Checked 2026-11-10. Independent clinical review has not been completed. WADAFUK is independent of WADA and does not provide medical advice or an individual anti-doping determination.
Prohibited at all times
2026 S4.3: prohibited at all times. Non-Specified. [1]
S4.3 · 2026 rules apply from 1 January 2026. Any 2027 material below concerns future rules from 1 January 2027; it is not current clearance.
Identity and human research
Follistatin-related gene transfer and injections of recombinant follistatin protein are different interventions. A six-person Becker muscular dystrophy study delivered an AAV vector carrying FS344 into muscle. Some walking-test outcomes improved, but the small uncontrolled study cannot establish efficacy or the safety of retail protein injections. [2]
- The trial studied a particular gene-transfer intervention, not a consumer supplement; gene-transfer methods also require separate M3 consideration.
Product identity and exposure
Analytical research found inconsistent contents in products sold as follistatin, including non-native tagged protein and other growth-related peptides. The linked erratum corrects misplaced product-information columns. The retained conclusion is qualitative: a label did not reliably specify the protein formulation. [3] [4]
- Market-paper abstract plus erratum reviewed. Selected historical products do not establish present prevalence or safety.
Check the sources.
These are concise editorial paraphrases of selected sources, not a systematic review or a reproduction of source tables. Access depth is shown for each reference; an abstract-only check cannot resolve details found only in a full paper.
- WADA 2026 Prohibited List ↗Accessed 2026-11-10 · Relevant official full-text sections opened
Printed pp. 3, 9–12: introduction, S3, S4 and S5 as applicable
- Follistatin gene therapy in Becker muscular dystrophy ↗Accessed 2026-11-10 · Relevant document text opened
Relevant cited sections
- Detection of black market follistatin 344 ↗Accessed 2026-11-10 · Primary-study abstract and metadata
Abstract and bibliographic record
- Correction: Detection of black market follistatin 344 ↗Accessed 2026-11-10 · Relevant document text opened
Relevant cited sections
Check the current official WADA List and the relevant anti-doping authority for your sport, product, route and circumstances. Do not stop or change necessary treatment based on this page. Ask a qualified clinician about health decisions. Missing evidence does not establish safety.