What it is: You may have heard of tretinoin in reference to "Retin-A" wrinkle treatments. Tretinoin is retinoic acid and vitamin A acid combined, and comes in various strengths in creams, gels, and liquids for topical use on the skin. It is used to treat acne and also to treat sun damaged skin or wrinkles and is usually applied once per day.1Learn more from the U.S. National Library of Medicine.
Benzoyl peroxide attacks the P. acnes bacteria. However, one of its main side effects is dryness: If you’re going to use anything with benzoyl peroxide, make sure to moisturize afterwards. Sulfur and azelaic acid are less common and less severe alternatives to benzoyl peroxide. Dr. Peter Lio, assistant professor of clinical dermatology at Northwestern University, says sulfur-based treatments are “a good fit for patients who can’t tolerate the side effects of benzoyl peroxide.”
How to Handle It: Your best bet is benzoyl peroxide. "Benzoyl peroxide can kill acne-causing bacteria and reduce inflammation," says Zeichner. Try a cream like the La Roche-Posay Effaclar Duo Dual-Action Acne Treatment ($37), which also exfoliates with lipo-hydroxy acid. Be aware that it can seriously dry out skin so moisturize well after you use it.
Salicylic acid is a topically applied beta-hydroxy acid that stops bacteria from reproducing and has keratolytic properties. It opens obstructed skin pores and promotes shedding of epithelial skin cells. Salicylic acid is known to be less effective than retinoid therapy. Dry skin is the most commonly seen side effect with topical application, though darkening of the skin has been observed in individuals with darker skin types.
For those with acne-prone skin, it can be tough finding a sunscreen that doesn’t clog pores and meshes well with your skincare regimen. Oily sunscreens often lead to breakouts. In addition to the wash, toner, moisturizer and treatments, the Clear Start kit includes an acne-safe (read: oil-free) sunscreen in its lineup — perfect for those wanting the best of both worlds in avoiding all types of red faces.
If you have oily, tight skin and tend to get age spots or sun spots, try an exfoliant made with glycolic acid right after you cleanse your skin, no more than 4 or 5 times a week. Aveeno Positively Radiant Cleansing Pads provides just a “dab” of exfoliant that will help lighten the spots without irritating your skin (which over the long run would create new brown spots).
Salicylic acid and azelaic acid. Azelaic acid is a naturally occurring acid found in whole-grain cereals and animal products. It has antibacterial properties. A 20 percent azelaic acid cream seems to be as effective as many conventional acne treatments when used twice a day for at least four weeks. It's even more effective when used in combination with erythromycin. Prescription azelaic acid (Azelex, Finacea) is an option during pregnancy and while breast-feeding. Side effects include skin discoloration and minor skin irritation.
Retinoids – Recommended for people with moderate to severe acne, retinoids can unclog your pores, allowing for your other medicated acne treatments to penetrate deeper. They can reduce your potential for outbreaks and the formation of acne scarring2. You can also use a retinoid cream directly as a treatment after your face cleanse, or even take it in the form of a retinoid pill to treat oil/sebum production and to treat inflammation and acne-causing bacteria.
Glycolic acid is another chemical exfoliant that dissolves the structural lipids that hold dead skin cells and bind them to the surface. But aside from this, studies have also shown that glycolic acid effectively encourages and stimulates the production of collagen and elastin, restoring damaged skin faster and reducing signs of environmental damage with continuous use.
Azelaic acid has been shown to be effective for mild to moderate acne when applied topically at a 20% concentration. Treatment twice daily for six months is necessary, and is as effective as topical benzoyl peroxide 5%, isotretinoin 0.05%, and erythromycin 2%. Azelaic acid is thought to be an effective acne treatment due to its ability to reduce skin cell accumulation in the follicle, and its antibacterial and anti-inflammatory properties. It has a slight skin-lightening effect due to its ability to inhibit melanin synthesis, and is therefore useful in treating of individuals with acne who are also affected by postinflammatory hyperpigmentation. Azelaic acid may cause skin irritation but is otherwise very safe. It is less effective and more expensive than retinoids.
Benzoyl peroxide is one of the most popular acne medications available, and it works especially well for pimples because it kills the bacteria that causes them. It works by bringing oxygen under the skin, killing the particular type of bacteria associated with acne, known as p. acnes. P. acnes are anaerobic, meaning they can’t live where there is oxygen, so benzoyl peroxide is a great way to kill bacteria under the skin instantaneously1. This medication can often eradicate acne if used in the right dosage and in the right way.
Acne treatment that you apply to the skin: Most acne treatments are applied to the skin. Your dermatologist may call this topical treatment. There are many topical acne treatments. Some topicals help kill the bacteria. Others work on reducing the oil. The topical medicine may contain a retinoid, prescription-strength benzoyl peroxide, antibiotic, or even salicylic acid. Your dermatologist will determine what you need.