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What it is
Hexarelin is a synthetic hexapeptide developed from the growth hormone-releasing peptide family. It activates the ghrelin receptor and can prompt a rapid release of growth hormone from the pituitary.
Human studies are small and mostly date from the 1990s. They measured acute hormone responses, short-term responsiveness, or immediate cardiovascular changes rather than lasting improvements in muscle, recovery, body composition, or health. Hexarelin has no FDA-approved medical use.
What people research it for
Produces a strong short-term growth hormone response
Human studiesA placebo-controlled rising-amount study in 12 healthy men found a rapid, amount-related growth hormone increase that peaked at about 30 minutes and returned to baseline within four hours.
Retained responsiveness during brief studies
Early human dataTwo seven-person studies in older adults found that repeated intranasal or oral exposure over 8 or 15 days did not remove the acute growth hormone response. IGF-1 did not increase significantly.
Produced an acute cardiac signal
Early human dataIn seven male volunteers, hexarelin briefly increased left-ventricular ejection fraction without changing blood pressure or heart rate. This was an immediate laboratory result, not evidence of long-term clinical benefit.
Shows age-dependent endocrine effects
Human studiesComparative studies found a smaller growth hormone response in older adults, while combined stimulation could partly restore it. This supports endocrine mechanism research rather than anti-aging claims.
How it works
Hexarelin activates the growth hormone secretagogue receptor in the hypothalamus and pituitary. The response interacts with natural GHRH signaling, and older adults generally show a smaller growth hormone rise than younger adults.
The receptor is also found outside the pituitary. A seven-person study reported a brief increase in left-ventricular ejection fraction, but that isolated acute finding does not establish a heart treatment. Hexarelin also raised prolactin, ACTH, and cortisol in human challenge studies, so its action is not selective for growth hormone.
What the research actually shows
A double-blind, placebo-controlled rising-amount study enrolled 12 healthy men. Growth hormone peaked about 30 minutes after intravenous hexarelin and returned to baseline within 240 minutes. Mean peak concentrations rose from 3.9 ng/mL with placebo to 26.9, 52.3, and 55.0 ng/mL across the three tested amounts.
A comparative study in six young adults found that hexarelin and GHRP-2 produced similar strong growth hormone responses. Both also increased prolactin, ACTH, and cortisol. The ACTH and cortisol response was similar to the response produced by a corticotropin-releasing hormone challenge in that experiment.
Age changed the response. A study of 13 young and 16 older men found that the growth hormone response to hexarelin was substantially lower in the older group. Adding GHRH or arginine increased the response, showing that pituitary capacity remained but the intact signaling system differed with age.
Short-term repeated exposure was tested in seven older adults given intranasal hexarelin for eight days and seven older women given oral hexarelin for 15 days. Acute growth hormone responsiveness was maintained, but serum IGF-1 did not rise significantly. The studies were too small and brief to establish body-composition or health outcomes.
In seven male volunteers, intravenous hexarelin increased left-ventricular ejection fraction from 64.0% to 70.7% for up to about 60 minutes, while recombinant growth hormone did not. Blood pressure and heart rate were not significantly changed. This single acute experiment does not establish treatment of heart disease.
Most claims about heart protection come from animal or isolated-heart work, not clinical outcomes trials. No robust randomized human trial was found showing that hexarelin improves strength, lean mass, recovery, cardiovascular disease, or healthy aging.
Handling & storage
Storage at a glance
Vendor consensus- Lyophilized
- below -18°C
- about 3 weeks at room temperature according to the checked technical pages
- Keep desiccated and sealed.
- Reconstituted
- 4°C
- Use within 2 to 7 days
- Technical supplier guidance, not a universal pharmaceutical expiry.
- Light
- Protect from moisture and unnecessary light exposure.
- Room temperature
- Sealed dry material is listed as stable for about 3 weeks.
- Reconstitution
- product-specified sterile diluent
- Use the exact product instructions and avoid repeated freezing and thawing.
Basis: Vendor consensus. Sources: ProSpec hexarelin technical product page, RayBiotech hexarelin technical product page
Two checked technical suppliers agree that lyophilized hexarelin should be kept desiccated below -18°C for long-term storage. Both describe the sealed dry material as stable for about three weeks at room temperature, which is a shipping and handling allowance rather than a universal expiry.
The same technical pages agree on 4°C after reconstitution and a 2 to 7 day refrigerated window. They also advise frozen single-use aliquots for longer laboratory storage and avoiding repeated freezing and thawing. These are supplier instructions, not an independent finished-vial stability study.
Safety & cautions
Human studies show that hexarelin can raise prolactin, ACTH, and cortisol as well as growth hormone. Possible concerns include flushing, appetite changes, fluid retention, glucose disruption, and effects linked to excessive growth hormone or IGF-1 signaling. Small acute studies cannot define uncommon or long-term harms.
Hexarelin is not FDA approved. Research products can vary in identity, purity, fill amount, sterility, and endotoxin burden. Safety has not been established for pregnancy, children outside supervised research, cancer, diabetes, pituitary or adrenal disorders, heart disease, or long-term use.
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Frequently asked questions
Is hexarelin FDA approved?
No. Hexarelin has no FDA-approved medical use.
What does hexarelin do?
It activates the ghrelin receptor and can produce a brief growth hormone pulse. It can also affect prolactin, ACTH, and cortisol.
Is hexarelin proven to build muscle?
No robust randomized human trial was found showing improved lean mass, strength, or athletic recovery.
Does hexarelin stop working quickly?
Two very small studies in older adults found that acute growth hormone responsiveness persisted over 8 or 15 days, but they do not answer questions about longer exposure.
Does hexarelin protect the heart?
A seven-person study found a brief increase in ejection fraction, while most protective findings come from animal research. That is not evidence of a heart treatment.
How should laboratory hexarelin be stored?
Checked technical sources agree on dry storage below -18°C and 4°C for 2 to 7 days after reconstitution, with product-specific instructions taking priority.
Sources
- Placebo-controlled hexarelin growth hormone response study
- GHRP-2 and hexarelin comparative hormone study
- Hexarelin response in younger and older adults
- Short-term intranasal and oral hexarelin study
- Acute cardiovascular and hormonal effects in humans
- ProSpec hexarelin technical product page
- RayBiotech hexarelin technical product page
Last reviewed September 17, 2026. This guide is educational and research-focused, not medical advice. Hexarelin products referenced on PeptidePub are sold by third parties as materials for laboratory research use only, not for human or animal consumption.
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