How Exfoliation Works
Exfoliating Makes Skin Look Younger!
The Best Way to Exfoliate For Your Skin Type
The Problem with Scrubs
How Do You Use AHAs or BHA?
Can You Exfoliate Too Often?

Perhaps no other part of a daily skin care routine can have the most immediate impact as gently exfoliating skin. Though there are a few different ways to exfoliate skin by far the most effective and well researched are alpha hydroxy acids (abbreviated to AHAs, with the most common ones being glycolic or lactic acid) and beta hydroxy acid (abbreviated to BHA, active ingredient: salicylic acid). The benefits of using a well-formulated AHA or BHA can be apparent almost immediately, or at the very least, within a few days of use. Best of all, skin will continue to improve over time with ongoing use.

How Exfoliation Works
We shed billions of skin cells every day. When that doesn’t occur in a normal manner it isn’t pretty. When we are young, skin cells are regenerated and turn over very quickly, about once a week for children. As we age, the rate of skin cell renewal changes to every three weeks through our teens and 20s, and then slows as we get older due to sun damage and other factors such as menopause. Sun damage is the worst offender over time, causing the outer layer of skin to thicken and making it look more wrinkled. For those with blemish-prone skin research shows that the outer layer of skin is thicker and the pore lining is thicker as well. Exfoliation works to trigger skin cells to shed as they did when we were young, and that’s good news for almost everyone!

Those struggling with blemishes need to know that exfoliation of facial skin can also unclog pores by keeping dead skin cells from blocking the pore opening so sebum (oil) can flow more normally. This helps reduce blemishes and blackheads and it also allows antibacterial agents penetrate to where the bacteria causing acne is hiding (and proliferating).

Exfoliating Makes Skin Look Younge
How is that possible? Well, the best analogy is to compare the built-up skin cells on the surface of your face to the heels of your feet. Before you get a pedicure the built-up dead layer of skin on your heels looks dry, rough, discolored, scaly, and lines are pronounced. Once that layer is removed, and it can be removed fairly aggressively without damaging anything, your heels look much better. Moreover, once you apply moisturizer, which can now absorb better because it hasn't been blocked by built-up skin cells, viola-you have "younger"-looking feet. I'm not suggesting we should be that aggressive from the neck up or on most parts of your body (and the cause for calluses is different then what causes skin cells to build up on the face), but the same benefit of exfoliating heels holds true for the face, you just have to be gentler than you are with your heels.

What glycolic, lactic, and salicylic acids all do is imperceptibly "unglue" the outer layer of dead skin cells, allowing healthier cells to appear on the surface.

The Best Way to Exfoliate For Your Skin Type 
The primary difference between AHAs and BHA is that AHAs are water-soluble, while BHA is lipid-(oil) soluble. This unique property of BHA allows it to penetrate the oil in the pores and exfoliate accumulated skin cells inside the oil gland that can clog pores. BHA is best used where blackheads and blemishes are the issue, and AHAs are best for sun-damaged, thickened, dry skin where breakouts are not a problem.

As a rule, AHAs are best for normal to dry, sun-damaged skin because they only exfoliate on the very surface of skin rather than inside the pore. My 8% Alpha Hydroxy Acid Gel is a great option to consider. BHA also exfoliates on the surface of skin but has extra properties that make it better for normal to oily or combination skin and especially for blemish-prone skin. Salicylic acid can exfoliate inside the pore and it has anti-inflammatory and mild antibacterial benefits as well.

Though BHA can work great for dry skin types as well, it takes experimenting to find out which one works best for you.

First-time users of a BHA product can begin with a 1% concentration of salicylic acid; those with oily to very oily skin and stubborn blackheads or blemishes should begin with a 2% concentration. If you decide to try Paula’s Choice BHA products, it’s important to know that each one is formulated with additional soothing agents. Once you know the concentration you want to try, the only thing left to decide is whether you want a gel, liquid (2% strength only), or lotion texture.

Generally if you have normal to oily skin with moderate breakouts my 1% BHA Gel is a great place to start. If you have very oily skin with moderate to severe breakouts the 2% BHA Liquid is a must to try. If you have normal to combination or slightly dry skin the BHA lotions are a wonderful option. Bottom line: which one to choose depends on personal preference more than any other factor plus experimenting to see what works best for you.

If you have acne, please refer to the CLEAR product range for more information.

The Problem with Scrubs
Scrubs can only deal with the very top, superficial layer of skin while the depth of unhealthy built up skin cells is below that surface layer. What is most problematic is that many scrubs (particularly those sold in “natural” lines) have a rough, coarse, uneven texture that can cause skin damage by tearing into the skin as it abrades away the surface, causing tiny tears that damage the skin’s barrier and cause more problems than they help solve.

For those with oily or blemish-prone skin the scrub particles are often suspended in waxy, thick base that can clog pores.

However, if you do want to use a manual scrub, you can simply use a gentle washcloth with your daily cleanser, which works just as well to exfoliate the surface of skin as any cosmetic scrub you can buy. As a bonus, washcloths are softer (thus gentler) and of course they don’t contain pore clogging ingredients.

How Do You Use AHAs or BHA?
You can apply an AHA or BHA product once or twice a day. Also, depending on your skin's sensitivity you can apply either of these around the eye area, making sure to keep them off the eyelid and away from the eye itself. Apply the AHA or BHA product after the face is cleansed and after your toner has dried (if you are using one). Once the AHA or BHA has been absorbed, you can apply any other product, such as additional moisturizer, serum, eye cream, sunscreen, and/or foundation.

Can You Exfoliate Too Often?
What about exfoliating too often? Does it hinder or harm cell production? Some of you have asked me about something known as the Hayflick Limit. The Hayflick response is a phenomenon that explains how many times skin cells will be reproduced. There seems to be a preset genetic determination of the number of times a skin cell will be regenerated. This turnover limit is only about what happens in the lower layer (basal) of skin where skin cells are produced. What happens on the surface in regard to exfoliation doesn't affect the number of times new skin cells are created.

Exfoliation is strictly about the dead surface layer of skin and that doesn't get anywhere near the lower layers where new skin cells are being reproduced. Removing top layers of skin doesn't cause new skin cells to be formed; the two functions are not related. So you don't need to worry about damaging new skin cells by using topical exfoliants. You do want to be careful to avoid exfoliants that are too strong or too abrasive because of the irritation and inflammation such products cause; this can harm skin more than help it, but that still doesn't affect cell regeneration or speed up the Hayflick Limit.

You may have heard or read that some cosmetic companies are proclaiming people should stop exfoliating skin. The reasoning is that by doing so you hold on to your epidermal (surface) cells longer, which creates a more youthful look. It is an absurd notion, any more then holding on to the dead built up calluses on your heels make sense. There is no reason to preserve our epidermal cells (the outer layers of skin), they are supposed to shed normally every day, millions of them! Routine exfoliation just helps them do it in a healthier, more normal manner instead of being hampered by sun damage, genetics, and menopause.

What they are confusing is the notion of wanting to preserve the basal layer of skin where skin cells are regenerated, but that is a genetic trigger and not something related in any way to how the surface of skin functions. If there is research showing that exfoliation changes cell regeneration I have never seen it, but I have seen lots of research showing that exfoliation is incredibly beneficial for skin. There is even research showing glycolic acid can reduce skin cancer occurrences, which is astounding.

Exfoliation is a key component for the health and appearance of your skin. It is necessary for most skin types and is as basic as a gentle cleanser, sunscreen, and the need for skin to get topically applied antioxidants and cell-communicating ingredients!

Sources for the Above Information: Free Radical Biology and Medicine, May 17, 2008; Archives of Dermatologic Research, April 2008, pages Supplemental S31-S38; and June 1997, pages 404–409; Journal of Cosmetic Dermatology, March 2007, pages 59-65; and September 2006, pages 246-253; Skin Pharmacology and Physiology, May 2006, pages 283-289; Food and Chemical Toxicology, November 1999, pages 1105-1111; Journal of the American Academy of Dermatology, September 1996, pages 388-391; Journal of Cosmetic Science, June 2008, pages 175–182; and March-April 2006, pages 203-204; European Journal of Dermatology, March-April 2002, pages 154-156; Molecular Carcinogenesis, July 2001, pages 152-160; Cancer Letters, December 2002, pages 125-135; Experimental Dermatology, January 2005, pages 34-40; and April 2003, Supplemental, pages 57–63; Dermatologic Surgery, May 2001, page 429; and May 1998, pages 573–577; International Journal Cosmetic Science, February 2005, pages 17-34; Global Cosmetic Industry, November 2000, pages 56-57; International Phytotherapy Research, November 2006, pages 921-934; Aesthetic and Plastic Surgery, May-June 2006, pages 356-362; Journal of Dermatology, January 2006, pages:16-22; Cosmetic Science, September-October 2002, pages 269-282; and British Journal of Dermatology, February 2001, pages 267-273.)