Trade name N6-furfuryladenine, a plant hormone responsible for cell division. As a “natural” skin-care ingredient, it is promoted primarily as having been clinically proven to reduce the signs of aging, improve sun damage, reduce surfaced capillaries, and offer many other skin benefits of particular interest to aging baby boomers. There is a good deal of research on kinetin when it comes to plants or in test tubes (in vitro), with cells, and even on flies, but there is no published research on kinetin’s topical effect, either on animal or human skin (Source: Dermatologic Clinics
, October 2000, pages 609–615).
Although there are two unpublished clinical studies responsible for much of the attention kinetin is getting, both were sponsored by Senetek, the company that licenses the use of kinetin. On a closer look, according to MedFaq.com (a now-defunct Internet source that evaluated the legitimacy of medical research), the data are far less convincing than Senetek wants you to know. These studies, paid for by Senetek, were both performed by Dr. Jerry L. McCullough, Professor of Dermatology, University of California, Irvine. According to MedFaq, “The first study was well-designed—there was a control group and [it was done] double-blind…. After 24 weeks, a good response was noted in 30% of the subjects treated with kinetin … [but] there was no statistically significant difference between the people taking kinetin and the people just getting the placebo.” Another study was then performed that did not use a placebo control group, but in which everyone was using a product that contained some amount of kinetin. Not surprisingly, in this protocol the results for skin were much better. “Essentially all of the subjects reported improvement after 24 weeks …” regardless of how much kinetin the product contained. As MedFaq states, “This outcome could also have a variety of causes unrelated to kinetin: It could reflect an improvement over time, a change across seasons, the subjects’ enthusiasm, or it could have been caused by the cream or lotion the kinetin is in. In the first study, all of the subjects followed ‘a standard skin-care regimen consisting of a gentle-skin cleanser and daily use of sunscreen.’ If that regimen was followed in the second experiment, it too might explain the improvement.”
Recent studies indicate that kinetin can help increase cell differentiation (turnover rate) and that it works best in the presence of calcium as an inducing agent, but that combination is not what is being used in skin-care products that contain kinetin (Source: Annals of the New York Academy of Sciences, May 2006, pages 332–336). Kinetin may have benefit as a cell-communicating ingredient, but this has been demonstrated only in vitro (Source: Proteonomics, February 2006, pages 1351–1361).