What are the side effects of Follistatin 344?
The most commonly reported Follistatin 344 side effects are limited human safety data, theoretical: cardiac and tendon issues with chronic strong myostatin suppression, injection-site irritation. Most are mild and tend to be dose dependent. It is generally avoided with anyone risk-averse to limited human data. Human clinical evidence for Follistatin 344 is limited, so this reflects reported and observed effects, not a complete safety profile.
Reported Follistatin 344 side effects
- Limited human safety data
- Theoretical: cardiac and tendon issues with chronic strong myostatin suppression
- Injection-site irritation
Who should avoid it
- Anyone risk-averse to limited human data
- Pregnancy / nursing
- Active malignancy
References
- Long-term enhancement of skeletal muscle mass and strength by single gene administration of myostatin inhibitors — Haidet AM, Rizo L, Handy C, et al. (incl. Mendell JR, Kaspar BK), PNAS, 2008
- Follistatin gene delivery enhances muscle growth and strength in nonhuman primates — Kota J, Handy C, Haidet AM, et al. (incl. Kaspar BK), Science Translational Medicine, 2009
- A phase 1/2a follistatin gene therapy trial for Becker muscular dystrophy — Mendell JR, et al., Molecular Therapy, 2015 (NCT01519349)
Pepdex is an editorial reference, not medical advice. Peptides vary in legal and approval status by country, many are research compounds without full human safety data. Talk to a qualified clinician before starting anything.
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Last updated 2026-06-06.