Pinc PeptideThe girly peptide research blog

GHRP-6 · Dose evidence · updated 8 October 2026

GHRP-6 dosage: what studies actually used

The short answer

We found no established GHRP-6 dose for any use: as of 7 October 2026 it is not approved in the US, and we found no trial of it for muscle gain or fat loss23. Most human studies gave single doses, often set per kilogram of body weight, such as 1 µg/kg into a vein in growth hormone (GH) tests or 300 µg/kg by mouth, and measured hormones, sleep or drug levels4567. The only treatment trials we found, in stroke, gave 3.5 or 5 mg into a vein twice a day for 7 days, always together with EGF, a growth factor89. This page reports those doses and is not dosing advice.

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

StudyWhoPeopleDose and routeWhat happened
Popovic 2000, multicenter diagnostic study Adults with pituitary disease and severe GH deficiency (125) and healthy people (125) 250 GHRP-6 1 µg/kg plus GHRH (growth hormone-releasing hormone) 1 µg/kg, once
Into a vein · One test; blood sampled for 120 minutes		 Average GH peaks were 59.2 µg/L in healthy people and 4.1 µg/L in patients, and a peak of 15.0 µg/L separated the two groups4. The test caused no side effects, and age, sex and body fat did not affect it4.
COURAGE-2 (Hernández-Bernal 2026), randomized open-label phase III trial Patients within 12 hours of the start of an ischemic stroke, one caused by a blocked blood vessel 188 5 mg with EGF 75 µg, twice a day; or standard care alone
Into a vein · 7 days		 The trial missed its main goal: disability, daily function and survival did not differ from standard care9. Severe adverse events occurred in 48 of the 188 patients, 30 of them among the 95 treated, and none was judged treatment-related; in a subgroup of 27 with severe stroke, treated patients had less disability at 6 months9.
Hernández-Bernal 2024, randomized open-label phase I/II trial Adults aged 18 to 80 within 12 hours of an ischemic stroke 36 3.5 or 5 mg, each with EGF 75 µg, twice a day; or standard care
Into a vein · 7 days		 Serious adverse events occurred in 9 of 16 on standard care, 3 of 10 on 3.5 mg and 2 of 10 on 5 mg, and only two events, in one patient on 3.5 mg, were attributed to the treatment8. The authors reported better recovery with treatment at 90 and 180 days8.
Bowers 1992 Healthy men (5), and short children with varying GH deficiency (9) who had stopped GH treatment for 2 to 3 weeks 14 Men: 100 or 300 µg/kg by mouth, compared with results after 0.1, 0.3 and 1.0 µg/kg into a vein; children: 300 µg/kg by mouth
By mouth; comparison doses into a vein · Single doses		 In the men, peak GH rose 63-fold after 100 µg/kg and 202-fold after 300 µg/kg5. Four of the 9 children responded like the men, 3 had low responses and 2 had none that could be measured5. Because 300 µg/kg by mouth released about as much GH as 1 µg/kg into a vein, the authors calculated that GHRP-6 by mouth has about 0.3% of the activity it has into a vein5.
Sigalos 2017, chart review Men on testosterone, average age 33.2, seeking more lean mass and less fat; 14 of 105 met the inclusion criteria 14 100 µg each of GHRP-6, GHRP-2 and sermorelin, three times a day
Injection under the skin · Average 134 days		 IGF-1, a blood marker of GH action, rose from 159.5 to 239.0 ng/mL10. The full text gives the route and says body measurements were not available for most of the men at follow-up, which the authors say limited what the study could show about body mass index and lean mass1.
Bellone 1995 Short children aged 6.2 to 10.5 (9 boys, 4 girls), before puberty, with normal growth rate and bone age 13 300 µg/kg once, compared with GHRH 1 µg/kg into a vein
By mouth · Single tests		 In the first 7 children, GH rose from 1.1 to a peak of 18.8 µg/L at 60 minutes, similar to the response to GHRH11.
Muller 2001, double-blind, placebo-controlled study Healthy, non-obese men given pegvisomant (a drug that blocks GH’s receptor) or placebo 10 1 µg/kg once per test
Not stated in the abstract · Single tests, fed and after 3 days of fasting		 With GH’s receptor blocked and the men fed, GHRP-6 raised insulin from 10.3 to 81.3 mU/L and glucose from 4.2 to 6.0 mmol/L; these changes were not seen during fasting or without the blocker12.
Cabrales 2013, drug-level study Healthy men 9 100, 200 or 400 µg/kg once
Into a vein · Single dose		 Total exposure tended to rise in proportion to the dose, and 4 of the 9 men had unusual spikes in GHRP-6 levels while it was being cleared7.
Ghigo 1994 Healthy older women aged 65 to 82 7 Test dose of 300 µg/kg before and after 4 days of twice-daily treatment (treatment dose not stated in the abstract); GHRH 1 µg/kg into a vein for comparison
By mouth · 4 days		 Before treatment, 300 µg/kg by mouth raised GH to a peak of 10.7 µg/L, higher than the 5.1 µg/L after GHRH, and after 4 days the response held, with a peak of 16.8 µg/L13. IGF-1 did not rise significantly, at 77.1 µg/L before and 84.1 µg/L after13.
Frieboes 1995, placebo-controlled sleep study Healthy men (number not given in the abstract) – 50 µg four times; or placebo
Into a vein · One night		 Compared with placebo, GH (15.4 vs 5.5 ng/mL), ACTH, the pituitary hormone that drives cortisol (21.0 vs 16.6 pg/mL), and cortisol (56.0 vs 25.2 ng/mL) were higher in the first part of the night6. Light (stage 2) sleep increased, while deep (slow-wave) sleep did not change6.
Frieboes 1999, placebo-controlled sleep study Healthy young men (number not given in the abstract) – 300 µg/kg in coated capsules, or 30 µg/kg into the nose or under the tongue, once; or placebo
By mouth, into the nose or under the tongue · One night		 The dose into the nose raised GH through the night, the dose under the tongue showed only a trend toward more GH, and the dose by mouth left GH, ACTH and cortisol unchanged and reduced stage 2 sleep late in the night14.

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Studies in adults gave one IV dose of 1 µg/kg combined with GHRH 1 µg/kg for diagnosis4; four IV doses of 50 µg in a sleep study6; 1 µg/kg with or without pegvisomant12; and one IV dose of 100 to 400 µg/kg to measure drug levels7. By mouth, studies used single doses of 100 or 300 µg/kg in men and 300 µg/kg in children511, and a 300 µg/kg test dose in older women before and after 4 days of twice-daily treatment, at a dose the abstract does not state13. A sleep study compared 300 µg/kg by mouth with 30 µg/kg into the nose or under the tongue14. The stroke trials gave 3.5 or 5 mg IV with EGF twice daily for 7 days89. These studies measured hormones, sleep, drug levels or stroke recovery, not muscle or fat3.

In animal studies

Pigs: one 400 µg/kg dose in a heart-attack model cut infarct mass by 78% and thickness by 50% vs saline15. Dogs: daily IV doses of CIGB-500 (GHRP-6) at 300 to 2000 µg/kg for 28 days caused only temporary, reversible signs such as drooling, inactivity and a slower heart rate, and the highest dose was the no-observed-adverse-effect level16. Rats: injections under the skin once or twice daily for 9 or 25 days increased weight gain in young rats17.

What users report Anecdotal · not validated · not a recommendation

A 2026 medical review compiled bodybuilding-forum reports: 100 to 300 µg under the skin or into muscle, 2 or 3 times a day3.

Half-life and how it is taken

Half-life
About 2.5 hours after a dose into a vein in healthy men (an older method gave 20 minutes)7In 9 healthy men given one IV dose of 100, 200 or 400 µg/kg and measured by mass spectrometry, the distribution half-life was 7.6 minutes and the elimination half-life 2.5 hours, and levels fell to the lowest measurable amount (5 ng/mL) by 12 hours7. A 1992 study that measured GHRP-6 with an antibody-based assay reported a serum half-life of 20 minutes after oral and IV doses; after a dose by mouth, GH returned to baseline within 150 to 180 minutes5.
Routes
  • Intravenous injection (hormone tests, sleep studies and the stroke trials)
  • Injection under the skin or into muscle (the usual gray-market routes)
  • By mouth (tested in adults and children)
  • Into the nose or under the tongue (tested in healthy men)

Test doses versus treatment doses

Most human studies gave one dose and measured hormones over the next few hours451112. Even the largest, a diagnostic study in 250 people, gave a single test dose of 1 µg/kg into a vein together with GHRH; a one-time test dose is not a treatment dose4.

The only treatment doses we found come from the two stroke trials, which always gave GHRP-6 together with EGF89. Both were open-label, meaning everyone knew who was treated, so they cannot show what GHRP-6 itself did, and the larger trial missed its main goal89. We found no trial of those doses for any other use, and we did not verify whether any GHRP-6 product is approved in Cuba, where the first trial was registered8.

What the studies measured, and what it is promoted for

A 2026 medical review describes peptides that act on the GH system, GHRP-6 among them, as used off-label for physique and performance, and promoted for recovery, fat loss and muscle building3. It notes that off-label claims of better ‘recomposition’ (more muscle, less fat) extrapolate from GHRP-6’s hormone effects, while direct evidence for body-composition changes in people remains limited3. Claim by claim:

  • Muscle and fat: we found no trial. The only study we found of people using it for that goal, a chart review of 14 men taking it with GHRP-2 and sermorelin, measured IGF-1, and body measurements were missing for most of the men110.
  • Heart protection: the review says this evidence comes from animal and lab studies and lacks confirmation from human clinical trials3.
  • Healing and recovery: the only treatment trials we found were the two stroke trials, which always paired it with EGF, and the larger one missed its main goal89.
  • Sleep: 50 µg four times into a vein increased light (stage 2) sleep but not deep sleep, and a dose by mouth reduced stage 2 sleep late in the night614.
  • Appetite: the review describes a consistent appetite-stimulating response3, but we found no human study that measured appetite or food intake after GHRP-6.

Why a gray-market dose is uncertain

As of 7 October 2026, Finnrick, a service that publishes lab results for peptide samples, listed no GHRP-6 tests, so no independent data show how much GHRP-6 gray-market vials hold18. FDA recall records name GHRP-6 in 19 compounded sermorelin products, recalled by 8 US pharmacies between 21 May 2012 and 23 May 2019, all for sterility problems19. A vial may also hold a look-alike: doping-control chemists found glycine-extended GHRP-6, which carries an extra amino acid, in powders seized by Danish customs20.

Questions people ask

How much GHRP-6 should I take?

We found no established dose for any use: it is not approved in the US, and we found no trial of it for muscle gain or fat loss23. Studies used single test doses such as 1 µg/kg into a vein or 300 µg/kg by mouth, and stroke trials gave 3.5 or 5 mg into a vein twice a day with EGF458. By our reading, US pharmacies may not compound GHRP-623242526.

What dose of GHRP-6 was used in stroke trials?

3.5 or 5 mg into a vein twice a day for 7 days, always with 75 µg of EGF, started within 12 hours of the stroke89. The larger trial, in 188 patients, missed its main goal9.

Does GHRP-6 work by mouth?

It raised GH at 100 and 300 µg/kg by mouth, and the 1992 study calculated that by mouth it has about 0.3% of the activity it has into a vein5. In one sleep study, 300 µg/kg in coated capsules left GH, ACTH and cortisol unchanged14.

Does GHRP-6 improve sleep?

In one study, 50 µg four times into a vein increased light (stage 2) sleep but did not change deep sleep6. In another, a dose into the nose raised GH through the night, and a dose by mouth reduced stage 2 sleep late in the night14.

Has GHRP-6 been tested for muscle growth?

We found no trial of it for muscle gain or fat loss, and a 2026 review calls direct evidence for body-composition changes in people limited3. A chart review of 14 men who used it with GHRP-2 and sermorelin measured IGF-1, and body measurements were missing for most of them110.

Go deeper

Sources

  1. 1Growth Hormone Secretagogue Treatment in Hypogonadal Men Raises Serum Insulin-Like Growth Factor-1 Levels (full text) American Journal of Men’s Health, Nov 2017. pmc.ncbi.nlm.nih.gov
  2. 2Drugs@FDA search for active ingredients named GHRP (openFDA drugsfda endpoint; no matches) U.S. Food and Drug Administration (openFDA), accessed 7 Oct 2026. api.fda.gov · data query
  3. 3The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration Frontiers in Endocrinology, 18 Jun 2026. frontiersin.org
  4. 4GH-releasing hormone and GH-releasing peptide-6 for diagnostic testing in GH-deficient adults The Lancet, 30 Sep 2000. pubmed.ncbi.nlm.nih.gov
  5. 5The growth hormone-releasing activity of a synthetic hexapeptide in normal men and short statured children after oral administration The Journal of Clinical Endocrinology & Metabolism, Feb 1992. pubmed.ncbi.nlm.nih.gov
  6. 6Growth hormone-releasing peptide-6 stimulates sleep, growth hormone, ACTH and cortisol release in normal man Neuroendocrinology, May 1995. pubmed.ncbi.nlm.nih.gov
  7. 7Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers European Journal of Pharmaceutical Sciences, 23 Jan 2013. pubmed.ncbi.nlm.nih.gov
  8. 8Combination therapy of Epidermal Growth Factor and Growth Hormone-Releasing Hexapeptide in acute ischemic stroke: a phase I/II non-blinded, randomized clinical trial Frontiers in Neurology, 2024. pubmed.ncbi.nlm.nih.gov
  9. 9Phase III Open-Label, Randomized Clinical Trial of Epidermal Growth Factor and Growth Hormone Releasing Hexapeptide in Acute Ischemic Stroke Journal of Clinical Neuroscience, Oct 2026. pubmed.ncbi.nlm.nih.gov
  10. 10Growth Hormone Secretagogue Treatment in Hypogonadal Men Raises Serum Insulin-Like Growth Factor-1 Levels American Journal of Men’s Health, Nov 2017. pubmed.ncbi.nlm.nih.gov
  11. 11Growth hormone-releasing effect of oral growth hormone-releasing peptide 6 (GHRP-6) administration in children with short stature European Journal of Endocrinology, Oct 1995. pubmed.ncbi.nlm.nih.gov
  12. 12Blockade of the growth hormone (GH) receptor unmasks rapid GH-releasing peptide-6-mediated tissue-specific insulin resistance The Journal of Clinical Endocrinology & Metabolism, Feb 2001. pubmed.ncbi.nlm.nih.gov
  13. 13Growth hormone-releasing activity of growth hormone-releasing peptide-6 is maintained after short-term oral pretreatment with the hexapeptide in normal aging European Journal of Endocrinology, Nov 1994. pubmed.ncbi.nlm.nih.gov
  14. 14Effects of growth hormone-releasing peptide-6 on the nocturnal secretion of GH, ACTH and cortisol and on the sleep EEG in man: role of routes of administration Journal of Neuroendocrinology, Jun 1999. pubmed.ncbi.nlm.nih.gov
  15. 15Growth-hormone-releasing peptide 6 (GHRP6) prevents oxidant cytotoxicity and reduces myocardial necrosis in a model of acute myocardial infarction Clinical Science, Feb 2007. pubmed.ncbi.nlm.nih.gov
  16. 16Subchronic safety assessment of CIGB-500 in beagle dog after repeated daily dose administration over 28 days Regulatory Toxicology and Pharmacology, May 2025. pubmed.ncbi.nlm.nih.gov
  17. 17On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone Endocrinology, May 1984. pubmed.ncbi.nlm.nih.gov
  18. 18GHRP-6: safety testing results and vendor ratings (no published tests) Finnrick, accessed 7 Oct 2026. finnrick.com
  19. 19FDA drug recall (enforcement report) records naming GHRP, via the openFDA drug/enforcement API U.S. Food and Drug Administration (openFDA), 30 Sep 2026. api.fda.gov · data query
  20. 20Glycine-modified growth hormone secretagogues identified in seized doping material Drug Testing and Analysis, Feb 2019. pubmed.ncbi.nlm.nih.gov
  21. 21Effects 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, 1997. pubmed.ncbi.nlm.nih.gov
  22. 22GHRP KAKEN100 Injection (注射用GHRP科研100): package insert, revised July 2025 (in Japanese) KEGG MEDICUS (JAPIC package insert data), Jul 2025. kegg.jp
  23. 23Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  24. 24Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  25. 25Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act U.S. Food and Drug Administration, 14 May 2026. fda.gov
  26. 26Bulk Drug Substances Nominated for Use in Compounding Under Section 503B of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 21 Mar 2025. fda.gov

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.