今天在paula choice的官网上看到有不错的关于AHA 和BHA的介绍，BHA其实就是水杨酸，这个对于黑头和痘痘都很有帮助的。感觉这个牌子在这一个方面做得挺专业的。虽然他家在美国没有local store, 但是这个网站做得很好，很少有网站有那么详尽的产品信息，赞一个。另外要赞的是它家有小包装的sample出售，也就是几毛钱美金的样子，像用于鼻子等局部的exfoliants, 其实真的不需要买full size, 买几个sample都已经可以用很久了，反正每周也就用一两次。
http://www.cosmeticscop.com/faq.asp#aha
Exfoliants, AHA vs. BHA
What's the difference between BHA and AHA?
BHA is oil-soluble and can penetrate into the pore exfoliating accumulated skin cells that clog pores and can also exfoliate on the surface of skin as well. It is best for skin types prone to blackheads and blemishes. AHAs are water-soluble and exfoliate primarily on the surface of the skin. They are generally best for sun-damaged skin that is not prone to blemishes. AHA's also have moisturizing properties.
What are the pH levels for Paula's Choice AHA and the BHA products?
AHAs (Alpha Hydroxy Acids) and BHA (Beta Hydroxy Acid) both work best at a pH of 3 to 4. Our 8% Alpha Hydroxy Acid Solution has a pH of 3.5, and our Skin Revealing Body Lotion with 10% AHA has a pH of 3. Our 1% Beta Hydroxy Acid Lotion and 2% Beta Hydroxy Acid Liquid both have a pH of 3.2. Our 1% Beta Hydroxy Acid Gel, 2% Beta Hydroxy Acid Gel, and 2% Beta Hydroxy Acid Lotion have a pH of 3.4. while our Weightless Body Treatment with 2% Beta Hydroxy Acid has a pH of 3.3.
Your AHA products (glycolic acid) have a higher percentage than your BHA products (salicylic acid). Does this mean they are stronger exfoliants?
The difference in concentrations between AHAs and BHA is not a qualitative one. AHAs are not more effective or better than BHA because of the increased concentration needed for one versus the other. Rather, AHAs are most effective at 5% to 10% and BHA at 1% to 2%. There are many examples in skin care where percentage of an ingredient doesn't demonstrate superiority and this is the case here. (Sources: Women's Health In Primary Care, July 2003, pages 333-339; Journal of Dermatological Treatment, April 2004, pages 88-93; Dermatology, January 1999; pages 50-53; Journal of the American Academy of Dermatology, April 1997, pages 589-593).
What's the difference between the various 1% and 2% BHA products?
The 1% Beta Hydroxy Acid Lotion is in a light lotion base that dries to a matte finish and the 2% Beta Hydroxy Acid Lotion is in a creamier base that still feels light on the skin yet also moisturizes. These are best for normal to dry or combination skin types with mild to moderate breakouts and blackheads.
The 1% Beta Hydroxy Acid Gel and 2% Beta Hydroxy Acid Gel are water-based silky finish formulas that are best for those with normal to oily or combination skin prone to blemishes and blackheads. They absorb quickly and are barely felt on the skin.
The 2% Beta Hydroxy Acid Liquid is a clear liquid that contains a slip agent to enhance the penetration of the salicylic acid, while keeping the skin soft and smooth. It is best for someone with normal to very oily skin with stubborn breakouts or blackheads.
What is the difference between the 1% Beta Hydroxy Acid Gel and the 1% Beta Hydroxy Acid Lotion?
The main difference is texture. The 1% Beta Hydroxy Acid Lotion has a lightly moisturizing lotion base while our 1% Beta Hydroxy Acid Gel features a water-light gel base that provides slightly less hydration and is barely felt on the skin. Both products contain the same concentration of salicylic acid and have a pH level low enough to facilitate exfoliation. Both products are also appropriate for all skin types, though those with oily to very oily skin may naturally prefer the 1% BHA Gel's texture.
I currently use the 1% Beta Hydroxy Acid Lotion. Should I switch to the 1% Beta Hydroxy Acid Gel? Can I use both?
It is entirely a matter of personal preference. If the texture and finish of the 1% Beta Hydroxy Acid Lotion appeal to you and has been working for your skin, then there is no reason to switch. However, if you want an even lighter texture or your skin has become oilier (such as can occur seasonally) then the 1% Beta Hydroxy Acid Gel may be an option for you. It is perfectly fine to use both of our 1% BHA products, though use only one at a time (i.e. apply the 1% BHA lotion in the morning under makeup and the 1% BHA Gel in the evening).
Is Paula's Choice 1% Beta Hydroxy Acid Gel stronger than the 1% Beta Hydroxy Acid Lotion?
From a percentage of active ingredient standpoint, no. However, because the 1% Beta Hydroxy Acid Gel is some what better able to penetrate into the pore which can produce faster (but not necessarily better) results. The drawback with this enhanced penetration is that it may increase the likelihood of skin flaking or peeling for some people. The 1% BHA Lotion's base allows for slower, more controlled penetration of salicylic acid.
How does Paula's Choice 2% Beta Hydroxy Acid Gel compare to the 2% Beta Hydroxy Acid Liquid?
The main difference is texture. The 2% Beta Hydroxy Acid Liquid has a toner-like consistency, and its base allows faster penetration of salicylic acid into the pore lining while providing ultra-light hydration.
The 2% Beta Hydroxy Acid Gel has a water-light gel base that lightly hydrates without feeling thick or greasy. Both products contain the same concentration of salicylic acid and have a pH level low enough for effective exfoliation. Both products are also appropriate for all skin types, though those with oily to very oily skin may naturally prefer the 2% BHA Liquid's texture.
I currently use Paula's Choice 2% Beta Hydroxy Acid Lotion. Should I switch to the 2% Beta Hydroxy Acid Gel? Is it all right to use both?
It is entirely a matter of personal preference. If you like the texture and finish of the 2% Beta Hydroxy Acid Lotion and it worked for your skin, then stick with it. However, if you want a lighter texture or your skin has become oilier (such as can occur seasonally—think summer vs. winter skin) then you may consider the 2% Beta Hydroxy Acid Gel. It is completely acceptable to use more than one of our 2% BHA products, though use only one at a time. A typical regimen would be to apply the 2% BHA Gel in the morning under makeup and the 2% BHA Lotion in the evening.
Is Paula's Choice 2% Beta Hydroxy Acid Gel stronger than the 2% Beta Hydroxy Acid Liquid?
No. Both products have the same concentration of salicylic acid formulated in the correct pH range for exfoliation to occur. Both products also have a glycol base courtesy of the ingredient methylpropanediol. This ingredient enhances the penetration of salicylic acid while also having water-binding properties for skin. Which product to choose comes down to whether you want a liquid (toner-like) or gel texture.
I have tried Paula's Choice 2% Beta Hydroxy Acid Lotion and 2% Beta Hydroxy Acid Liquid and did not care for the texture of either. Will the 2% Beta Hydroxy Acid Gel work for me?
Quite possibly, yes. If you're looking for a BHA exfoliant with a texture that's lighter than our 2% BHA Lotion but not as liquidy as our 2% BHA Liquid, the 2% BHA Gel should be an ideal "happy medium" for your skin.
Which BHA should I use?
Use the one that will produce the best results for your skin type. We recommend starting with a 1% BHA concentration before moving to a 2%, unless you have very oily skin and stubborn, persistent breakouts. For more information about exfoliants, read Paula's article Understanding Exfoliants.
I use one of your BHA products and have noticed some of my towels and/or pillowcases have become stained, almost as if they were bleached. Why does this happen?
When salicylic acid is formulated with a lower pH range (between 3-4), which is essential for it to work effectively as an exfoliant, there is a very small risk it may have a lightening effect on dyed natural fabrics such as cotton or linen in necklines of shirts or pillowcases. You can easily eliminate this potential problem by waiting for the BHA product to absorb and dry completely before coming into contact with such dyed fabrics.
Can I use both an AHA and a BHA?
You can use both, and some of our customers do and have great results using both, but generally using one or the other is far more typical. We do not recommend using both on the same parts of the face at the same time.
How soon can I expect to see results?
That truly depends on your skin type and how often you use the product. Results can appear as soon as 1 day after use but may take up to 1 week.
I have dry, sun damaged skin AND breakouts in my t-zone—which should I use, an AHA or BHA product?
AHA is better for exfoliating sun-damaged surface skin and BHA is better at getting into the pores and exfoliating the accumulated skin cells that clog pores as well as exfoliating the surface of skin. A BHA product would probably work best but you can also experiment to see which one works best for your skin type.
How often should exfoliants be used?
This really depends on your skin and how it reacts to an AHA or BHA product. Once per day may be best, or you may find greater results from using it twice per day. Those with sensitive skin may do best with applying it once every other day. It does not matter if these are used morning or evening—or both, that decision is just personal preference.
After I apply an exfoliant, do I have to wait before applying moisturizers?
No, our moisturizers can be applied to dry areas immediately afterwards.
Why doesn't Paula make a face scrub?
Topical scrubs are simple ways to mechanically exfoliate skin, but these can be abrasive and harsh on the skin, and they also exfoliate unevenly. A good deal of research has established that chemical exfoliants such as salicylic acid (BHA) and alpha hydroxy acids (AHAs) are not only effective for gently removing excess surface cells, but they also increase collagen production, promote cell turnover, reduce the appearance of skin discolorations, and improve the overall health of the skin. These additional benefits make an AHA or BHA product preferred to exfoliating skin with a topical scrub.
What do I do when my skin "gets used to" my AHA/BHA?
Your skin doesn't "get used to" an AHA or BHA, but AHAs and BHA do have a drop-off point, because there is only so much surface exfoliation or exfoliation in the pore that can take place. The longer you use these products, the less "dramatic" the results will be. However, they will always be beneficial for maintaining smooth, even-textured skin and encouraging ongoing healthy cell turnover.
What will happen if I stop using exfoliants?
Your skin may retain some of the smoothness from the AHA/BHA treatment as they can generate collagen production, but as the sun-damaged skin cells or skin cells that grow abnormally collect once again, your skin will slowly revert to the way it was before you started using the products.
Can AHA or BHA be used around the eyes?
Do not apply the AHA or BHA products too close to the eyes or to the eyelid or underbrow areas. You may try a small amount in the general under-eye area (going no closer to the eye than the orbital bone) to see how your skin reacts. If your skin seems fine, then gently pat the AHA or BHA closer to the eye, making sure not to get it too close or in the eye.
Should I use an AHA on my face and neck?
You can and should use this on your neck or chest if that area is sun damaged.
Can BHA be used on teens and/or pre-teens?
Yes, this is fine and often beneficial for teens, especially those with acne or blackheads.
Can I use AHA and/or BHA products on areas other than my face?
Paula's Choice AHA and BHA products can be used anywhere on the body. They work very well to exfoliate dry elbows, knees, feet, and arms. However, if you prefer a product formulated specifically for the body, try our Skin Revealing Body Lotion with 10% Alpha Hydroxy Acid or Weightless Body Treatment with 2% Beta Hydroxy Acid.
Can the AHA and/or BHA products be used during pregnancy or while lactating?
Although topical exfoliants should not pose a problem for pregnant woman, we do recommend asking your doctor before using or continuing to use an AHA or BHA product while pregnant or if you are lactating.
Do I have to use sunscreen if I am using an AHA or BHA product?
For the long-term health and appearance of your skin, you certainly should get in to the habit of applying sunscreen every day, rain or shine, especially when you are using an AHA or BHA product. Since these topical exfoliants work to remove layers of sun-damaged skin, it is vitally important that the fresh, new skin is well-protected from UV light. Ironically, the sun-damaged layer of skin (which the AHA or BHA products nicely remove) serves as your skin's first line of defense against sun exposure. Think of it as a callus that offers minimal protection while keeping your skin from looking and feeling its best.
How does using an AHA or BHA affect the results I get from using Almost the Real Thing Self-Tanning Gel?
There are pros and cons to combining any exfoliant (AHA or BHA exfoliant or topical scrub) with a self-tanner. Almost all self-tanners contain dihydroxyacetone (a derivative of sugar that turns skin cells a shade of brown), which affects only the uppermost layers of skin. Exfoliants affect these same layers and, as a result, the exfoliant sloughs off the skin cells affected by the self-tanner, thus reducing how long your "tan" lasts. That’s the negative. The positive is that when the skin is smoother (the benefit of using a well-formulated exfoliant) you get much more even-toned results from the self-tanner. Unless you're willing to not use an AHA or BHA product or a topical scrub when trying to obtain and maintain a self-tan, the only solution is to compromise. That may involve using the BHA or AHA lotion less often (such as two or three times per week rather than daily) or applying Almost the Real Thing Self-Tanning Gel more often to maintain the level of color you like.
There is no question that smooth, exfoliated skin produces a more even "tan" from self-tanning products, but the irony is that these exfoliants hasten the departure of the tan, necessitating adjustments in your routine. With some experimentation, you should be able to use both products successfully. One last tip: even if other lotions are part of your regular routine, when self-tanning, the Almost the Real Thing Self Tanning Gel works best when applied to smooth, clean skin.
