What is the difference between AHA, BHA, PHA ?

August 20, 2024

When it comes to skincare, there are three key ingredients that are often mentioned: AHA, BHA, and PHA. But what exactly are these acids and what sets them apart from each other? Let's delve into the science behind these popular skincare ingredients.

What is AHA?

AHA stands for Alpha Hydroxy Acid. This group of acids is derived from fruits and milk and is known for its exfoliating properties. AHA works by breaking down the bonds between dead skin cells, helping to reveal smoother and brighter skin. Common types of AHA include glycolic acid and lactic acid.

What is BHA?

BHA stands for Beta Hydroxy Acid. The most common BHA in skincare is salicylic acid. Unlike AHA, BHA is oil-soluble, which means it can penetrate deep into the pores to unclog them. This makes BHA a great ingredient for those with oily or acne-prone skin. BHA also has anti-inflammatory properties, making it suitable for sensitive skin.

What is PHA?

PHA stands for Polyhydroxy Acid. PHA is a newer generation of exfoliating acids that are known for being gentler on the skin compared to AHA and BHA. PHA works by exfoliating the skin's surface while also providing hydration and antioxidant benefits. This makes PHA a great option for those with sensitive skin or those looking for a milder exfoliation option.

In summary, AHA, BHA, and PHA are all effective exfoliating acids, but they each have unique properties that make them suitable for different skin types and concerns. Whether you're looking to brighten your complexion, unclog pores, or gently exfoliate sensitive skin, there is an acid out there for you. Remember to always patch test new products and consult with a skincare professional to determine the best acid for your skin.

What not to pair with the active ingredients?

Retinol should not be mixed with exfoliating ingredients such as AHAs and BHAs. Additionally, retinol should not be used with vitamin C or Benzoyl peroxide products as this can cause irritation. If you do want to use a product containing vitamin C, be sure to apply it at a different time of day than your retinol product.
Niacinamide is used to treat hyperpigmentation and reduce fine lines and wrinkles, while AHA's & BHA's are chemical exfoliants. To understand why niacinamide shouldn’t be mixed with AHAs and BHAs, you need to consider ph. “AHAs and BHAs usually have a pH around 3.0 to 4.0, while niacinamide usually has a pH around 5.0 to 7.0,”.
However, you don’t have to choose between acids and niacinamides. it’s fine to include both niacinamide and AHAs or BHAs in your skincare routine as long as you don’t use one right after another. “For maximum benefit, the ingredients should be applied at different times of the day, on alternating days, or at least 30 minutes apart,”.
Vitamin C & AHA/BHA - Just as AHAs and BHAs can interfere with the pH levels of niacinamide, the acids can do the same with vitamin C. Since vitamin C is pH-sensitive, using other products without stabilized pH right before or after vitamin C can degrade the antioxidant properties and decrease the skin’s absorption of the ingredient“. So pay attention to what cleanser you are using with your vitamin C in the morning,” . A pH-balanced cleanser, like HaruHaru WONDER - Black Rice Moisture 5.5 Soft Cleansing gel.