AHAs vs BHAs… what’s the difference?

You will have most likely seen AHAs and BHAs pop up in the ingredients list of your favourite face masks, cleansers, moisturisers and toners, but what exactly are they and what’s the difference between them?

Both are hydroxy acids that are effective methods of deep exfoliation, however they are both considerably different.


Alpha Hydroxy Acids (AHA) contain molecules that love water and help improve your skins surface moisture level.

  • The effects of AHAs are primarily seen on the skin’s surface, therefore are helpful if you have surface-level skin concerns like hyperpigmentation.
  • The most common AHAs are Glycolic Acid and Lactic Acid.
  • AHAs work by breaking down the glue holding your skin cells together, urging along the skin’s natural shedding process, ensuring there are new, fresh skin cells on top as opposed to old, troublesome ones.
  • AHAs are great for those with dry and/or flaky skin, hyperpigmentation (age spots, melasma, and scars), fine lines and wrinkles and a dull complexion.


Beta Hydroxy Acids (BHA) on the other hand contain molecules that love oil rather than water.

  • They are better suited to those with oily, acne-prone skin as they can bypass the oil that clogs pores and dissolve the mix of sebum and dead skin that leads to acne, as well as stabilise the lining of the pore.
  • The most common BHA is Salicylic Acid.
  • BHAs clear up blackheads and have anti-inflammatory and antibacterial properties.
  • BHAs also exfoliate the top layer but are best bought for their deep penetrative qualities.
  • They are best suited to skin that is acne-prone, blackhead-prone and combination to oily.

What BHAs and AHAs have in common:

They both:

  • Hydrate skin
  • Diminish the look of lines and wrinkles
  • Make skin feel firmer
  • Improve the look of dull, uneven skin tone
  • Smooth rough, bumpy texture

Is it safe to use both together?

It is safe to use AHAs and BHAs together. They target different actions so they have different benefits – BHAs disrupt the connections between dead cells whilst AHAs cause dead cells to detach and slough away, therefore they can indeed work well together. However you need to be careful to not overdo it. If your skin starts to react, stop immediately.

My top tips for using AHAs and BHAs

  • Start introducing acids into your skincare routine slowly. Don’t start using 3 different acids every day of the week and expect incredible results, it’s most likely your skin will react very aggressively! Perhaps introduce an acid 2-3 times a week and slowly build up to around 5-7 times a week (depending on your skin type of course).
  • SPF!! Don’t forget to wear your SPF in the morning after using a chemical exfoliant as skin will be especially sensitive to UVA rays. The skin is more vulnerable to damage and pigmentation following these types of treatments which means pigmentation can potentially get worse if SPF is not used regularly.
  • I tend to find that using AHA in the morning (to gently exfoliate my skin) and BHA at night (to get deeper into the pores and clear out build-up from the day) works well.
  • If you have very sensitive skin or peeling skin, please avoid using acids.
  • If you are under the age of 20, also avoid using acids on your skin. Your skin isn’t quite ready for them yet.

My favourite AHA and BHA products

REN Ready Steady Glow Toner

The perfect everyday toner. This lactic-based toner is so refreshing and makes skin go from dull and matte to glowing and dewy. There’s also no irritation involved!

Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant

I bang on and on about this product, but it is seriously good for acne-prone skin like mine. It has a great balanced concentration of spot-reducing salicylic acid with soothing green tea to decongests pores and minimises breakouts. I noticed results within 4 weeks!

The Ordinary Glycolic Acid 7% Toning Solution

This gentle yet effective toner contains glycolic acid (an AHA) to gently exfoliate the skin and improve its texture. This was the first AHA product I tried and I still use it. It’s constantly sold out so that says it all!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s