SS-31

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.

Glutathione is the body's main intracellular antioxidant, a tripeptide of glutamate, cysteine, and glycine (often written GSH). It is sold as oral, IV, topical, and inhaled products and marketed for everything from detox and immune support to skin lightening, but its real, evidence-backed role is as a redox buffer that neutralizes oxidative stress and supports liver detoxification. Some clinical evidence exists for specific uses, while many popular claims, especially IV skin whitening, rest on weak or risky data.

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.

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.

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.