Azelaic Acid: Over-the-Counter vs Prescription, and Why Your Skin Barrier Matters

Azelaic acid has had a big year on social media, and for good reason. It is one of the most useful, well-tolerated topical ingredients we have for acne, rosacea and the dark marks acne leaves behind. But in our clinics in Dublin, Limerick and London we are also seeing the other side of the trend: a noticeable rise in perioral dermatitis and irritated, damaged skin in patients who have layered azelaic acid with topical tretinoin on the advice of social media, without doing anything to protect their skin barrier.

This guide explains the difference between the azelaic acid you can buy and the strengths we prescribe, who should use which, and how to use it without wrecking your skin.

What azelaic acid is

Azelaic acid is a naturally occurring dicarboxylic acid. It works in several ways at once, which is why it is so versatile:

• Antibacterial: it reduces acne-causing bacteria without the resistance problems of topical antibiotics.

• Unclogs pores: it normalises how skin cells shed inside the follicle, helping prevent blackheads and whiteheads.

• Anti-inflammatory: it calms the redness and bumps of acne and rosacea.

• Evens pigment: it slows overactive pigment cells, while largely leaving normal skin alone. This makes it particularly useful for post-inflammatory hyperpigmentation, the dark marks acne leaves, especially in skin of colour.

Over-the-counter vs prescription: what is the difference?

In the UK and Ireland, prescription azelaic acid comes as a 15% gel (Finacea) and a 20% cream (Skinoren). Over-the-counter products are usually 10% or lower.

The difference is not only strength. Prescription products are licensed medicines, made to pharmaceutical standards, tested in clinical trials for a specific condition, and come with a clinician who can judge whether azelaic acid is actually the right treatment for you.

What the evidence shows

Most of the strong evidence is for the 15% and 20% prescription formulations:

• Acne: in comparative trials, 20% azelaic acid cream performed similarly to 0.05% tretinoin and 5% benzoyl peroxide, though it tends to work more slowly. Expect 8 to 12 weeks.

• Rosacea: 15% gel is an established first-line option for the bumps and pustules of rosacea, with trial results comparable to topical metronidazole.

• Pigmentation: for melasma, 20% azelaic acid has performed comparably to 4% hydroquinone in trials, with fewer concerns for long-term use.

• Pregnancy: very little is absorbed through the skin, so it is generally considered one of the safer options for acne in pregnancy and breastfeeding. Always discuss this with your clinician first.

So, is it as good as social media suggests? It is a genuinely excellent, evidence-based ingredient, but it is a steady performer rather than a miracle. It is slower than tretinoin for acne, and a 10% cosmetic serum is not the same as a prescription treatment.

Who should use what

Tretinoin, azelaic acid and the rise in perioral dermatitis

Azelaic acid and tretinoin can work well together. Many dermatologists combine them for acne and acne marks. The problem is how they are being combined. Both commonly cause stinging, burning and dryness in the first few weeks. Applied together, every night, from day one, on skin that is not being moisturised or protected, the irritation adds up and the skin barrier breaks down.

A damaged barrier lets water out and irritants in. The result is red, tight, flaky, stinging skin, and in a growing number of the patients we see, perioral dermatitis: clusters of small red bumps and scaling around the mouth, nose and sometimes eyes.

The usual reaction is to reach for more products, or a hydrocortisone cream from the pharmacy. Steroid creams are one of the best-known triggers of perioral dermatitis. They may calm it briefly, but it typically comes back worse.

If you think you have perioral dermatitis: stop your actives, do not apply steroid creams, strip your routine back to a gentle cleanser, a simple moisturiser and sunscreen, and see a dermatology professional. It is very treatable, but it usually needs prescription treatment and patience.

Do not do's with azelaic acid

• Do not start azelaic acid and tretinoin on the same night. Introduce one at a time.

• Do not layer it with exfoliating acids (glycolic, lactic, salicylic), scrubs or peels while your skin adjusts.

• Do not apply it to broken, sunburnt or already irritated skin.

• Do not apply it close to the eyes, the corners of the mouth or inside the nostrils.

• Do not use more product to get faster results. A pea-sized amount for the whole face is enough.

• Do not treat irritation with hydrocortisone or other steroid creams unless a doctor has prescribed it.

• Do not skip sunscreen, especially if you are treating pigmentation.

• Do not self-treat persistent redness. Rosacea, perioral dermatitis and acne need different plans.

What to look for on the label

• The real ingredient: check the ingredient list says azelaic acid, not only a derivative.

• The right base: gels suit oily, acne-prone skin; creams suit dry or sensitive skin.

• Barrier-friendly companions: panthenol (vitamin B5), glycerin, niacinamide, ceramides and hyaluronic acid.

• Fewer irritants: avoid fragrance, essential oils and high alcohol content. If you are sensitive, note that propylene glycol can sting.

How to introduce it safely

1. Get your skin calm first. If it is already red or flaky, repair the barrier for two to four weeks before adding any active.

2. Start azelaic acid every other evening on clean, completely dry skin, then build to daily, and to twice daily if advised.

3. Apply a barrier-supporting moisturiser afterwards. If it stings, apply moisturiser first as a buffer.

4. If you are also prescribed tretinoin, add it only once azelaic acid is comfortable. Alternate nights at first, or use azelaic acid in the morning and tretinoin at night.

5. Mild tingling in the first few weeks is common. Burning that persists, swelling, or a rash around the mouth is a reason to stop and seek advice.

6. Wear SPF 30 or higher every day.

Supporting your barrier alongside treatment

REFORM Skincare does not make an azelaic acid product. Where we focus instead is on keeping the skin barrier healthy while patients use active treatments like azelaic acid and tretinoin:

• Vitamin B5 Gel and Phytobotanical Gel: lightweight serums that soothe and calm a stressed, irritated barrier.

• Intensive Moisturiser: niacinamide and hyaluronic acid to restore hydration and support barrier function. Pairs well with either gel.

• Skin Barrier Repair Cream: a high-strength urea cream developed for eczema and psoriasis. It can also help very dry skin that has been stripped by harsh routines. Use it on dry, intact skin rather than on acutely inflamed or broken skin, where it may sting.

Transparency: REFORM Skincare was founded by Dr Naomi Mackle and is the in-house cosmeceutical range of Adare Dermatology Clinics. Recommendations are always made on clinical need.

Summary

Azelaic acid is one of the most useful, gentlest-to-live-with ingredients in dermatology, especially for acne marks, rosacea and pigmentation. A 10% product is a reasonable start for mild concerns; prescription 15% gel and 20% cream are the strengths with the evidence for acne, rosacea and melasma. The ingredient is rarely the problem. The routine around it is. Introduce actives one at a time, protect your barrier, never self-treat irritation with steroid creams, and if your skin is reacting, book a review rather than adding another product.

This article is for general information and does not replace a consultation. If you are pregnant, breastfeeding or using prescription treatments, speak to your clinician before changing your routine.