AHA vs. BHA vs. PHA: Which Acid Exfoliant Is Best for Your Skin Type?
By Neutrogenahub | Published: 2026-05-29
Category: How-to Guides
Confused by chemical exfoliants? Our complete guide breaks down AHA, BHA, and PHA acids—how they work, which skin types they suit best, and how to choose the right one for a glowing, healthy complexion.
Chemical exfoliation has revolutionized modern skincare, offering a gentle yet effective way to reveal smoother, brighter, and more even-toned skin. But with so many acids on the market—AHA, BHA, PHA—it's easy to feel overwhelmed. Each type works differently, targets distinct concerns, and suits specific skin types. In this comprehensive guide, we'll break down the differences between AHA, BHA, and PHA, help you identify which one matches your skin's needs, and show you how to incorporate them safely into your routine. Whether you're battling breakouts, fine lines, or dullness, understanding these exfoliants is your first step toward a radiant complexion.
What Are Chemical Exfoliants and Why Use Them?
Unlike physical scrubs that manually slough off dead skin cells, chemical exfoliants use acids to dissolve the bonds that hold dead cells together. This process reveals fresh skin underneath without the micro-tears that abrasive scrubs can cause. Regular use of the right chemical exfoliant can:
- Improve skin texture and smoothness
- Minimize the appearance of pores
- Reduce fine lines and wrinkles
- Fade dark spots and hyperpigmentation
- Enhance absorption of other skincare products
But not all acids are created equal. Let's dive into the three main categories.
AHA (Alpha Hydroxy Acids): The Brightening Powerhouse
AHAs are water-soluble acids that work on the skin's surface. They are best known for exfoliating the top layer of skin, making them ideal for addressing surface-level concerns like dullness, uneven texture, and mild hyperpigmentation. Common AHAs include glycolic acid (derived from sugar cane, the most potent) and lactic acid (from milk, which also offers gentle hydration).
Best For: Dry, Sun-Damaged, or Aging Skin
Because AHAs do not penetrate oil, they are less effective for oily or acne-prone skin. However, they are excellent for:
- Improving skin radiance and glow
- Reducing the appearance of fine lines
- Fading sunspots and post-inflammatory hyperpigmentation
- Boosting collagen production over time
If you have dry or mature skin, a gentle AHA like lactic acid can provide exfoliation while also attracting moisture. For a deeper resurfacing effect, glycolic acid is a go-to. When using AHAs, always pair them with a broad-spectrum sunscreen, as they can increase sun sensitivity.
BHA (Beta Hydroxy Acid): The Pore-Clearing Specialist
BHA, most commonly salicylic acid, is oil-soluble. This unique property allows it to penetrate deep into pores, dissolving excess sebum, dead skin cells, and debris that cause blackheads, whiteheads, and breakouts. BHA is also anti-inflammatory, making it particularly soothing for red, irritated acne.
Best For: Oily, Acne-Prone, or Combination Skin
BHA is the acid of choice for anyone struggling with congestion, enlarged pores, or active acne. It excels at:
- Unclogging pores and preventing future breakouts
- Reducing blackheads and whiteheads
- Calming inflamed pimples
- Controlling oil production without stripping the skin
For acne-prone skin, salicylic acid is a star ingredient. You can find it in cleansers, toners, and spot treatments. For example, the Neutrogena Clear Face Sunscreen Lotion for Acne-Prone Skin, Broad Spectrum SPF 30 Facial Sunscreen for Oily Skin, Fragrance- & Oxybenzone-Free Water Resistant, 3 fl. oz is a fantastic daily SPF that won't clog pores—perfect to layer after your BHA treatment. And for gentle cleansing, the Neutrogena Facial Cleansing Bar for Acne-Prone Skin, Gentle Non-Medicated Daily Cleanser, Non-Comedogenic Transparent Soap with Glycerin, No Dyes or Detergents, 3.5 oz provides a non-stripping clean that supports a balanced complexion.
PHA (Polyhydroxy Acids): The Gentle Giant
PHAs are the newer, more sophisticated cousins of AHAs. They have a larger molecular structure, which means they penetrate the skin more slowly and gently. This makes PHAs significantly less irritating while still providing effective exfoliation and hydration. Common PHAs include gluconolactone and lactobionic acid.
Best For: Sensitive, Reactive, or Dehydrated Skin
PHAs are perfect for those who find AHAs too harsh or who have conditions like rosacea or eczema. Benefits include:
- Gentle exfoliation without stinging or redness
- Humectant properties that attract moisture to the skin
- Antioxidant protection against environmental damage
- Suitable for daily use even on compromised skin barriers
If your skin is easily irritated but you still want the benefits of chemical exfoliation, start with a PHA. You can also use PHAs as a stepping stone to build tolerance before moving to AHAs or BHAs.
AHA vs. BHA vs. PHA: Side-by-Side Comparison
| Feature | AHA | BHA | PHA |
|---|---|---|---|
| Solubility | Water-soluble | Oil-soluble | Water-soluble |
| Where it works | Skin surface | Inside pores | Skin surface (gentle) |
| Best for | Dullness, fine lines, sun damage | Acne, clogged pores, oiliness | Sensitivity, dehydration, redness |
| Irritation potential | Moderate to high | Low to moderate | Very low |
| Hydration bonus | Lactic acid is hydrating | None (can be drying) | Yes, humectant properties |
| Typical concentration | 5-10% (OTC) | 0.5-2% (OTC) | 4-8% (OTC) |
How to Choose the Right Acid for Your Skin Type
Oily and Acne-Prone Skin: BHA First
If your main concerns are breakouts, blackheads, and shiny skin, start with a BHA. Salicylic acid will penetrate your pores and keep them clear. You can use it in a leave-on serum or toner once daily. Avoid combining with other strong actives initially to prevent over-exfoliation.
Dry and Aging Skin: AHA for Radiance
For mature or dry skin, AHAs like glycolic or lactic acid will help shed dead cells that make skin look dull. Lactic acid is especially gentle and adds moisture. Use 2-3 times per week and always follow with a rich moisturizer and SPF.
Sensitive and Reactive Skin: PHA Is Your Friend
If even gentle AHAs cause redness, switch to a PHA. It exfoliates without compromising your barrier. You can use it daily without fear of irritation. Over time, you may be able to introduce a mild AHA once your skin builds tolerance.
Combination Skin: Mix and Match Smartly
You can use different acids on different areas of your face. For example, apply BHA to your T-zone where pores are larger and oilier, and AHA or PHA to your cheeks if they are drier. Just never layer two leave-on acids at the same time—alternate them on different days or use one in the morning and another at night.
How to Safely Incorporate Chemical Exfoliants Into Your Routine
Start low and go slow. Begin with the lowest concentration available and use it only once or twice a week. Gradually increase frequency as your skin adjusts. Always apply exfoliants to clean, dry skin and wait 15–20 minutes before layering other products to minimize irritation.
Key rules to remember:
- Never combine two different exfoliating acids in the same routine unless directed by a dermatologist.
- Avoid using retinol or vitamin C on the same night as a strong AHA or BHA.
- Always wear sunscreen during the day—chemical exfoliants increase photosensitivity.
- Listen to your skin: if you experience stinging, peeling, or redness, reduce frequency or switch to a gentler acid.
Common Myths About Chemical Exfoliants
Myth: Chemical exfoliants thin your skin. Truth: When used correctly, they actually stimulate collagen production and strengthen the skin over time. They only remove the outermost dead layer, not healthy skin.
Myth: You can't use acids if you have sensitive skin. Truth: PHAs are specifically designed for sensitive skin. Even AHAs and BHAs can be tolerated at low concentrations if introduced gradually.
Myth: More acid equals better results. Truth: Over-exfoliating damages your moisture barrier, leading to irritation, breakouts, and dehydration. More is not better.
Conclusion: Your Exfoliation Roadmap
Choosing between AHA, BHA, and PHA doesn't have to be complicated. Identify your primary skin concern—acne, aging, or sensitivity—and match it to the acid that addresses it best. Remember, consistency matters more than strength. A gentle PHA used daily will yield better long-term results than a harsh AHA used incorrectly.
Ready to refine your skincare routine? Explore our full range of gentle cleansers and targeted treatments designed to complement your exfoliation journey. Start with a non-comedogenic foundation like the Neutrogena Hydro Boost Lightweight Hydrating Facial Cleansing Gel, Gentle Face Wash & Makeup Remover with Hyaluronic Acid, Hypoallergenic & Non Comedogenic, Refill Pouch, 16 fl. oz to prep your skin before any acid treatment. Your clearest, most radiant skin is just a few smart choices away.



