Does benzoyl peroxide cause purging?

Why can acne look worse after starting?

Benzoyl peroxide reduces acne bacteria and mildly helps clear clogged pores. Its side effects include dryness, peeling, burning and stinging. Irritation is therefore one explanation for trouble after starting treatment, rather than proof that the treatment is working. Benzoyl peroxide treats acne, but it does not deserve a performance bonus for every new spot.34

Acne itself involves blocked or inflamed oil glands and bacteria. Skin irritation can also trigger pimples. A new spot alone cannot tell you which process is responsible. Look beyond the spot count: dryness and peeling are common benzoyl peroxide side effects, while deep, painful lumps need medical attention rather than a new name.56

How should you start benzoyl peroxide?

1. 1Choose a low concentration. A 2.5% product is a starting option to reduce irritation; lower concentrations and wash formulations are generally less irritating.
2. 2For a gel you leave on, wash your hands, gently clean and dry your skin, then apply a thin layer to the affected area. Wash your hands afterwards.
3. 3For a gel wash, wet the area, wash with a small amount for 1 to 2 minutes, rinse and pat dry. Follow your product's directions.
4. 4Use the labelled frequency, usually once or twice daily. If 2.5% irritates your skin, try every other day.

What should the rest of your routine look like?

Wash with a gentle cleanser twice daily, using your fingertips rather than scrubbing. Pat dry with a clean towel. Choose skincare and makeup labelled 'noncomedogenic', meaning formulated not to clog pores. The useful label tells you about clogged pores, not how ambitious the marketing department felt. Remove makeup at the end of the day, and avoid picking or squeezing spots because that can cause scars.16

If your product also contains a retinoid, such as adapalene, both ingredients can contribute to irritation. Retinoids are vitamin A related medicines that help prevent clogged pores. Benzoyl peroxide and retinoids can be effective together, but do not add other acne medicines without checking with a pharmacist or doctor. Tretinoin can degrade in the presence of benzoyl peroxide, so check how to arrange that prescription routine.1235

How long should you wait for improvement?

Benzoyl peroxide usually starts working within 4 weeks. If acne has not improved after 12 weeks, get advice; worsening deserves advice sooner. Mild side effects often improve after a few days or with less frequent use. Individual pimples usually last 3 to 7 days, while deeper pimples can last weeks, so an existing spot's lifespan is not the same as the treatment's response time.25

When should you stop or get help?

Get medical help for deep, painful or scarring acne, signs of infection, or acne affecting your mental health. Seek emergency help for throat or tongue swelling or difficulty breathing. Do not apply benzoyl peroxide to broken or infected skin. Use sunscreen and keep the medicine away from your eyes and mouth.26

Benzoyl peroxide can usually be used during pregnancy, but check with your doctor. Check before using it while breastfeeding, and avoid applying it to your breasts.2