So far this holiday season, I’ve been on the lookout for awesome beauty buys in the skin care arena.  And by far, the champion has been the Kinerase Winter Skin Brightening Collection ($135.00, Sephora.com).  The collection, available exclusively at Sephora, contains four full-size products: Gentle Daily Cleanser, Under Eye Rescue, Brightening Facial Serum, and Cream – a true $275.00 value!   I was so excited to find this, I picked myself up one for my birthday (November 19, in case you were wondering, haha).

Even better, you can get an additional 8% back on your Sephora purchase in the form of a rebate check if you sign up at eBates.com!

As for more about Kinerase…

Kinetin: Not quite a retinoid, but great for sensitive skin

Kinetin has often been touted as a “sensitive skin alternative to retinoids.” In a 2004 review by HA Epstein, a patient self-assessment of “good to excellent” improvement was noted in signs of photoaging (skin roughness, mottling, and fine wrinkling).  These assessments were more than doubled forKinerase in each category than when compared with a cream containing Renova, a prescription 0.02% tretinoin (retinoid) cream.

Unfortunately, no independent published studies of kinetin could be found in comparison to more potent retinoid treatments like Retin-A (0.04 or 0.1% tretinoin) or over-the-counter retinol treatments. According to experts like PE Bermann in a 2007 review, “[Non-retinoid treatments] cannot produce the dramatic results obtained with [potent] tretinoin.” Therefore, based on current published research, 0.1% kinetin (as in Kinerase) may be more effective than 0.02% tretinoin (Renova), but should not be considered more effective than 0.04% or 0.1% tretinoin (Retin-A).

An effective antioxidant

Kinetin was been found in a 2000 study to be a strong inhibitor of oxidative and glycoxidative protein damage in cultured human fibroblasts (skin cells). In the study, kinetin proves to be a potent antioxidant by mimicking superoxide dismutase activity, activating superoxide dismutase and catalase, and by quenching reactive oxygen species (i.e., free radicals). Unfortunately, no published independent studies compare the antioxidant capacity of kinetin to potent antioxidants such as coffee berry, green tea, vitamin C or vitamin E. A 1999 study by Olsen et. al. found that a concentration of 100 µM provides a maximum of 50% protection against oxidative DNA damage in the calf thymus. Unfortunately, this is not too promising, considering that products like Neutrogena Anti-Oxidant Age Reverse Day Lotion ($15.99,Amazon.com) has been reported by Johnson and Johnson (the makers of the product) to neutralize 99% of free radicals in the skin. Of course, these studies are clearly not parallel (a calf thymus is not human skin, the Neutrogena study is by the company, etc.!), and so results cannot directly be compared. However, the implication that superior antioxidant protection is available for less money than Kinerase certainly is there. Further independent studies certainly must be done to determine the antioxidant capacity of kinetin relative to other ingredients.

Activates repair enzymes

Kinetin has been found to stimulate transcription in plant cells and increase the rate of cell cycle. In addition, kinetin can induce the synthesis of repair enzymes, which either remove modified bases from DNA and/or protect against oxidative stress (Cosmetic Dermatology). In fact, in a 1995 study by Sharma et. al., kinetin-fed fruit flies had a 55%–60% increase in the activity of the antioxidant enzyme catalase, which breaks down hydrogen peroxide (a free-radical creator) in the cells. According to the review by HA Epstein, collective kinetin studies on human skin cells and fruit flies have shown that it can delay onset of several cellular and biochemical characteristics associated with cellular aging in long-term cultures of human skin fibroblasts via antioxidant and DNA repair enzyme activity.

Extends the life of fruit flies

In a 1995 study by Sharma et. al., kinetin-fed fruit flies demonstrated a 65% increase in prolonged lifespan and a 25% slowing of aging. It is unknown at what dose humans can safely ingest kinetin (found in some plants and herring), or if the fruit-fly data even apply to humans at all.

Overall Opinions

Kinerase is one of my personal favorite lines, and I looooove this kit.  While some readers may find the line to usually be a bit pricey, the fact that each product is less than $40 in this kit makes this holiday season THE time to try Kinerase!

In summary, kinetin has proven to be able to repair DNA and serve as an antioxidant, with overall resultsmost likely somewhere between Renova (0.02% tretinoin), like Retin-A (0.04% or 0.1% tretinoin). With the limited independent research studies conducted on topically applied kinetin, it is hard at this time to know its true efficacy.  Despite this, I love the kit, and I’m a devoted fan!