Skincare acids sound intimidating, but they are among the most effective and well-evidenced active ingredients available. Once you understand how each type works and which conditions it addresses, you can use them with confidence — and see genuinely transformative results in skin texture, tone, and clarity. This guide covers the three most important categories for Irish skin: AHAs, BHAs, and azelaic acid.
Why Exfoliation Matters for Irish Skin
The skin naturally renews itself every 28–40 days by generating new cells at the base of the epidermis and shedding dead cells at the surface. As we age, and under the influence of environmental stressors like UV, wind, and pollution, this turnover process slows. Dead skin cells accumulate on the surface, leading to dullness, uneven texture, clogged pores, and reduced absorption of serums and moisturisers.
For Irish skin, which contends with high humidity in summer, hard water throughout the year, and a UV profile that produces damage without always producing a visible tan (UV damage is cumulative and occurs through cloud cover), regular exfoliation is particularly valuable. The American Academy of Dermatology recommends chemical exfoliation as a gentler, more even alternative to physical scrubs — particularly for sensitive, ageing, or post-acne skin.
What Are AHAs (Alpha Hydroxy Acids)?
Alpha hydroxy acids are water-soluble acids derived mainly from natural sources. They work on the skin’s surface, dissolving the protein bonds between dead skin cells so they shed more easily, revealing brighter, smoother skin underneath. The most commonly used AHAs in skincare are:
- Glycolic acid (from sugarcane) — the smallest AHA molecule, with the deepest penetration and highest efficacy for improving fine lines, texture, and sun damage. Best for resilient, non-sensitive skin. Start at low concentrations (5–10%) and build gradually.
- Lactic acid (from milk fermentation) — a larger molecule than glycolic, making it gentler and less likely to cause irritation. Also a humectant, meaning it hydrates while it exfoliates. Particularly well-suited to dry Irish skin that needs exfoliation without barrier disruption.
- Mandelic acid (from bitter almonds) — the gentlest of the commonly used AHAs, with antibacterial properties that make it useful for acne-prone as well as sensitive skin.
Research published in the Archives of Dermatology demonstrated that long-term AHA use significantly improves skin texture, increases epidermal thickness, and reduces the appearance of sun damage — effects that build progressively over months of consistent use.
What Are BHAs (Beta Hydroxy Acids)?
Beta hydroxy acids are oil-soluble, which is their key differentiator from AHAs. While AHAs work on the skin surface, BHAs can penetrate into the oil-filled pore, dissolving the sebum and dead cell buildup that leads to blackheads, whiteheads, and congestion. Salicylic acid is the primary BHA used in skincare and has both exfoliating and anti-inflammatory properties.
For Irish skin with congestion, combination skin, or acne-prone tendencies, a BHA serum or toner used two to three times per week can significantly clear blocked pores over four to six weeks. Salicylic acid also reduces redness and is less irritating for acne-prone sensitive skin than physical exfoliants or high-strength AHAs. It is not appropriate for those with aspirin sensitivity.
What Is Azelaic Acid?
Azelaic acid is a naturally occurring dicarboxylic acid found in grains (wheat, rye, barley). Often grouped with AHAs and BHAs in skincare discussions, it works through distinct mechanisms: it’s anti-inflammatory, antibacterial, and a powerful melanin production inhibitor. This makes it effective for three conditions that are particularly common in Irish skin:
- Rosacea — Ireland has one of the highest rates of rosacea globally, linked to the prevalence of Fitzpatrick I and II skin types. Azelaic acid’s anti-inflammatory properties make it a first-line cosmetic intervention for rosacea-associated redness and papules.
- Post-inflammatory hyperpigmentation (PIH) — the dark marks left after blemishes. Azelaic acid inhibits the enzyme tyrosinase, reducing melanin overproduction in healing skin.
- Acne — its antibacterial action targets Cutibacterium acnes while its anti-inflammatory effect reduces associated redness and swelling.
Azelaic acid is also one of the few effective exfoliating actives considered safe to use during pregnancy and breastfeeding — when retinoids, high-dose salicylic acid, and certain other actives are contraindicated. A clinical review in Dermatologic Therapy confirms azelaic acid’s efficacy for both acne and rosacea with a favourable safety profile for long-term use.
How to Introduce Acids Safely into Your Irish Skincare Routine
The most important rule is to introduce acids one at a time, starting no more than twice a week, and to always follow with SPF the following morning (acids increase photosensitivity). Do not combine multiple exfoliating acids on the same night until your skin has fully adjusted over several months. A gentle, hydrating cleanser before and a nourishing serum and barrier-repair moisturiser afterwards will prevent over-exfoliation.
For Irish autumn and winter — when the skin barrier is already under pressure from wind, cold, and indoor heating — reduce acid frequency if you experience dryness, tightness, or increased sensitivity. The goal is exfoliated skin, not a depleted barrier. Always apply a hydrating serum and rich moisturiser after any acid treatment; see our guide to Hydrating Serums: The One Step You’re Probably Skipping for recommendations.
Which Acid Is Right for Your Skin Type?
- Dull, dry, or uneven skin in Ireland: Start with lactic acid at 5–10%. It exfoliates while simultaneously hydrating, making it the gentlest entry point for dry, dehydrated Irish skin.
- Congested pores, blackheads, or acne: Salicylic acid (BHA) at 1–2% used 2–3 nights per week. Follow with a fragrance-free moisturiser.
- Redness, rosacea, or hyperpigmentation: Azelaic acid at 10% (available over the counter in Ireland) or 15–20% (prescription strength). Can be used morning or evening.
- Ageing skin wanting texture improvement: Glycolic acid at 5–10%, used gradually, produces the most dramatic results for fine lines and sun damage over time.
- Sensitive skin: Mandelic acid at low concentration or azelaic acid — both are significantly gentler than glycolic or salicylic acid.
For the complete context on how acids fit into your skincare routine, see our Complete Skincare Routine for Irish Skin. Pair your acid step with our serums and moisturisers to maintain barrier health throughout your exfoliation routine. Also see our guide on How to Exfoliate Your Face for more detailed techniques.
Frequently Asked Questions
Can I use AHAs and BHAs together?
You can, but it’s best to introduce them separately and only combine once your skin has fully adjusted to each individually. For most people, alternating them on different evenings — rather than using both on the same night — gives the best results without over-exfoliating the barrier.
Do I need to use SPF when using skincare acids?
Yes, every morning, regardless of whether you used an acid the previous evening. AHAs and BHAs increase the skin’s photosensitivity by removing the outer protective dead cell layer. Daily SPF 30 or higher is non-negotiable with any acid routine, including in Ireland’s overcast climate.
Can I use acids if I have sensitive skin?
Yes, with care. Start with mandelic acid or low-concentration lactic acid, maximum twice weekly. Azelaic acid is also well-suited to sensitive skin, including rosacea-prone complexions. Avoid glycolic acid initially as its small molecule size and deep penetration makes it the most likely to cause irritation.
Why does azelaic acid feel gritty or tingly when applied?
A mild tingling sensation on application is normal and typically subsides within seconds. A gritty texture in some formulations comes from the azelaic acid particles not being fully dissolved — this is normal in certain suspension-type formulas and does not affect efficacy. If stinging is prolonged or severe, dilute by applying over a light moisturiser or reduce frequency.
How long does it take to see results from skincare acids?
AHAs typically produce visible texture improvement within 2–4 weeks. For hyperpigmentation and rosacea, azelaic acid usually shows noticeable results after 8–12 weeks. BHA for congestion often shows improvement within 4–6 weeks. Consistency matters far more than frequency — twice-weekly use sustained over three months outperforms daily use for one month and then abandonment.