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: prohibited at all times (S0). [1]
2026 List, S0, printed page 4 · 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 mechanism
Reldesemtiv, formerly CK-2127107, is a fast skeletal-muscle troponin activator. It was developed to increase the muscle contractile response to calcium, rather than to act as an anabolic steroid. [2]
Physiological studies versus clinical benefit
An early healthy-volunteer investigation included a 16-man crossover experiment measuring electrically evoked lower-leg muscle force. The force response demonstrated pharmacological activity, not improved sporting performance or patient function. The research had Cytokinetics and Astellas support and disclosed company-related author interests. [2]
The phase 3 COURAGE-ALS trial compared reldesemtiv with placebo in people with amyotrophic lateral sclerosis. It stopped early for futility and did not demonstrate slowing of decline on the ALS Functional Rating Scale–Revised. Early termination and missing observations complicate the size of the estimated effect. This negative result should not be rewritten as established ALS benefit. [3]
Health and evidence limitations
Liver-enzyme elevations were more frequent with reldesemtiv in COURAGE-ALS, sometimes leading to interruption or discontinuation. The trial disclosed company funding and sponsor involvement in design, analysis and publication. ALS trial findings do not establish safety in healthy athletes or characterize products sold outside the study. [3]
What remains uncertain
- No current marketing authorization or product composition was independently verified.
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 · official_full_text_relevant_sections
Effective date; S0 printed page 4; S2 printed pages 7–8
- Andrews et al. 2018: CK-2127107 in healthy participants ↗Accessed 2026-11-10 · full_text_relevant_sections
Muscle & Nerve; DOI 10.1002/mus.26017; methods, results and disclosures
- Shefner et al. 2025: COURAGE-ALS reldesemtiv trial ↗Accessed 2026-11-10 · full_text_relevant_sections
JAMA Neurology; methods, results, safety, limitations and sponsor role
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.