepmg found no hexarelin or examorelin product in Drugs@FDA, searched through openFDA on October 27, 2026, and ClinicalTrials.gov returned no study for either name that day.[19][18] Under section 503A, a pharmacy may compound from a bulk substance with a USP or NF monograph, one that is a component of an FDA-approved drug, or one on FDA's 503A bulks list.[23] That list has six entries, none of them hexarelin.[24] Hexarelin also appears in none of FDA's three 503A nomination categories in the list updated May 14, 2026, while its relatives GHRP-2 and GHRP-6 sit in category 3, "nominated without adequate support."[22] It is not on FDA's compounding safety-risk page.[25] pepmg did not check USP monograph status.

FDA's NDC directory, read through openFDA on October 27, 2026, holds one bulk-ingredient listing for hexarelin acetate, from Darmerica, with a marketing start date of January 13, 2026.[20] FDA says an NDC "does not in any way denote FDA approval of the product."[21]

The World Anti-Doping Agency's 2026 Prohibited List names "examorelin (hexarelin)" among growth hormone-releasing peptides in class S2, prohibited at all times.[26] A 2015 Moscow anti-doping study gave nasal hexarelin to one volunteer to find the urinary metabolites that testing labs look for.[16]

The market

Mostly 5 mg listings

In pepmg's index generated October 26, 2026, 24 of the 102 vendors with listings carried hexarelin, 35 listings in all; 22 were 5 mg, and 4 were blends.[27] pepmg makes no claim about what is in any vendor's product. The trial doses above were given in micrograms per kilogram of body weight and are reported as published, not as guidance.

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