Hexarelin

Key points

• Hexarelin is a six amino acid peptide that acts on the growth hormone secretagogue receptor to release growth hormone.
• It also binds a receptor called CD36 in heart tissue, which is separate from growth hormone and is the basis of cardiac research interest.
• Its growth hormone effect blunts with repeated or continuous dosing, so tolerance is a known issue.
• It has no UK marketing authorisation, and growth hormone releasing peptides are prohibited in sport.

Quick facts

What it is

Growth hormone releasing peptide, 6 amino acids

Also studied for

Heart tissue effects (via CD36), in animals

UK status

Not a licensed medicine; sold for research use

Human evidence

Early pharmacology only

In sport

On the WADA Prohibited List

How it works

Hexarelin binds the growth hormone secretagogue receptor in the pituitary and hypothalamus, prompting a pulse of growth hormone. It also acts on CD36 in the heart, which in animal studies has been linked to protecting heart tissue, an effect separate from growth hormone. With steady dosing the growth hormone response fades, which is why cycling is often discussed.

What the evidence shows

Human data is limited to early pharmacology, mainly on growth hormone release. The cardiac and organ protection work is in animals and the laboratory, not human trials. There is no settled dose and no long term human safety data.

What it does not settle

• The heart and organ effects have not been tested in people.
• Long term safety, and effects on cortisol, prolactin and insulin, are not established.
• There is no validated human dose.

Side effects

Common

• Increased appetite, water retention, and injection site reactions.
• A temporary rise in cortisol and prolactin.

Less common but serious

• Possible low blood sugar, and signs of too much growth hormone such as joint pain or swelling.
• Because there is no licensed product, the dose, purity and contents of material bought online cannot be verified.

Report any suspected side effect through the MHRA Yellow Card scheme.

UK legal status and access

Hexarelin has no UK marketing authorisation, so it is not a licensed medicine and is not offered by registered clinics or pharmacies. It is sold online labelled for research use. Genuine growth hormone deficiency is diagnosed and treated with licensed medicines under specialist care.

Common questions