Hexarelin: A More Stable Growth Hormone-Releasing Peptide That Works in Both Young and Adult Rats | Research

The takeaway

Hexarelin effectively stimulated GH secretion in both infant and adult rats through a pathway independent of GHRH, with improved chemical stability over earlier peptides.

Works at all ages
Hexarelin stimulated GH in both infant and adult rats, unlike some peptides that lose effectiveness with age

What the researchers found

Hexarelin effectively stimulated growth hormone secretion in both infant and adult rats through a non-GHRH pathway.

Why it matters

Growth hormone releasing peptides are used to boost natural GH production. Hexarelin's improved chemical stability made it a practical candidate for research and clinical development.

How the study worked

Researchers tested hexarelin in conscious 10-day-old and adult rats via intravenous and subcutaneous injection. They measured growth hormone levels and compared hexarelin to GHRP-6. They also tested it in rats with damaged GHRH neurons.

What this study cannot tell us

Animal study in rats. Doses and responses in rats do not directly predict human dosing or effects. Long-term safety and efficacy not assessed.

How to read the evidence

Moderate — animal study demonstrating effectiveness in two age groups. Strengthened by comparison with established GHRP analogs.

When this study was published

Published in 1994 (32 years ago). Hexarelin has since been tested in human clinical trials.

The bigger picture

GH-releasing peptides evolved from research tools into clinical candidates. Hexarelin's improved stability addressed a key practical limitation, bringing peptide GH therapy closer to real-world use.

Questions still open

How does hexarelin compare to MK-677 in clinical settings?
What are the long-term effects of chronic hexarelin use?

Common questions

What is hexarelin?

Hexarelin is a synthetic peptide that stimulates the body to release its own growth hormone. It's a modified version of GHRP-6 with better chemical stability, meaning it lasts longer and is more practical to use.

How is it different from HGH injections?

Instead of injecting synthetic growth hormone directly, hexarelin triggers the body's own pituitary gland to release natural GH in its normal pulsatile pattern. This is considered more physiological and potentially safer.

Read the original research

GH-releasing activity of Hexarelin, a new growth hormone releasing peptide, in infant and adult rats.

Life sciences, 54(18), 1321-8

View on PubMed ↗

Citation

Deghenghi, R; Cananzi, M M; Torsello, A; Battisti, C; Muller, E E; Locatelli, V. (1994). GH-releasing activity of Hexarelin, a new growth hormone releasing peptide, in infant and adult rats.. Life sciences, 54(18), 1321-8.