Split doses
Community- Dose
- 100–150 mcg
- How often
- 2–3 times daily, fasted
- How long
- 8–12 weeks, then 4–8 off
Often in the same shot as a GHRH analog such as CJC-1295. Not tested as repeated injections in any trial.
Draw 5–7.5 units5 mg + 2.5 mL
Human studiesGhrelin-receptor agonist (GHRP)
GHRP-6
Growth hormone releasing hexapeptide, SK&F 110679
- Common dose
- 100–150 mcg, 2–3× daily
- Cycle
- 12 weeks on, 4 off
- Vial sizes
- 5, 10 mg
- Typical draw
- 5 units5 mg with 2.5 mL, 100 mcg
A six-amino-acid synthetic peptide that activates the ghrelin (hunger hormone) receptor, triggering a short, strong pulse of growth hormone. It was one of the first GH-releasing peptides tested in people.
Evidence. Human data come from small physiology studies (1989–1995) that gave single IV doses or 24-hour infusions to healthy people and patients, and from later diagnostic tests pairing it with GHRH: GH rose sharply, and the response faded during constant infusion. No trials of repeated injections were found, and it has never been approved.
Status
- Approval
- Not approved as a drug in the US, the EU or elsewhere.
- US compounding
- Still in FDA Category 2 for outsourcing facilities (503B) as of April 2026, over immunogenicity risk and possible effects on cortisol and blood sugar. For pharmacy compounding (503A) it is in Category 3, nominated without adequate support (May 2026 list). Not on the July 2026 advisory committee agenda.
- Sport (WADA 2026)
- Banned in sportS2.2.4 growth hormone releasing factors: GH-releasing peptides (GHRPs), with GHRP-6 named. Banned at all times.
Category 2 is FDA’s list of bulk substances that may present significant safety risks in compounding. The 503A bulks list adds substances that pharmacies may compound with. Advisory committee votes are advice; FDA makes the final decision. Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026. Status of every compound.
How it works
GHRP-6 binds the ghrelin receptor (GHS-R1a), the receptor for the hunger hormone ghrelin, mostly in the hypothalamus, the brain area that controls the pituitary, and on the pituitary itself. In healthy men, a single IV dose set off a large, short GH pulse that was far larger when given with GHRH. In people whose hypothalamus is cut off from the pituitary it barely worked, showing it acts mainly through the brain. At the highest dose tested it also roughly doubled the hormones prolactin and cortisol.
TrialMainly from studies in people.
Not known
Whether repeated injections keep working is unclear: a 24-hour infusion blunted the response to a later dose by about two-thirds, and no trial of repeated injections exists.
Protocol
Trial
Bowers 1990
IV bolus of 0.1–1 mcg/kg in healthy men; GH rose with the dose, peaking at about 69 mcg/L after 1 mcg/kg.
Community
100–150 mcg per injection (about 1 mcg/kg), 2–3× daily on an empty stomach; some guides go up to 200–300 mcg.
- Frequency
- 2–3× daily
- Route
- Subcutaneous injection (community); IV and by mouth in trials
- Timing
- Fasted: 2+ hours after food and about 30 minutes before eating.
- Cycle
- 8–12 weeks on, then 4–8 weeks off.
12 weeks on, 4 off, shown over 26 weeks
Common protocols
The ways GHRP-6 is most often run, each tagged with where it comes from.
Before meals (appetite)
Community- Dose
- 100 mcg
- How often
- About 30 minutes before meals
- How long
- 4–8 weeks
Used for its hunger effect. No human trial has tested GHRP-6 for appetite.
Draw 5 units5 mg + 2.5 mL
Research IV bolus
Trial- Dose
- 1 mcg/kg (0.1–1 tested)
- How often
- Single dose
- How long
- One-off test
GH peaked at about 45 minutes (Ilson 1989); prolactin and cortisol about doubled at 1 mcg/kg (Bowers 1990).
Research 24-hour infusion
Trial- Dose
- 1 mcg/kg per hour
- How often
- Continuous
- How long
- 24 hours
GH secretion rose about 8-fold, but the response to a later GHRP-6 dose was blunted (Huhn 1993). Hospital research only.
Dosing by body weight
Trial0.1–1 mcg/kg. Bowers 1990 IV bolus in healthy men; Ilson 1989 gave 0.05–2.5 mcg/kg IV over 30 minutes. A 24-hour infusion ran at 1 mcg/kg per hour (Huhn 1993). Not subcutaneous doses.
At 70 kg, per dose7 mcg–70 mcg0.4–3.5 units at 5 mg + 2.5 mL
Taking it
Where it goes
Community use is subcutaneous injection (under the skin), rotating sites, on an empty stomach. Human studies gave it into a vein (IV), as a single dose or a 24-hour infusion, and by mouth, where it was only about 0.3% as potent as IV.
If you miss a dose
No published guidance. Skip the missed dose and take the next one on schedule; don’t double up.
What to expect
- About 45 min after an IV dose
GH peaks (68.7 mcg/L after 1 mcg/kg vs 1.2 on placebo) and is back to baseline by about 3.5 hours.
Trial - 15–20 min after an injection
Strong hunger, lasting 30–60 minutes, is the most reported effect.
Community - Over a 24-hour infusion
GH output rose about 8-fold and IGF-1 12–22%, but a GHRP-6 test dose afterward gave a peak of 7.9 vs 25 mcg/L after saline.
Trial - Weeks to months
Used for muscle gain, recovery and appetite; no human data on repeated injections support these uses.
Community
Side effects and what to do
Hunger, often intense, starting within about 20 minutes
The most reported effect. Lower the dose or stop if it’s unwanted.
Higher prolactin and cortisol (about 2× after 1 mcg/kg IV)
Seen in healthy men; FDA also cites cortisol effects. Matters more with pituitary or adrenal conditions.
Higher blood sugar from lower insulin sensitivity
Cited by FDA. Check fasting glucose, especially with prediabetes or diabetes.
Water retention, tingling or numbness
Reported by users as GH-related effects. Lower the dose or stop if it persists.
Site redness, pain or infection (unregulated vials)
Use sterile technique. Spreading redness, heat or pus needs medical care.
Stop and get medical help
Get medical help for hives, face or throat swelling or trouble breathing, signs of very high blood sugar (extreme thirst, frequent urination), or a hot, spreading red injection site with fever.
Who should avoid it
No product label covers GHRP-6, so these come from human studies and from precautions based on how it works. Most important first.
- Diabetes or high blood sugar
- PrecautionFDA cites higher blood sugar from lower insulin sensitivity (the body responding less to insulin) as a safety concern for GHRP-6. Growth hormone also raises blood sugar.
- Pituitary or adrenal disorders
- TrialProlactin and cortisol about doubled after an IV dose in healthy men, and FDA cites possible effects on cortisol. These changes matter more when those glands already work abnormally.
- Anyone with active or past cancer
- PrecautionIt raises growth hormone and IGF-1, which promote cell growth. No study has tested whether it affects cancer.
- Pregnancy or breastfeeding
- PrecautionNo human safety data exist.
- Anyone relying on product quality
- PrecautionIt isn’t an approved drug, so vials have no regulated standard for identity, purity or sterility; FDA cites a risk of immune reactions from clumped peptide and impurities.
Interactions
Only interactions stated on a product label or measured in a human study are listed.
- GHRH (growth-hormone-releasing hormone, given by IV)
- TrialGiven together in healthy adults, GH release was larger than the sum of each alone; after a 24-hour GHRP-6 infusion, the response to GHRH roughly doubled.
- Glucocorticoids (such as dexamethasone)
- TrialA single dose of dexamethasone taken 3.5 hours earlier increased the GH response to GHRP-6 in healthy adults (8 per group).
Trial: seen in human studies, or a group those studies left out. Precaution: follows from how it works or from a related drug, and hasn’t been tested. This isn’t a complete list: a pharmacist or doctor can check a specific medicine or condition.
Tracking and pairing
Worth tracking
- IGF-1
- Fasting glucose
- Body weight and appetite
Often paired with
- CJC-1295 (no DAC)
Common pairing: a GHRH analog plus a GHRP. GHRP-6 and natural GHRH released GH synergistically in healthy men (Bowers 1990), but this combination was never tested.
Human studies
5 key published human studies, with how many people took part. Animal studies aren’t listed here.
-
Peak GH was 7.6, 16.5 and 68.7 mcg/L vs 1.2 on placebo; the lower doses plus GHRH released GH synergistically, prolactin and cortisol about doubled only at 1 mcg/kg, and there were no adverse effects or lab abnormalities.
- Design
- Placebo-controlled dose-response study in healthy men (randomization not described)
- Dose
- 0.1, 0.3 and 1 mcg/kg IV bolus, alone and with GHRH
- Length
- Single doses
Bowers et al., J Clin Endocrinol Metab 1990, PMID 2108187
-
GH secretion rose about 8-fold and IGF-1 12–22%, but the GH peak to a later GHRP-6 dose fell to 7.9 vs 25 mcg/L after saline, while the response to GHRH rose (24 vs 11 mcg/L).
- Design
- Crossover study in healthy young men, 24-hour saline vs GHRP-6 infusion, then test doses (randomization not described)
- Dose
- 1 mcg/kg per hour infusion
- Length
- 24 hours
Huhn et al., J Clin Endocrinol Metab 1993, PMID 8496311
-
GH peaked at 45 minutes (63.0 mcg/L at 1 mcg/kg) and returned to baseline by 210 minutes; LH, FSH, TSH and ACTH didn’t change, and it was well tolerated.
- Design
- Dose-ranging study with saline controls in healthy men (randomization not described)
- Dose
- 0.05–2.5 mcg/kg IV over 30 minutes (17 men; 8 got saline)
- Length
- Single dose
Ilson et al., J Clin Endocrinol Metab 1989, PMID 2543692
-
In controls, GHRP-6 released about 3× more GH than GHRH (area under the curve 1,435 vs 484), and the two together more than their sum (3,772); in patients, GHRP-6 released almost none (97), showing it works mainly through the hypothalamus.
- Design
- Comparative physiology study: patients whose hypothalamus is cut off from the pituitary (hypothalamic–pituitary disconnection) vs matched healthy controls
- Dose
- 90 mcg IV, alone and with GHRH
- Length
- Single tests
Popovic et al., J Clin Endocrinol Metab 1995, PMID 7883854
-
In men, peak GH rose 63- and 202-fold over baseline, but by mouth it had only about 0.3% of IV potency; serum GHRP-6 fell with a half-life of about 20 minutes. Four of 9 children responded like adults and 2 not at all.
- Design
- Single-dose study of oral dosing in healthy men and in children with GH deficiency (no placebo described)
- Dose
- 100 and 300 mcg/kg by mouth in 5 men; 300 mcg/kg in 9 children
- Length
- Single doses
Bowers et al., J Clin Endocrinol Metab 1992, PMID 1730807
Limits of the evidence
GHRP-6’s human record is small studies from 1989–1999, each with 8–25 people, mostly healthy men, given single IV or oral doses or a 24-hour infusion. No trial has tested repeated injections, so use for weeks, long-term safety and product purity are untested. A 24-hour infusion blunted the response to a later dose, so constant use may weaken the effect.
Mixing your vial
| Vial | Water | Common dose | Draw | Strength | Action |
|---|---|---|---|---|---|
| 5 mg | 2.5 mL | 100 mcg | 5 units (0.05 mL) | 2 mg/mL | |
| 10 mg | 5 mL | 100 mcg | 5 units (0.05 mL) | 2 mg/mL |
With 2.5 mL in a 5 mg vial (or 5 mL in a 10 mg vial, if it holds that much), each 100 mcg is 5 units on a U-100 syringe.
Dose chart
Syringe units for common doses at different water volumes. Select a cell to open it in the calculator.
| Dose | Water added | |||
|---|---|---|---|---|
| 1 mL | 2 mL | 2.5 mL | 3 mL | |
| 100 mcg | ||||
| 150 mcg | ||||
| 200 mcg | ||||
| 250 mcg | ||||
| 300 mcg | ||||
U-100 insulin syringe: 100 units is 1 mL. Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.
Datasheet
- Half-life
- about 2.5 hours TrialElimination half-life after a single IV dose in 9 healthy men, following a fast first phase of about 8 minutes. An older study using a less specific blood test measured about 20 minutes after IV and oral doses.
- Type
- Peptide, 6 amino acids
- Molecular weight
- 873 g/mol
- Formula
- C46H56N12O6
- Sequence
- H-(D-Trp)-A-W-(D-Phe)-K-NH2
- Storage before use
- Freezer (−20 °C) for long-term storage; fridge for short periods.
- After mixing or opening
- Fridge (2–8 °C); use within about 4 weeks.
- Half-life: Cabrales et al., Eur J Pharm Sci 2013 (doi:10.1016/j.ejps.2012.10.006), as cited in Dominikowski et al., Front Endocrinol 2026; Bowers et al., J Clin Endocrinol Metab 1992, PMID 1730807
- Molecule: PubChem CID 9919153 (growth hormone releasing hexapeptide, SK&F 110679; free base)
- Storage: Community Common practice; no approved label exists for this peptide
Every compound side by side: the half-life chart and the storage chart.
Cautions
- Strong hunger within about 20 minutes of a dose is the most reported effect.
- FDA cites possible effects on cortisol and higher blood sugar from lower insulin sensitivity, plus immunogenicity risk.
- Prolactin and cortisol about doubled after a 1 mcg/kg IV dose in healthy men.
- Constant exposure blunts the response: after a 24-hour infusion, a test dose released about two-thirds less GH.
- No trials of repeated injections; long-term safety is unknown.
Questions
What is GHRP-6?
A six-amino-acid synthetic peptide that activates the ghrelin (hunger hormone) receptor, triggering a short, strong pulse of growth hormone. It was one of the first GH-releasing peptides tested in people.
How does GHRP-6 work?
GHRP-6 binds the ghrelin receptor (GHS-R1a), the receptor for the hunger hormone ghrelin, mostly in the hypothalamus, the brain area that controls the pituitary, and on the pituitary itself. In healthy men, a single IV dose set off a large, short GH pulse that was far larger when given with GHRH. In people whose hypothalamus is cut off from the pituitary it barely worked, showing it acts mainly through the brain. At the highest dose tested it also roughly doubled the hormones prolactin and cortisol. Whether repeated injections keep working is unclear: a 24-hour infusion blunted the response to a later dose by about two-thirds, and no trial of repeated injections exists.
Is GHRP-6 FDA-approved?
Not approved as a drug in the US, the EU or elsewhere. Still in FDA Category 2 for outsourcing facilities (503B) as of April 2026, over immunogenicity risk and possible effects on cortisol and blood sugar. For pharmacy compounding (503A) it is in Category 3, nominated without adequate support (May 2026 list). Not on the July 2026 advisory committee agenda.
What is the usual GHRP-6 dose?
From human studies (Bowers 1990): IV bolus of 0.1–1 mcg/kg in healthy men; GH rose with the dose, peaking at about 69 mcg/L after 1 mcg/kg. From community reports, not established: 100–150 mcg per injection (about 1 mcg/kg), 2–3× daily on an empty stomach; some guides go up to 200–300 mcg. These are the amounts sources reference, not recommendations.
How much water do I mix GHRP-6 with?
There’s no single right amount, because the water only sets the strength. With 2.5 mL of bacteriostatic water in a 5 mg vial, the strength is 2 mg/mL, so 100 mcg is 5 units on a U-100 insulin syringe. More water makes small doses easier to measure. The dose chart above shows other volumes.
Who should avoid GHRP-6?
No product label covers GHRP-6, so these come from human studies and from precautions based on how it works. Diabetes or high blood sugar: FDA cites higher blood sugar from lower insulin sensitivity (the body responding less to insulin) as a safety concern for GHRP-6. Growth hormone also raises blood sugar. Pituitary or adrenal disorders: Prolactin and cortisol about doubled after an IV dose in healthy men, and FDA cites possible effects on cortisol. These changes matter more when those glands already work abnormally. Anyone with active or past cancer: It raises growth hormone and IGF-1, which promote cell growth. No study has tested whether it affects cancer. The “Who should avoid it” section lists 2 more groups and 2 interactions.
What is the half-life of GHRP-6?
About 2.5 hours, measured in human studies. Elimination half-life after a single IV dose in 9 healthy men, following a fast first phase of about 8 minutes. An older study using a less specific blood test measured about 20 minutes after IV and oral doses.
How should GHRP-6 be stored?
Before mixing: Freezer (−20 °C) for long-term storage; fridge for short periods. After mixing: Fridge (2–8 °C); use within about 4 weeks. This is common practice; no product label covers it.
Is GHRP-6 banned in sport?
Yes. S2.2.4 growth hormone releasing factors: GH-releasing peptides (GHRPs), with GHRP-6 named. Banned at all times.
Has GHRP-6 been studied in people?
Yes. The human studies section lists 5 published studies. The largest, from 1989, included 25 people. GH peaked at 45 minutes (63.0 mcg/L at 1 mcg/kg) and returned to baseline by 210 minutes; LH, FSH, TSH and ACTH didn’t change, and it was well tolerated.
Sources
- Bowers et al., GHRP-6 dose response and synergy with GHRH in normal men (J Clin Endocrinol Metab 1990) PMID 2108187
- Huhn et al., 24-hour GHRP-6 infusion blunts the response to a later dose (J Clin Endocrinol Metab 1993) PMID 8496311
- FDA: bulk drug substances for compounding that may present significant safety risks (GHRP-6), April 2026
For the protocol details
- Ilson et al., first human dose-ranging study of GHRP-6 (J Clin Endocrinol Metab 1989) PMID 2543692
- Bowers et al., GHRP-6 by mouth in men and children (J Clin Endocrinol Metab 1992) PMID 1730807
- Dominikowski et al., review of GH-axis peptides, including GHRP-6 pharmacokinetics (Front Endocrinol 2026) doi:10.3389/fendo.2026.1822475
For how it works, who should avoid it and the limits of the evidence
- Popovic et al., GHRP-6 works mainly through the hypothalamus (J Clin Endocrinol Metab 1995) PMID 7883854
- Pinto et al., dexamethasone increases the GH response to GHRP-6 (Clin Endocrinol 1999) PMID 10583306
- Howard et al., the GH secretagogue (ghrelin) receptor in pituitary and hypothalamus (Science 1996) PMID 8688086
Doses tagged Community come from public dosing guides and user reports, checked against at least two of them. Those sites aren’t named here because many of them sell peptides or earn commissions on them.