Lactic acid is an incredibly efficient ingredient for subtle skin exfoliating. It loosens dead skin cells, dissolves impurities and sebum, and encourages cell turnover and renewal. There are many products that utilize lactic acids, from rinse-off cleansers (I'm fond of Dermalogica) to hardcore peels containing a high percentage of the acid. Masks are somewhere in the middle-- they sit on the skin for a while and do their thing, but the acid is usually tempered with other ingredients so it's not too harsh on sensitive skin.
Chella Resurfacing Mask Enzyme and Lactic Treatment is one such product. Formulated with 4% lactic acid, sugar cane and fruit enzymes, the mask is an efficient chemical exfoliant (meaning no manual scrubbing or abrasion needed). It's not very radical (some professional peels have much higher percentages of the active acid), but it does the work. My skin isn't particularly sensitive and is quite used to various chemical peels, yet I could feel a light stinging the first time I used this Chella mask.
Chella directs us to leave the mask on for 15 minutes and only use it once a week. I'd recommend not going over 10 minutes the first time you apply it, and increase exposure on subsequent treatments. I've been using the mask for several weeks now, and admit to doing it once every five days or so, but as I said: I'm a veteran of home peels. I find that the Chella mask does a world of good in terms of smoothing and purifying the skin, and as usual, it increases the effectiveness of nourishing serums and creams.
Bottom Line: a good one.
Chella Skin Care- Resurfacing Mask Enzyme and Lactic Treatment ($60, 2.5oz) is available from Dermstore and chella.com. I have no idea who sent me the product for this review, but I do know it was some sort of a PR freebie.