GHRP-6 is a synthetic six-amino-acid peptide that acts on the ghrelin receptor and triggers growth hormone release. It was the first of the GHRPs studied widely in people. It is not FDA approved, and the FDA lists it among bulk substances that may present significant safety risks in compounding.
Also known as: Growth hormone releasing hexapeptide.
Powder vials are usually labeled 5 mg or 10 mg.
Water and syringe-unit charts by vial size: 5 mg · 10 mg
Here is the math for a 5 mg vial mixed with 2 mL of bacteriostatic water, drawing 100 mcg with a U-100 insulin syringe (1 mL = 100 units).
5 mg ÷ 2 mL = 2.5 mg/mL100 mcg ÷ 2.5 mg/mL = 0.04 mL0.04 mL × 100 = 4 units| Amount | Volume | U-100 syringe |
|---|---|---|
| 50 mcg | 0.02 mL | 2 units |
| 100 mcg | 0.04 mL | 4 units |
| 200 mcg | 0.08 mL | 8 units |
Adding more water doesn't change how much GHRP-6 is in the vial. It only spreads it over more liquid, so each draw is bigger and easier to read.
| Water added | Concentration | Volume | U-100 syringe |
|---|---|---|---|
| 3 mL | 1.67 mg/mL | 0.06 mL | 6 units |
| 5 mL | 1 mg/mL | 0.1 mL | 10 units |
For any other vial size or amount, the free peptide reconstitution calculator works backwards from the amount you want and suggests a water volume that lands on a clean syringe mark.
Many human studies used GHRP-6 as a one-off test of how much growth hormone the pituitary can release, given into a vein. In children and adults with growth hormone deficiency the response was lower than in healthy people, with a lot of overlap between groups.
The FDA placed GHRP-6 in category 2 for 503B outsourcing facilities in September 2023. It cites a risk of immune reactions for some routes, limited safety data, and concerns about effects on cortisol and rising blood sugar from lower insulin sensitivity.
One study gave GHRP-6 into a vein to nine healthy men and measured an elimination half-life of about 2.5 hours (Cabrales 2013). There is no published figure for an injection under the skin, so we do not list one here.