Glutathione

DSIP, or delta sleep-inducing peptide, is a small naturally occurring nonapeptide (sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) first isolated in the 1970s from the blood of sleeping rabbits. As the name suggests, it was named for its ability to promote delta-wave (deep, slow-wave) sleep in animals. Despite five decades of study it has no regulatory approval and the human evidence for it as a sleep aid is weak and inconsistent.

Humanin is a 24-amino-acid peptide encoded inside mitochondrial DNA (in the 16S rRNA gene), discovered in 2001 and named for its ability to protect human neurons from Alzheimer-related cell death. It was the first member of the mitochondrial-derived peptide family and is studied mainly for neuroprotection, cell survival, and metabolic and age-related disease. The honest status: it has the deepest preclinical evidence base of any mitochondrial peptide, but human therapeutic trials are essentially absent.

NAD+ precursors are not peptides. They are small molecules, mainly nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), that the body converts into NAD+, a coenzyme every cell needs to make energy and run repair enzymes. NAD+ falls with age, so these precursors are sold as anti-aging and metabolic supplements. Human trials confirm they reliably raise blood NAD+ levels, but clear proof of real health benefits in people is still missing.

SS-31 (sequence D-Arg-Dmt-Lys-Phe-NH2), known generically as elamipretide and sold as FORZINITY, is a synthetic tetrapeptide that homes in on the energy-producing machinery inside your cells. It works by binding cardiolipin, a fat unique to the inner mitochondrial membrane, to help mitochondria run cleaner and make more ATP with less oxidative damage. This is the rare research peptide with a real regulatory finish line: the FDA granted it accelerated approval in September 2025 for Barth syndrome, though it has failed several other major trials.

FOXO4-DRI is an experimental senolytic peptide, meaning it is designed to kill off worn-out 'zombie' cells (senescent cells) while leaving healthy ones alone. It comes from a single influential 2017 mouse study and is engineered with a clever stability trick. It has never been tested in a human clinical trial, so anything beyond 'promising in mice' is speculation.

Vesilute is marketed as a Khavinson-style short peptide bioregulator aimed at the urinary bladder and lower urinary tract. Vendor sources cannot even agree on its sequence: some list a Glu-Asp dipeptide, others a Lys-Glu-Asp tripeptide. There are no approvals and, importantly, no peer-reviewed studies published specifically on a peptide called Vesilute, so almost everything written about it is extrapolated from the broader bioregulator family rather than direct evidence.