Understanding Chemical Exfoliants: A Practical Guide
Chemical exfoliants have become a cornerstone of modern skincare and for good reason. Unlike physical scrubs, acids work at a cellular level to loosen the bonds holding dead skin cells together, revealing smoother, more radiant skin beneath. But not all acids are created equal. AHAs and BHAs each have a distinct chemistry, a distinct depth of action, and a distinct sweet spot when it comes to skin type and concern.
This guide is designed to help you make an informed, confident choice not to diagnose your skin or replace the advice of a qualified dermatologist or skincare clinician.
What Are AHAs?
AHAs (Alpha Hydroxy Acids) are water-soluble acids derived primarily from natural sources such as sugarcane, milk, and fruit. The most common AHAs used in skincare are:
- Glycolic acid — smallest molecule, deepest penetration, most studied
- Lactic acid — gentler, hydrating, well-tolerated by sensitive skin
- Mandelic acid — largest molecule, slowest absorption, good for acne-prone and sensitive types
- Malic acid and tartaric acid — often used in combination formulas
Because AHAs are water-soluble, they work primarily on the surface of the skin. They are especially effective at addressing concerns that originate or present in the upper layers of the epidermis.
AHAs Are Best For:
- Dull, uneven skin tone and texture
- Dry or dehydrated skin (particularly lactic acid)
- Fine lines and surface-level signs of ageing
- Hyperpigmentation, post-inflammatory discolouration, and uneven radiance
- Normal-to-dry skin types that can handle water-based actives
What Are BHAs?
BHAs (Beta Hydroxy Acids) are oil-soluble acids, with salicylic acid being by far the most widely used in skincare. Because they are lipid-soluble, BHAs can travel through the sebum (oil) in your pores making them uniquely effective at working below the surface of the skin, inside the follicle itself.
BHAs Are Best For:
- Oily and combination skin types
- Congested pores, blackheads, and whiteheads
- Acne-prone skin, including inflammatory breakouts
- Enlarged-looking pores
- Skin that is prone to bumpiness or milia
If your primary skin concerns include persistent congestion, frequent breakouts, or visibly enlarged pores, a well-formulated BHA serum is often the more targeted choice. Our Clarifying BHA Serum is designed precisely for this. A targeted, daily-friendly formula that works within the pore to clarify and refine over time.
AHA vs BHA: A Side-by-Side Comparison
| AHA | BHA | |
|---|---|---|
| Solubility | Water-soluble | Oil-soluble |
| Where it works | Surface of the skin | Inside the pore |
| Best for | Dullness, tone, texture, dryness | Oiliness, congestion, breakouts |
| Skin type | Normal to dry | Oily to combination |
| Sensitivity | Moderate (lactic/mandelic gentler) | Generally well tolerated |
| Sun sensitivity | Yes — increases photosensitivity | Mild increase |
Can you Use Both?
Yes, many people benefit from using both AHAs and BHAs, particularly those with combination skin or multiple concerns. The key is in the sequencing and frequency.
Sequencing Guidelines:
- Do not layer AHA and BHA in the same step. Applying both simultaneously can compromise the skin barrier and cause irritation.
- Alternate by evening. Use your BHA on Monday, Wednesday, and Friday evenings; use your AHA on Tuesday and Thursday evenings. Rest the skin on weekends if you are new to acids.
- Never use with retinoids in the same step unless directed by a clinician. Both acids and retinoids are active ingredients that increase cellular turnover combining them without guidance can over-exfoliate the skin.
- Always apply to dry skin, 20–30 seconds after cleansing, unless your formulation specifies otherwise.
- Wait 10–15 minutes before layering subsequent products to allow the pH environment to stabilise.
Important Safety Precautions
Patch Test First
Before introducing any new acid into your routine, perform a patch test. Apply a small amount of the product to a discreet area like the inner forearm or behind the ear and wait 24–48 hours. If you experience redness, burning, or itching beyond a brief, mild tingling, discontinue use and consult a skincare professional.
Sunscreen Is Non-Negotiable
Both AHAs and BHAs increase your skin's sensitivity to UV radiation. This is well-documented for AHAs in particular. Using a broad-spectrum SPF 30 or higher every morning is not optional when acids are part of your evening routine, it is a fundamental requirement to protect your results and your skin's long-term health.
Start Low, Go Slow
If you are new to chemical exfoliants, begin with lower concentrations (5–8% AHA or 0.5–2% BHA) used once or twice per week. Gradually increase frequency only when your skin has demonstrated tolerance over several weeks.
When to Consult a Clinician
This guide is educational and general in nature. It does not constitute medical or dermatological advice. You should consult a qualified dermatologist, aesthetician, or skincare clinician if:
- You have a diagnosed skin condition such as rosacea, eczema, or psoriasis
- You are pregnant or breastfeeding (salicylic acid in particular should be discussed with your doctor)
- You are currently using prescription topicals, including tretinoin or antibiotic creams
- You experience persistent irritation, breakouts, or skin barrier disruption after introducing acids
- You are unsure which concern to prioritise or which acid concentration is appropriate for your skin
The Irawo Beauty Approach
At Irawo Beauty, we believe that informed skincare is empowered skincare. Understanding why an ingredient works is just as important as knowing how to use it. Whether you are beginning your exfoliant journey or refining an established routine, we are here to guide you with formulations that are intentional, effective, and worthy of your skin.
If congestion, breakouts, or enlarged pores are your primary concern, explore our Clarifying BHA Serum. Formulated to work within the pore, gently and consistently, for visibly clearer skin over time.