Understanding Alpha

Two topical ways to exfoliate the skin is with AHA's and BHA. Exfoliation is important in all skincare - it will help with everything from Aging to Acne to Dry skin and so on. Chemical exfoliation is better than cosmetic scrubs because they can work at a deeper level, but have a natural stop point - so you can't damage skin (if you are using the right percentages) like you can with a scrub. In the case of BHA, it can even work inside the pore. Removing the dead layer of skin can improve skin texture and color, unclog pores, and allow moisturizers to be better absorbed by the skin. Both AHAs and BHA allso help to improve the appearance of sun-damaged skin, dry skin, and thickened skin caused by a variety of factors such as sun and smoking. There are five types of AHA's and only one BHA.
AHA's workat a concentration of 5-8% and a pH of 3-4!!!Generally, if the AHA is listed second or third then it has the correct percentage (and many will tell you the percent on the label). AHA's also have water-binding properties, so even atan incorrect pH and a lower percentage, they will moisturize the skin. There are many products out there that have a higher concentration. You can go up to about 12% without damage, but it willnot help any more than 8%. More than12% does damage the skin.The "positive" resultspeople perceive whenusing high concentrations is from the swelling and edema they cause. That will diminishwrinkles and make the skin smooth, but the long-term condition of the skin is hurt dramatically because of the constant irritation.A higher concentration can be used in a doctors office (it is not constant that way and the doctor should be knowledgable as to how often it can be done and how your skin reacts to it)!
Here is a review of each AHA and the one BHA.
Salicylic Acid - This is the only BHA. The difference between an AHA and BHA is that the BHA is lipid (fat) soluble. AHA's are water soluble. This means that BHA can penetrate the oil in the pores - AHA's cannot. So, BHA is best for blackheads and blemishes where AHA's are good for sun damaged, thickened, and dry skin. BHA worksat a concentration of 1-2% and a pH of 3-4!!! The percentage of Salicylic Acid should always be on the label - if it is not then find out what it is before you purchase it. Higher than 2% will damage your skin and lower than 1% will not do anything. pH is a little harder to find, you can always ask (the easy way) or get some litmus paper (you can find it in a science or pool store) and check it yourself.
Glycolic Acid - There is a lot of research that shows that the use of this AHA can also improve skin discoloration, increase collagen production, and reinforce the protective function of skin. It is absorbed the quickest in the group (so works fastest and with greatest result)- but, itis the most irritating. People with extremely sensitive skin will probably not want to use Glycolic Acid.
Lactic Acid - Has a greater moisturizing effect. It isa very large molecule so it takes longer to absorb. Great for dry and/or sensitive skin.
Malic Acid - Smooth/slippery consistency that will leave a protective coat on the skin.
Citric Acid - Usually added to lower the pH so the other ones can work better! Not too many products use them as the sole AHA.
Tartaric Acid - Strongest acid of the group, not used often.