Acne develops when dead skin cells and oil block pores. Retinol increases skin cell production and helps prevent those blockages, but pimples can continue appearing while treatment gets started. Early worsening with retinol is sometimes called a purge, a name that gives an adjustment period the billing of a major event. Prescription retinoids such as tretinoin can also initially aggravate acne before reducing it.14

How long does a skin purge last?

There is no single countdown for every retinoid. With tretinoin, acne often worsens during the first 7 to 10 days; acne sores should begin improving in 2 to 3 weeks, although sometimes improvement takes more than 6 weeks. With retinol, pimples can continue through the first couple of months. Broader acne clearing takes longer: many treatments need 6 to 8 weeks before fewer breakouts appear, and topical retinoids can take 12 weeks or longer to show improvement. These are treatment timelines, not a reason to ignore worsening symptoms indefinitely.1256

Is it purging or irritation?

More pimples early in retinoid treatment can fit the expected initial worsening. Burning, stinging, peeling, redness and dry skin are also recognised side effects, so they should not automatically be treated as evidence of a purge. Irritation does not usually mean an allergy, but retinoids can cause irritant dermatitis, meaning irritated, inflamed skin, and occasionally allergic dermatitis. Purging is a description of early worsening, not a skincare loyalty test. If irritation is substantial, contact your prescriber rather than simply pushing through.256

How should you use treatment during a purge?

  1. 1Cleanse gently and let your skin dry as directed. Do not scrub or pick pimples; both can worsen acne.
  2. 2Apply treatment in the evening as directed. For cosmetic retinol, general guidance is a thin, pea sized layer every other night initially. Prescription tretinoin is usually used daily at bedtime, but follow your own prescription.
  3. 3Cover the acne prone area, not only individual spots. Keep retinoids away from eyes and lips, and do not apply tretinoin to sunburned skin or areas affected by eczema.
  4. 4Use moisturizer to help with dryness. For prescription treatment, ask your dermatologist before changing the amount, frequency or layering; applying moisturizer first is one option they can recommend.
  5. 5Protect exposed skin during the day with a sunscreen offering broad spectrum protection, SPF 30 or higher and water resistance. Use shade and protective clothing too.
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Do not switch products every few days: that can irritate skin and cause new breakouts. Applying extra treatment will not clear acne faster. If you use tretinoin, discuss other topical medicines, including benzoyl peroxide and salicylic acid, with your doctor before adding them.235

When should you get medical advice?

Contact your doctor if tretinoin causes severe or persistent side effects; call immediately for a rash, hives, or pain at the treatment area. Severe irritation can require stopping a product. Seek a dermatologist for deep cysts or nodules that can scar, or acne that has not cleared with nonprescription treatment. Sensitive skin and eczema need particular care with retinoids. If you are pregnant, planning pregnancy or breastfeeding, discuss retinoid use with your clinician; call your doctor if you become pregnant while using tretinoin.12346

Where this answer comes from

  1. 1Retinol: Cream, Serum, What It Is, Benefits, How To Usemy.clevelandclinic.org
  2. 2Tretinoin Topical: MedlinePlus Drug Informationmedlineplus.gov
  3. 39 things to try when acne won’t clearaad.org
  4. 4Follicular disorders. Topical therapy for acnedermnetnz.org
  5. 5Acne: Diagnosis and treatmentaad.org
  6. 6Topical retinoids (vitamin a creams)dermnetnz.org