Kinetin is a plant hormone. While its specific mechanisms have not been elucidated, it has been observed to promote growth and have anti-senescence effects in plants. It is a powerful natural antioxidant with effects in protecting DNA and protein from oxidative damage. In human fibroblast cell culture, even very low levels (ppm) delay the onset of changes associated with cell aging, e. g., appearance of lipofuscin, appearance of multinucleate cells, and microtubule disorganization (64).
In three reported clinical tests (10-24-week duration, n = 30-98), topical 0.1% kinetin was reported to improve several aging skin problems, such as wrinkling, poor texture, and hyperpigmentation (64). All of these studies apparently did not involve a placebo control,
but rather were comparisons (dermatologist grading and self-assessment) of treatment effects versus baseline. The 0.1% dose is well tolerated by the skin, with no significant irritation issues described.