Benzoyl peroxide, naturally antibacterial and antiseptic, treats acne by reducing P. acnes bacteria on the skin’s surface. It also breaks up dead skin cells and dries any excess oil. Because benzoyl peroxide can irritate the skin and cause flakiness, be sure to apply moisturizer daily (regardless of your skin type). Also, start with a lower strength product and work your way up if you don’t experience any adverse reactions. Benzoyl peroxide ranges in strength from 2.5 percent to 10 percent (or more, for a prescription-strength formula).

• Best for: People who have very oily, resistant skin (such as teens) and those who find that many acne treatments aren’t strong enough.
• Skip it if: You’ve got sensitive skin that’s excessively dry or easily irritated. If you have combination skin, use benzoyl peroxide on the oilier T-zone area and apply a different product to the cheeks. Some find that benzoyl peroxide is less drying and irritating when used as a spot treatment (versus all over the face). So, experiment to find the best way to take advantage of this powerful ingredient.
• Product picks: B. Kamins Medicated Acne Gel 5%, Jan Marini Benzoyl Peroxide 2.5% Wash and PCA SKIN pHaze 33 Acne Cream.

Salicylic acid, a beta hydroxy acid, helps to normalize the shedding of dead skin cells, which is often inconsistent with acne-prone or oily skin. If these dead skin cells aren’t routinely exfoliated away, they can mix with sebum (the skin’s natural moisturizer) and block pores, causing acne.

• Best for: Someone with dry or sensitive skin who needs a gentler acne treatment or has experienced excessive drying when using benzoyl peroxide or other acne-fighting ingredients.
• Skip it if: You have an allergy to aspirin — the chemical compound in salicylic acid is similar to aspirin. When starting a new product, always watch for signs of dryness and irritation.
• Product picks: SkinCeuticals Clarifying Cleanser, SensiClear Blemish Free Acne Treatment Lotion and Ole Henriksen Blemish Attack Daily Defense Gel.

Glycolic acid is an alpha hydroxy acid that helps to refine the skin’s texture by dissolving dead skin cells to reveal newer, healthier skin. Like salicylic acid, it prevents breakouts by shedding dead skin before it mixes with oil and dirt and has a chance to clog the pores. Glycolic acid also improves the effectiveness of other skincare products — making it particularly effective in fighting acne. Plus, it helps to bring moisture to the skin’s surface, leaving your complexion looking radiant.

• Best for: Anyone looking to combat adult acne, because glycolic acid targets both blemishes and fine lines and wrinkles.
• Skip it if: You’re pregnant, a teen or have sensitive skin. Also, avoid glycolic acid if you’ve experienced a negative reaction while using any type of alpha hydroxy acid. This is a powerful ingredient that can be irritating for many individuals.
• Product picks: Peter Thomas Roth Glycolic Acid 3% Facial Wash, pH Advantage Anti Aging Glycolic Exfoliating Moisturizer 1 and DDF Glycolic 10% Toning Complex.

Is it working?

• Have patience. As with all new products and routines, seeing results can take weeks. At a minimum, give any new product at least one month before you decide whether it’s working.
• Pay attention. After you begin using a new product, monitor your skin’s reaction carefully. Does it feel too dry or tight after cleansing? Is there noticeable flaking of the skin? Any redness or irritation? Give your skin some time to adjust to the new product, but if the problem doesn’t seem to be improving, either cut back your use or discontinue.
• Be consistent. Frequently changing your skincare products can do more harm than good. So, once you find a routine and rhythm that suits your skin, stick with it — even if you see positive results immediately. Blemishes tend to pop up routinely and in the same place. As such, to beat blemishes and prevent their return, it’s vital to maintain a consistent, long-term regimen. Merely using an acne product for a week or two is unlikely to produce a long-lasting, clear complexion.

Learn everything you need to know about acne-fighting skincare in our Complete Acne Handbook.