Peptide library / Bones & muscles / Irisin
Irisin
A hormone-like protein released by muscle during exercise, with a contested role in people.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Browning of fatAnimals
- Bone strengthAnimals
- Brain healthAnimals
How it is thought to work
Irisin is cut from a membrane protein in muscle and was reported to turn white fat into more energy-burning brown-like fat in mice.
What the evidence shows
The 2012 discovery was exciting, but debate continues over whether human irisin is active at physiological levels.
Safety and unknowns
Safety in people has not been tested.
Regulatory status
Not approved. A research tool.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
More in Bones & muscles
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IGF-1 LR3
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General information, not medical advice. Do not buy or inject unregulated peptides.