4% BHA Advanced Exfoliating Serum Toner

Our 4% BHA Advanced Serum Toner delivers a double concentration of BHA (beta hydroxy acid, aka salicylic acid) to not only exfoliate your skin’s surface, but also clear deep buildup inside pores and target multiple signs of aging.

This non-sticky, leave-on serum is formulated with two barrier-supporting MVPs: glycerin to lock in hydration and adenosine to help soothe skin and soften fine lines. With continued use, skin appears softer, smoother, and more youthful.

At a glance:

• Helps visibly refine enlarged pores
• Smooths rough, bumpy texture
• Softens the appearance of fine lines
• Has an optimal pH range of 3.6-3.9

Apply an even layer over face & neck with fingers or a cotton pad, avoiding the eye area. Leave on; do not rinse.

If you have a salicylate allergy, check with your physician before using any products that contain salicylic acid.

Key Ingredients: Salicylic Acid, Adenosine, Glycerin, Dipotassium Glycyrrhizate, Avena Sativa (Oat) Kernel Extract

All Ingredients: Aqua/Water/Eau (Solvent | Good), Butylene Glycol (Humectant, Texture Enhancer | Good), Dimethicone (Silicone, Emollient | Best), Salicylic Acid (Exfoliant, Humectant | Best), Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer (Suspending/Dispersing Agent, Texture Enhancer, Polymer | Good), Glycerin (Humectant, Texture Enhancer, Solvent | Best), Aminomethyl Propanol (pH Adjuster/Stabilizer | Good), Adenosine (Plant Extracts | Best), Allantoin (Plant Extracts | Best), Dipotassium Glycyrrhizate (Plant Extracts, Antioxidant | Best), Vitis Vinifera (Grape) Seed Extract (Antioxidant, Plant Extracts | Best), Avena Sativa (Oat) Kernel Extract (Plant Extracts, Antioxidant | Best), Punica Granatum Fruit Extract (Antioxidant, Plant Extracts | Best), Sambucus Nigra Fruit Extract (Antioxidant, Plant Extracts | Best), Camellia Oleifera Leaf Extract (Plant Extracts, Antioxidant | Best), Chamomilla Recutita (Matricaria) Flower Extract (Antioxidant, Plant Extracts | Best), Lycium Barbarum Fruit Extract (Antioxidant, Plant Extracts | Best), Peucedanum Graveolens (Dill) Extract (Antioxidant, Plant Extracts | Best), Hydrogenated Lecithin (Emollient, Emulsifier, Suspending/Dispersing Agent | Best), Xanthan Gum (Texture Enhancer, Cleansing Agent, Emulsifier | Good), Citric Acid (pH Adjuster/Stabilizer, Chelating Agent | Good), Disodium EDTA (Chelating Agent | Good), Benzyl Alcohol (Preservative, Solvent, Texture Enhancer | Average), Phenoxyethanol (Preservative | Good)

Ingredient Spotlight:

• Salicylic Acid: Oil-soluble exfoliating ingredient that gently helps slough off dead skin cells and unclogs pores, for softer, smoother texture and tone. Also known as beta hydroxy acid (BHA); Best known for exfoliating properties; Oil solubility lets it exfoliate inside pores
• Adenosine: Known for wrinkle-smoothing and skin-soothing benefits. Adenosine is also naturally present in skin, allowing for ideal biocompatibility. Helps improve the visible appearance of wrinkles; Has soothing properties; Also smooths skin's surface
• Glycerin: A naturally occurring substance in skin that helps retain moisture. It is used in skin care products to help defend against dryness. Found naturally in skin; Helps skin retain moisture; Encourages a healthy look and feel
• Dipotassium Glycyrrhizate: This licorice derivative has strong antioxidant and skin soothing properties. Derived from licorice; Has antioxidant benefits; Strong anti-inflammatory properties
• Avena Sativa (Oat) Kernel Extract: This extract from oats has antioxidant benefits for skin and is well-known for its potent soothing properties. Good source of antioxidants; Exhibits impressive skin-soothing abilities; Suitable for even the most sensitive skin

Journal of European Academy of Dermatology and Venerology,September 2016, issue 9, pages 1480-1490
Phytotherapy Research,August 2015, issue 8, pages 1117-22
Evidence Based Complementary Alternative Medicine,2013, volume 2013, article 827248
Journal of Clinical, Cosmetic and Investigational Dermatology,2015, volume 8, pages 455-461
Indian Dermatology Online Journal,April-June 2013, issue 2, pages 143-146
Molecules,October 2023, pages 1–24
Journal of Cosmetic Dermatology,July 2025, pages 1–7

Is the SKIN PERFECTING 4% BHA Advanced Exfoliating Serum Toner the same formula as the RESIST Advanced Pore-Refining Treatment 4% BHA?

Yes—it’s the same potent-yet-gentle formula you know and love. The only thing that’s changed is the name and packaging. We’ve moved it into our Skin Perfecting line to make it easier to find and to better guide you to the exfoliant that’s right for your skin.

What makes the 4% BHA different from other Paula’s Choice BHA exfoliants?

Like all Paula’s Choice BHAs, the 4% BHA is nonabrasive and works on skin’s surface. The 4% BHA was specifically designed for stubborn texture and visible signs of aging. Its high strength 4% salicylic acid works deep within pores to smooth bumps, refine texture, and improve the look of pores faster, while antioxidants help support firmer looking skin. The silky serum texture glides on smoothly for powerful results without sacrificing comfort.

Who is 4% BHA ideal for?

This 4% salicylic acid serum is suitable for all skin types with stubborn pore congestion, bumps, uneven texture, or early signs of aging. It’s best for experienced exfoliant users who want faster, more noticeable results from deep pore exfoliation.

Does the 4% BHA contain fragrance, dyes or parabens? Is it vegan?

No, the 4% BHA does not contain fragrance, dyes, or parabens, and yes, it is vegan.

Does the 4% BHA have a noticeable scent?

While Paula’s Choice products are fragrance-free, each product may have a unique scent due to its ingredients. Any noticeable scent dissipates quickly after application.

Why is 4% BHA called a toner?

While 4% BHA is an exfoliant, many people search for exfoliants as “clarifying toners” or “exfoliating toners” as toners and exfoliants are often used interchangeably by customers (after cleansing and before treatment). Using the term toner helps make it easier to find. The formula and how you use it haven’t changed—it’s still a leaveon exfoliant applied after cleansing and your hydrating toner (if applicable).

Is the 4% BHA safe/suitable for acne-prone/breakout-prone skin?

Yes, the 4% BHA is especially good for acne and breakoutprone skin. Its oilsoluble salicylic acid works inside pores to help clear congestion while the formula’s soothing antioxidant plant extracts aid tolerability.

Is the 4% BHA safe/suitable for sensitive skin or redness-prone skin?

This will vary by individual. While the formula includes hydrating and soothing ingredients to help minimize dryness or tightness, this is a high strength 4% BHA exfoliant and may be too active for some sensitive or redness-prone skin types. We recommend patch testing first. If your skin is easily reactive, consider our 1% BHA Gentle Exfoliating Gel Toner which is specifically formulated for sensitive, redness-prone skin.

Can I use 4% BHA during pregnancy or while breastfeeding?

No, this amount of salicylic acid is typically not advised for routine use during pregnancy or breastfeeding; however, discuss the option of occasional (once or twice weekly use) with your health care provider and follow their advice.

If I use a retinoid product, can I add the 4% BHA to my routine?

Yes, although it’s best to apply it at a separate time from your retinoid until you know how your skin responds to a 4% concentration of BHA. Even if all goes well with applying these products at a separate time, you may find switching to applying them together to be too much. If this occurs, simply go back to applying them separately, or consider using the 4% BHA less often, alternating with one of our other BHA (or AHA) exfoliants.

Be sure your daytime routine includes a broad-spectrum sunscreen rated SPF 30 or greater.

Does the 4% BHA cause purging?

It can but not for everyone, and when it does happen, it’s temporary. BHA (salicylic acid) can sometimes temporarily cause skin purging due to its oil solubility, which allows it to penetrate deep into pores and break up trapped skin cells. This speeds up cell turnover, bringing clogs to the surface, indicating the exfoliant is working properly.