Each week we summarize new research on longevity, peptides, and regenerative medicine in plain language. Every summary includes the studies it is based on so you can read the source yourself. This week covers three topics.
Urolithin A: a gut compound studied for muscle and mitochondria
- Urolithin A is made by gut bacteria from compounds in foods like pomegranates, berries, and walnuts. Not everyone’s gut makes it well.
- Randomized human trials using 500 to 1000 mg a day have shown small improvements in muscle strength and in markers of mitochondrial health, mostly in older or middle-aged adults.
- It works by helping cells clear out damaged mitochondria, a process called mitophagy. No human study shows it extends lifespan.
Mitochondria are the parts of the cell that make energy. As we age, worn-out mitochondria build up. Urolithin A appears to help the body recycle them, which is why it is studied for muscle and energy.
Because many people’s gut bacteria do not produce much urolithin A from food, it is sold as a supplement (one brand is Mitopure). Randomized trials in middle-aged and older adults have reported modest gains — on the order of a roughly 10 percent improvement in some muscle-strength measures — plus better mitochondrial markers and endurance. A trial in frail older adults finished in 2025.
The effects are real but small, and they are about muscle function and cell health, not lifespan. Claims that it “reverses aging” go beyond what the human data show.
- Singh A, et al. "Urolithin A improves muscle strength and mitochondrial health markers in a randomized trial in middle-aged adults." Cell Reports Medicine, 2022. cell.com
- "Targeting aging with urolithin A in humans: a systematic review." Ageing Research Reviews, 2024. sciencedirect.com
Collagen peptides: what the trials show for skin and joints
- Collagen peptides are short protein fragments, usually made from cow or fish collagen, taken as a powder or drink.
- A 2025 review that pooled 23 randomized trials found collagen supplements improved skin hydration, elasticity, and wrinkles.
- Separate randomized trials found that daily collagen peptides reduced activity-related knee and joint pain. Effects are modest and build over several weeks.
Collagen is the main structural protein in skin, tendons, and cartilage. “Peptides” just means it has been broken into small pieces so the body can absorb it. Once absorbed, the fragments may signal the body to make more of its own collagen.
For skin, a 2025 meta-analysis in a major medical journal combined 23 randomized, placebo-controlled trials and found consistent improvements in hydration, elasticity, and the look of wrinkles, often after 8 to 12 weeks. For joints, randomized trials have shown lower activity-related pain in both younger active adults and people with knee osteoarthritis.
This is one of the better-studied supplements, and it has a strong safety record. Still, the benefits are modest, not dramatic, product quality varies, and collagen is not a substitute for treatment of a diagnosed joint problem.
- "Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials." The American Journal of Medicine, 2025. amjmed.com
- "Efficacy and safety of low-molecular-weight collagen peptides in knee osteoarthritis: a randomized, double-blind, placebo-controlled trial." Frontiers in Nutrition, 2025. frontiersin.org
Cellular reprogramming: the first human trial gets a green light
- “Partial reprogramming” tries to reset cells to a younger state without turning them into stem cells.
- In animals it has rejuvenated tissues and, in some models, extended lifespan. The length of treatment seems to matter.
- In 2026 the FDA cleared the first human trial of a reprogramming therapy, called ER-100, aimed at an age-related eye disease.
Every cell carries a kind of software layer that controls which genes are switched on. That layer drifts with age. Reprogramming uses a set of factors (often called Yamanaka factors) to reset it. “Partial” means stopping early, before a cell loses its identity and becomes a stem cell.
In animals, brief reprogramming has restored function in nerves, eyes, and other tissues and extended lifespan in some models, with longer courses generally working better than very short ones. In 2026 this moved a major step toward people: the FDA cleared an investigational new drug application for ER-100, a gene therapy designed to rejuvenate retinal cells in serious age-related eye disease.
This is exciting but genuinely first-generation. Pushing reprogramming too far carries a theoretical cancer risk, and a cleared trial is the beginning of testing, not proof that it works. It is a space to watch, not a treatment to seek out.
- "The epigenetic rejuvenation promise: partial reprogramming as a therapeutic strategy for aging and disease." Ageing Research Reviews, 2026. sciencedirect.com
- "FDA clears first-in-human trial of a partial epigenetic reprogramming therapy (ER-100)." Life Biosciences announcement, 2026. lifebiosciences.com