Dropping Acid | AHA's, BHA's and PHA's with @rithink_skin

This week, Ria Biyani - of @rithink_skin, very generously put together this super DUPER informative guide on acids. This one's been a highly requested piece, and we hope it enables you all to equip yourself with more knowledge as you make your skin care purchases/decisions. Enjoy!

Let’s be real, all of us dream of having clear, smooth, glowing skin. That’s the ultimate goal, right? In my few years of experimenting with skincare, testing new products and learning about how ingredients work on our skin, exfoliation, and more specifically chemical exfoliators have really stood out in their ability to target and treat multiple skin concerns. Put simply, exfoliation is the process of removing dead skin cells from the top layers of our skin. While our skin naturally goes through a cell turnover cycle every 28 days, this slows down as we age. A build-up of dead skin cells can result in many different skin issues including acne, fine lines, wrinkles, uneven texture & dullness. Exfoliating skincare products assist our skin’s natural exfoliation process to reveal smoother, brighter, plumper and clearer skin. It also allows your other skincare products to penetrate better. Exfoliation is an essential part of any balanced skincare routine and should be done 1-3 times a week to keep your skin looking healthy!


If you have ever used salicylic acid to treat a breakout or gone to a dermatologist for a chemical peel, you have experienced the wonderful world of chemical exfoliators. They work by dissolving the glue that holds unwanted dead skin cells on the skin’s surface and are suitable for all skin types! There are three main types – Alpha Hydroxy Acids (AHAs), Beta Hydroxy Acids (BHAs) and Poly Hydroxy Acids (PHAs). They can be found in a variety of different formulations like cleansers, toners, serums and moisturizers. It’s important to note that you won’t see results overnight! These exfoliants work on the deeper layers on the skin and will require patience and consistency to show visible results.

AHAs, are water-soluble acids that work on the skin’s surface to slough away dead skin cells. It includes ingredients like Glycolic acid (from sugar cane), Lactic acid (from milk) and Mandelic acid (from almonds). These work by loosening the glue-like bonds between the cells to reveal brighter and healthier skin underneath. They are effective at treating hyperpigmentation, fine lines, wrinkles and skin texture. Some AHAs can be quite plumping and moisturizing on the skin, so are ideal for anyone with more dry and sensitive skin. AHAs do increase photosensitivity to the sun, so it’s best to use them at night and always wear SPF in the morning!

BHA is an oil-soluble acid more commonly known as Salicylic acid. It is widely used to treat acne and breakouts. BHAs penetrate deeper into the pores to get rid of the gunk, dirt, oil and debris stuck inside, to give you clearer skin and reduce the appearance of pores. It also has some anti-inflammatory and antimicrobial properties to help calm irritated and inflamed skin. If you often get blackheads, acne or clogged pores BHA is going to be your best friend! It can be a little drying, so it’s better suited for those with oily and combination skin.

PHAs are a ‘newer generation’ of exfoliating acids, that work similarly to AHAs but are more gentle on the skin and don’t increase sensitivity to the sun. Gluconolactone and Lactobionic acid are the two PHAs found in skincare products. They have a larger molecular size, hence do not penetrate as deeply into the skin. They have been shown to be an effective anti-ageing ingredient, improving skin elasticity and reducing collagen breakdown in the skin. PHAs are ideal for anyone with very sensitive skin or anyone looking for a gentle, beginner-friendly exfoliant.

Now that you understand what chemical exfoliation is, you must be wondering how to find the right product for your skin? There are a few things to keep in mind. Product pH is an important factor to consider when picking a chemical exfoliant. At a very high pH it won’t penetrate the skin enough to work effectively; at a very low pH, it could be irritating and cause burns / post-inflammatory hyperpigmentation, especially on darker skin. It’s also important to look at the concentration of the acid in the product. As a general rule of thumb

AHAs: pH less than 4, concentration of 4-10%

BHAs: pH less than 3.5, concentration of 1-2%

Be careful when using chemical exfoliants! It’s easy to become impatient for results and over-exfoliate, which can result in a damaged skin barrier. Always start slowly, using it once a week and build it up to using every alternate day. Everyone’s skin is different, so be mindful of what your skin is telling you and only give it what it needs. Read the labels and follow the instructions carefully. And most importantly, always wear an SPF 30, with broad-spectrum UVA + UVB  protection in the morning! 

AHA / PHA products available in India 

  • Pixi – Glow Tonic
  • Isntree – 8% AHA Essence
  • Sheths – Gulab and Glycolic Toner
  • Cosrx – AHA Whitehead Power Liquid
  • Feel Raw Botanicals – PHA Toner
  • Paula’s Choice – Skin Perfecting 8% AHA Gel
  • Earth Rhythm – 10% Mandelic + Hyaluronic Acid Renewal Serum 

BHA Products Available in India

  • Paula’s Choice – Skin Perfecting 2% BHA Liquid Exfoliant
  • Cosrx – BHA Power Liquid
  • Cosrx – Salicylic Acid Exfoliating Cleanser
  • Suganda – BHA Exfoliating Serum


That's all for today! If you enjoyed this piece, be sure to check out Ria's Instagram @rithink_skin for tons of more informative skincare content! 

Until next time, 
Stay Curious. Stay Freequal.

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