What does the research actually say?

Mitochonic Acid 5 (MA-5) is a synthetic indole compound studied for mitochondrial disease. It binds mitofilin/MIC60, a protein involved in organizing the inner mitochondrial membrane. Human development has reached phase I safety testing; clinical benefit remains unproven.

Urolithin B is a gut microbial metabolite of dietary ellagitannins, studied for muscle growth and protection against muscle wasting. It increased muscle size and reduced denervation-induced atrophy in mice. A 2026 study found distinct effects on gene expression in cultured human muscle cells, but did not test a supplement in people. Its muscle evidence remains preclinical; it is not interchangeable with urolithin-a.

Urolithin A is not something plants make. It is what some people's gut bacteria make out of the ellagitannins in pomegranates, walnuts and berries, and only about one person in seven produces enough of it to show up in blood without a supplement. Synthetic urolithin A was identified as the first natural compound to induce mitophagy — the pathway that clears worn-out mitochondria. Four randomized trials have now tested it in people. The two muscle trials both missed their primary endpoint and both reported gains on secondary measures; a 2025 trial found changes in T-cell composition and metabolism; and a trial in trained runners found no performance benefit.

ISRIB is an experimental small molecule that activates eIF2B, a protein-synthesis regulator, and counters part of the integrated stress response. Short courses improved memory in aged and brain-injured mice, sometimes weeks after treatment ended, but Alzheimer's-model results are mixed. A 2025 review found no published human trials of ISRIB; self-reported use does not establish a clinical benefit or a safe dose.

ACD856 is an experimental oral drug from the Swedish company AlzeCure Pharma. It is a positive allosteric modulator of the Trk receptors: it does not replace BDNF or NGF but makes TrkA, TrkB and TrkC respond more strongly to them. In mice and rats it reversed drug-induced and age-related memory deficits and shortened immobility in the forced swim test. In people it has only been through phase 1: single doses up to 150 mg and seven days at up to 90 mg a day were well tolerated in healthy volunteers, it reached the cerebrospinal fluid, and it shifted the resting EEG, but no published trial has tested whether it improves memory or mood. Every published study comes from the developer.