SS-31 Side Effects: Safety Signals and Warnings
SS-31 safety concerns are compound-specific. The main listed side effects are Injection-site reactions are the most common adverse reactions, Headache, and Mild gastrointestinal symptoms. The main warning signals are Accelerated approval is limited to Barth syndrome in patients weighing at least 30 kg, Confirmatory clinical benefit is still required, and The randomized pivotal study did not meet its primary walk-distance or fatigue endpoints.
Direct Answer
Elamipretide is now FDA-approved, but only for improving muscle strength in Barth syndrome patients who weigh at least 30 kg, under accelerated approval. The randomized pivotal trial missed its primary endpoints, and evidence does not support extending the result to longevity, heart failure, or general mitochondrial enhancement.
- Evidence grade
- Level B
- Research status
- FDA Approved
- Category
- Anti-Aging & Longevity
- Evidence context
- Approved Barth-syndrome use and research on cardiolipin-targeted mitochondrial biology
Reported Side Effects
- Injection-site reactions are the most common adverse reactions
- Headache
- Mild gastrointestinal symptoms
- Hypersensitivity reactions and eosinophilia have been reported
Warnings
- Accelerated approval is limited to Barth syndrome in patients weighing at least 30 kg
- Confirmatory clinical benefit is still required
- The randomized pivotal study did not meet its primary walk-distance or fatigue endpoints
- Monitor for hypersensitivity and clinically significant injection-site reactions under the approved label
Known or Plausible Interactions
- Other mitochondrial-targeted agents
- Statins (may have complementary mitochondrial effects)
- Drugs metabolized by mitochondrial enzymes
Regulatory Context
FDA granted Forzinity (elamipretide) accelerated approval on September 19, 2025 to improve muscle strength in adults and pediatric patients with Barth syndrome who weigh at least 30 kg. It remains investigational for heart failure, aging, kidney injury, and other mitochondrial conditions. Continued approval for Barth syndrome may depend on a confirmatory trial.
Evidence Snapshot
| Evidence grade | Level B |
|---|---|
| Research status | FDA Approved |
| Best supported outcomes | Mitochondrial Function (Level B), Barth Syndrome Muscle Strength (Level B), Heart Failure (Level B), and Exercise Capacity (Level B) |
| Primary citation count | 6 |
| Last reviewed | 2026-08-27 |
Quick Answers
What are the side effects of SS-31?
SS-31 safety concerns are compound-specific. The main listed side effects are Injection-site reactions are the most common adverse reactions, Headache, and Mild gastrointestinal symptoms. The main warning signals are Accelerated approval is limited to Barth syndrome in patients weighing at least 30 kg, Confirmatory clinical benefit is still required, and The randomized pivotal study did not meet its primary walk-distance or fatigue endpoints.
What is the evidence level for SS-31?
SS-31 is rated Level B. Its current research status is FDA Approved.
What is SS-31 best known for?
Approved Barth-syndrome use and research on cardiolipin-targeted mitochondrial biology.
Where can I read the full SS-31 evidence review?
The full evidence review is available at https://examinepeptides.com/library/ss-31.
Related Guides
How to Cite This Page
ExaminePeptides. "SS-31 Side Effects: Safety Signals and Warnings." Last reviewed 2026-08-27. https://examinepeptides.com/answers/ss-31-side-effects-safety/
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