The form and dosage of salicylic acid in skin products determines how often you should apply it. Results may take several weeks to notice.

Salicylic acid is a beta hydroxy acid. It’s well-known for reducing acne by exfoliating the skin and keeping pores clear.

You can find salicylic acid in various over-the-counter (OTC) products. It’s also available in prescription-strength formulas.

Salicylic acid works best for mild acne (blackheads and whiteheads). It can also help prevent future breakouts.

Keep reading to learn how salicylic acid helps to clear acne, what form and dosage to use, and what potential side effects to be aware of.

When your hair follicles (pores) get plugged with dead skin cells and oil, blackheads (open plugged pores), whiteheads (closed plugged pores), or pimples (pustules) often appear.

Salicylic acid penetrates your skin and works to dissolve the dead skin cells clogging your pores. It can take several weeks of use for you to see its full effect. Check with your dermatologist if you aren’t seeing results after 6 weeks.

Your doctor or dermatologist will recommend a form and dosage specifically for your skin type and your skin’s current condition. They might also recommend that, for 2 or 3 days, you only apply a limited amount to a small area of affected skin to test your reaction before applying to the entire area.

According to the National Library of Medicine, adults should use a topical product to clear their acne, such as:

FormPercent of salicylic acidHow often to use
gel2–7%once per day
lotion2%1–3 times per day
ointment3%as needed
pads0.5–2%1–3 times per day
soap0.5–3%as needed
solution0.5–2%1–3 times per day

Products with higher concentrations of salicylic acid may be used as exfoliants

Salicylic acid is also used in higher concentrations as a peeling agent for the treatment of:

Although salicylic acid is considered safe overall, it may cause skin irritation when first starting. It may also remove too much oil, resulting in dryness and potential irritation.

Other potential side effects include:

  • skin tingling or stinging
  • itching
  • peeling skin
  • hives

Even though salicylic acid is available in OTC products you can pick up at your local grocery store, you should talk with your doctor before using it. Considerations to discuss include:

  • Allergies: Let your doctor know if you’ve experienced allergic reactions to salicylic acid or other topical medications before.
  • Use in children: Children may be at more risk of skin irritation. Speak with a doctor before your child starts using salicylic acid products.
  • Drug interactions: Certain medications do not interact well with salicylic acid. Let your doctor know what medications you’re currently taking.

You should also tell a doctor if you have any of the following medical conditions, as these may affect their decision to prescribe salicylic acid:

Salicylic acid toxicity

Salicylic acid toxicity is rare, but it can occur from topical application of salicylic acid. To reduce your risk, follow these recommendations:

  • do not apply salicylic acid products to large areas of your body
  • do not use it for long periods of time
  • do not use it under air-tight dressings, such as plastic wrap

Immediately stop using salicylic acid and see your doctor if you experience any of these symptoms or signs:

Using salicylic acid while pregnant or nursing

The American College of Obstetricians and Gynecologists (ACOG) notes that topical salicylic acid is generally safe to use while pregnant.

However, you should talk with your doctor if you’re considering using salicylic acid and are pregnant — or nursing — so you can get advice specific to your situation, especially regarding other medications you’re taking or medical conditions you may have.

A 2018 report on the use of salicylic acid during breastfeeding noted that while salicylic acid is unlikely to be absorbed into breast milk, you should not apply it to any areas of your body that might come into contact with an infant’s skin or mouth.

Although there’s no complete cure for acne, salicylic acid has been shown to help clear up breakouts for many people.

Talk with a doctor or dermatologist to see if salicylic acid is appropriate for your skin and your current health condition.