The Difference Between Glycolic and Salicylic Acid

Episode #69 / Aug 18, 2009
When it comes to facial exfoliation, there are two acids which do a majority of the work: glycolic and salicylic. Dr. Schultz will explain the difference between the two and what they're both used for.
Andrea on October 8, 2009 at 12:25pm

Hello Dr Schultz,

What about Lactic Acid? I heard it´s the best type of chemical peel for hyerpigmentation, also it´s said to be more gentle than other peels.

Neal Schultz, M.D. on October 27, 2009 at 11:45pm

@Andrea: You are correct that Lactic acid is the most gentle AHA (alpha hydroxy acid) and is the first AHA used clinically for patients (1965) in a product called Lachydrin Lotion, that is still available and promoted to help dry skin in older patients. Because of its very gentle strength, I find it not to be very effective by itself for hyperpigmentation but do use it combined with other exfoliants and bleaches.

Jussara on November 3, 2009 at 7:08pm

Hi Dr Schultz,
What about Azelaic acid? I've heard that it's an antioxidant. Is that true? If so, can I apply it first and after apply the vitamin C?
I'm a big fan of DermTV and your valuable tips. Sorry about my bad Enghlish, that is not my first language.
Thank you!

Neal Schultz, M.D. on November 20, 2009 at 9:10pm

@Jussara: Thank you for your support! Azelaic Acid is an antibacterial and an anti-inflammatory agent that has properties similar to an antioxidant. It is safe to apply in conjunction with your Vitamin C cream but for best results use both at night, not during the day. See In What Order to Apply Your Skin Care Products for more information on the order of application.

Jussara on December 5, 2009 at 4:34pm

Thank you very much, Dr Schultz! :-)

zehra on March 26, 2010 at 11:43pm

which exfoliant do you reccommend for combination skin which is sometimes becomes very dry in winter even with some flaky patches,but in summer its more like normal to it true tat salicylic acid dissolve sebum too.My skin is bit sensitive too.

Neal Schultz, M.D. on June 1, 2010 at 1:36am

@zehra: The seasonal issues you're describing need to be addressed by changing the vehicle (e.g., lotion, gel, etc.) your exfoliant is in and not by changing the actual exfolianting product. For more information on this, see Why Change Your Skincare Products Periodically. In addition, other measures may be necessary (moisturizer) to address the seasonal imbalances you described.

Regarding salicylic acid and sebum, salicylic acid does not dissolve sebum, but does dissolve keratin.

Niki on June 11, 2010 at 5:05am

Dr. Shultz,
A couple of years back, a dermatologist used an acid on my face for melasma / dark patches that I acquired after having children and worsened with sun exposure. I THINK it was called "Jezebel" - it was a high potency acid, and after being applied for 2 minutes, it took about 7 days for the peeling to stop. Because some peeling caused bleeding, the doctor only left the acid on for 45 seconds the second time. Some of the dark spots came off, some did not, and some returned. Can you make a suggestion as to what kind of in-home peel I should use on my face? I just turned 50.

Thank you for your assistance!

Neal Schultz, M.D. on June 14, 2010 at 11:31pm

@Niki: Peels for melasma are very tricky and can easily make the condition worse. I do not advise any "at-home peel" for this problem. If a condition such as the one you described doesn't respond to the usual trio of sunscreens, exfoliants and bleach products at home (see How to Remove Brown Spots), then see a dermatologist for stronger treatment...please don't try the at-home peel's in my opinion much too dangerous!