SS-31, also called elamipretide, interacts with cardiolipin in mitochondrial membranes. This gives researchers a way to investigate energy-related cell function. However, MMPOWER-3, a randomized trial in 218 people with primary mitochondrial myopathy, did not show improved walking distance or fatigue at 24 weeks compared with placebo. A mechanism does not guarantee symptom improvement.

A small Barth syndrome trial did not meet its primary outcomes during the randomized phase, while an open-label extension reported improvements in functional measures. In 2025, the US FDA granted accelerated approval to the clinical medicine Forzinity for muscle strength in a defined Barth syndrome population. That decision does not establish general energy or anti-ageing benefits for a research vial.

SS-31 is studied for mitochondrial membrane interactions, whereas MOTS-c research includes metabolic signalling. Their shared mitochondrial theme does not make them interchangeable or demonstrate benefit from combining them. MOTS-c performance experiments in mice and human measurements around exercise answer different questions from SS-31 clinical trials in people with defined diseases.