GHRP-6 common uses, half-life, side effects and more

GHRP-6 is the original synthetic growth hormone releasing peptide. It was made in the 1980s and became the template for the ones that followed. It turned out to act on the ghrelin receptor years before that receptor was identified. It makes the pituitary release its own growth hormone and it also drives hunger. It has never been approved anywhere and is sold as an unregulated research chemical. Almost everything published about it in people used a drip into a vein rather than an injection under the skin.

• Raising growth hormone without injecting growth hormone itself
• Appetite stimulation
• Recovery and body composition (community use)
• Stacking with a growth hormone releasing hormone analog
• Investigational stroke treatment alongside a second drug

Two or three times daily in community practice

Community practice is 100 to 300 mcg under the skin two or three times a day. One clinic chart review used 100 mcg three times a day. That review covered only 14 men, ran no control group, and gave two other peptides alongside it. The rest of the figures come from forum protocols catalogued in a review. The idea that about 100 mcg saturates the pituitary is false. Growth hormone rose steeply across every dose tested and was still climbing at the highest one. That 100 mcg figure matches the standard diagnostic dose given into a vein rather than any ceiling.

Blood levels fall in two stages. The fast stage has a half-life of about 8 minutes and the slow one about 2.5 hours. Those figures come from nine healthy men given it into a vein. The doses used were 100 to 400 mcg per kg. That works out to 7 to 28 mg for an adult and is far above anything people inject. Nobody has measured it after an injection under the skin. The commonly repeated figure of 15 to 20 minutes traces to no study.

• Increased hunger
• A doubling of cortisol and prolactin at about 70 mcg into a vein with no rise at the lower doses tested
• A small rise in ACTH
• More light sleep with deep sleep unchanged
• Lower thyroid stimulating hormone during a long infusion
• Generally no adverse effects reported in the small human studies

GHRP-6 activates the ghrelin receptor on the pituitary and in the hypothalamus. The pituitary then releases its own growth hormone. That raises IGF-1 from the liver. It is often said to work by lifting the brain's brake on growth hormone. The one human experiment built to test that idea found otherwise. How much brake is present changes the size of its effect. It does not work by lowering that brake. It also switches on appetite neurons in the hypothalamus. Blocking one of those receptors abolishes the feeding effect in rats. It also binds a scavenger receptor called CD36. Chemists have modified GHRP-6 into versions that keep the CD36 activity and lose the growth hormone release. Those versions were tested in mice for artery disease. What CD36 contributes to GHRP-6 itself in a person has never been studied.

As a single compound GHRP-6 has been given to people in published studies only a handful of times. The largest was nine healthy men and it measured blood levels rather than any benefit. There is no published human study of it injected under the skin at all. A Cuban group has taken it furthest. That work combined it with a second drug and tested only stroke. The combination reached a 188-person trial that missed its main goal. A benefit appeared only in the most severe cases. The heart and wound-healing uses it is known for have never been tested in a person. Animal safety studies for the heart product were still being published in 2025. That is work that normally comes before the first human dose.

• It is banned in sport at all times and is named individually on the prohibited list
• No published human study has used the injection under the skin that people actually give themselves
• Cortisol and prolactin roughly double at about 70 mcg into a vein and that is inside the range people inject
• Growth hormone and IGF-1 drive cell growth so it is not for anyone with a current or past cancer
• Avoid it in pregnancy and breastfeeding since no human data exist
• Black market products have been found containing modified versions of this peptide rather than the peptide itself