Hexarelin
GH-releasing hexapeptide
A potent growth hormone secretagogue with an unexpected cardiac angle — direct effects on heart tissue that are independent of growth hormone. Desensitisation limits its use.
- Category
- Growth & Performance
- Half-life
- Approximately 55 minutes in reported summaries
- Cycle length
- Not established; desensitisation occurs with continuous use
- Level
- advanced
Overview
Hexarelin is the most potent of the growth hormone secretagogue hexapeptides in common research use, and the one with the most unusual secondary story: several studies reported improvements in cardiac performance that could not be explained by its growth hormone effect, leading to interest in its direct action on heart tissue. Its downside has always been desensitisation. Continuous use blunts the response quickly, and it raises cortisol and prolactin more than comparable compounds. Clinical interest in it has largely been cardiac research rather than body composition.
How it works
Hexarelin is a synthetic hexapeptide that activates the ghrelin receptor, GHS-R1a, producing growth hormone release and amplifying GHRH signalling. What separates it from its relatives is evidence that it also binds CD36 on cardiac tissue, which is the basis for the reported effects on heart contractility that appear even when growth hormone release is blocked.
Reported benefits
- Potent growth hormone release in human studies
- Cardiac performance effects observed independently of growth hormone in some studies
- Interest in cardiac and ageing research settings
- Effects appear rapidly after dosing
Reported benefits describe what the published literature and user reports suggest — not a promise of outcome for any individual.
Dosing reference
Studies in adults have used roughly 100 to 200 mcg per dose, often two to three times daily, and cardiac research used similar ranges. There is no approved product or approved dose.
Hexarelin loses effect quickly with continuous dosing — receptor desensitisation is well described — which historically led to intermittent schedules rather than daily use. Cortisol and prolactin rises are more pronounced than with GHRP-2.
Community-reported: 100–200 mcg one to three times daily, rarely continued beyond four weeks at a time because of reported tolerance.
These figures are what people report using in public communities. They have not been studied, verified or checked against certificates of analysis, and they are not a recommendation, a prescription or a target to aim for.
Where the reported amounts come from
Amounts are reproduced for education only. Doses from trials cannot be assumed to suit anyone else, and community-reported amounts are frequently wrong. Self-administering unapproved compounds carries serious risk.
The research picture
Human studies demonstrate that hexarelin produces one of the strongest growth hormone responses of the secretagogue family, with corresponding rises in cortisol and prolactin. A separate body of work in older adults and in people with impaired cardiac function reported improvements in measures of cardiac performance, and mechanistic studies attributed part of this to CD36 receptor binding rather than to growth hormone. Neither line produced an approved therapy. The cardiac findings were intriguing and small; the growth hormone findings describe a hormone response rather than a benefit. Tolerance with frequent dosing remains a practical limitation that no protocol has solved.
Preclinical & non-clinical data
Studied in cardiac tissue: it has documented effects on cardiac contractility through a CD36-dependent mechanism. That work is why cardiac safety questions follow the compound, and why its reported tolerance curve looks different from the ghrelin-receptor agonists.
Non-clinical data comes from cells and animals unless stated otherwise. It answers whether a compound is worth studying in people — not whether it is safe or effective in them.
What users report
Users describe it as the strongest and shortest-lived of the secretagogues: a pronounced effect at first, then tolerance within weeks, so it appears in short bursts rather than long runs. More than any other compound in this category, these accounts mention heart-rhythm awareness, palpitations and blood-pressure changes — consistent with its known cardiac activity — and that is the caution people repeat to each other in the threads.
Where these reports come from
These are unverified personal accounts collected from public sources. They are not evidence of effectiveness or safety, they have not been independently checked, and they are not a recommendation to use anything described.
Possible side effects
- Flushing, tingling and warmth
- Cortisol and prolactin increases
- Headache and lightheadedness
- Rapid loss of effect with frequent dosing
- Increased appetite
Safety notes
Continuous use causes rapid receptor desensitisation, so escalating doses produce more side effects without proportionate growth hormone response. Cortisol and prolactin elevation is more marked than with related compounds. Contraindicated in active malignancy and pituitary disease; no long-term human safety data.
Stacking
Sometimes combined with a GHRH analogue. Because desensitisation is the limiting factor for hexarelin, stacking does not overcome tolerance and leaves no way to attribute effects.
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Tesamorelin
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