Your Cheat Sheet to Skincare Acids

Acids – some love them, some fear them and others just are not sure what to do with them. Regardless of your relationship with them, we are here to demystify acids and simplify your selection and inclusion process for healthier skin! 

Credit: Karolina Grabowska 

What are Acids? 

Acids are some of the most beneficial skincare ingredients readily available. Additionally, they come in many forms – from Alpha Hydroxy Acids (AHAs), Beta Hydroxy Acids (BHAs) to the increasingly popular Polyhydroxy Acids (PHAs) – to provide a whole host of different benefits for various needs. But despite their varying benefits, all acids act as exfoliators to the skin.   

AHAs vs BHAs vs PHAs – What’s the Difference? 

Alpha Hydroxy Acids (AHAs) 

AHAs work on the surface to break the bonds between the outer layer skin cells, removing dead skin cells and revealing new skin. They are water-soluble, making it harder for it to penetrate the skin. Additionally, they are hydrophilic (aka they attract water molecules). This helps the skin retain more water to feel bouncy and hydrated.  

AHAs also make your skin much more sun-sensitive – thus, if you are adding AHAs to your morning routine, SPF is a must. Typically, higher concentration AHAs are more powerful and penetrative.   

AHAs are great for:  

  • Treating mild acne  
  • Lighten post-inflammatory hyperpigmentation, acne marks, age spots and other skin discolourations  
  • Increase collagen and elastin production for reduced wrinkles and fine lines 

Beta Hydroxy Acids (BHAs) 

BHAs also exfoliate the topmost layer of skin, penetrate deeper to exfoliate excess oil within pores and breakdown deep-set congestion. They are oil-soluble, allowing it to penetrate deeper into the skin. Unlike AHAs, BHAs do not attract water molecules. This can result in a drying effect for non-oily skin types. On top of that, BHAs do not make the skin more sun-sensitive, but SPF is still a non-negotiable in your morning skincare routine. Lastly, contrary to AHAs, a higher concentration of BHAs does not mean better results. In fact, BHAs are most effective at low concentrations of 2%-4%  

BHAs are great for:  

  • Soothing inflammation and its anti-bacterial properties  
  • Treating moderate to severe acne  
  • Lighten post-inflammatory hyperpigmentation, acne marks, age spots and other skin discolourations 

Polyhydroxy Acids (PHAs) 

Lastly, PHAs. PHAs are made of several hydroxyl groups, providing them with unique properties that differentiate them from AHAs and BHAs. PHAs are also the gentler alternatives to AHAs. Their larger molecule size allows them to stay on the surface layers of skin to exfoliate dead skin cells. They also share AHA’s hydrophilic properties – allowing them to help retain more water in the skin. Their gentler nature also allows them to be a friendlier alternative for dry or sensitive skin types.   

PHAs are great for:  

  • Exfoliating dry or sensitive skin types  
  • Soothing inflammation and has anti-oxidant properties  
  • Combatting glycation – a process that weakens collagen and elastin in your skin  

Overall, acids are great tools to fight acne, wrinkles, pigmentation spots, scarring and uneven skin tones. 

Credit: Karolina Grabowska 

Dos & Don’t of Using Acids 

Do: Use in Toners, Serums or Moisturisers 

Acids tend to work best when left on the skin for long periods. Thus, the most effective forms of acids are toners, serums or moisturisers. This is not to say that cleansers containing acids are ineffective, but they have less time to work their magic on your skin if they are washed off in under a minute.   

Don’t: Use Too Many or Too Strong Acids 

Although most AHAs work best at higher concentrations, it does not mean you should start stocking up on the highest concentrations of acids. It is important to remember that all acids are exfoliators. If you experience dull, lacklustre skin, using a wide variety of concentrated acids may sound ideal, but over-exfoliating can cause skin care problems (burns, dryness, acne and sensitivity)   

Instead, start small. Incorporate 1 to 2 acids at lower concentrations gradually in your skincare routine and allow your skin time to grow a tolerance. 

Do: Pair Acids with SPF 

AHAs and PHAs will cause your skin to become sun-sensitive. Thus, SPF is a non-negotiable. Even though BHAs do not cause sun-sensitivity, building the routine of using SPF daily protects your skin from much more. 

Do: Pair Correctly 

Skincare is like chemistry – curating and creating special regimes for healthy skin. However, not all chemicals are meant to be together. Here are the most commonly mismatched pairs. 

AHAs/BHAs/PHAs + Retinoids 

With Retinoids being a powerful active ingredient that encourages skin renewal, adding a chemical exfoliant can cause skin irritation and sensitivity. Furthermore, pairing AHAs/PHAs with Retinoids can cause the Retinoid to oxidise. This makes it less effective. 

BHAs + Benzoyl Peroxide 

Benzoyl Peroxide and Salicylic Acid (a BHA) are highly loved ingredients amongst those who suffer from acne. However, when used together, it can result in additional skincare problems. Both Benzoyl Peroxide and Salicylic Acid exfoliate the skin and help remove excess oil within the pores. This will cause the skin’s pH levels to be out of balance (not sure what skin pH is? Click here and find out!) The imbalance paired with over-exfoliation will result in redness, irritation, sensitivity and more.   

AHAs + Vitamin C 

Vitamin C is very pH sensitive. This means that any drastic changes in its pH would affect its efficacy. With AHAs typically being used at higher concentrations, it can alter the pH level of Vitamin C. Furthermore, both Vitamin C and AHAs work to increase cell renewal rate and exfoliate. Thus, it may cause the skin to become irritated and sensitive.   

Acid Glossary:  

With the number of acids readily available, here’s a quick summary on the most common types and their benefits.  


Citric Acid: derived from citrus fruits, it is often used alongside other acids to provide an optimal environment for effectiveness. It is also used for its antioxidant properties.  

Glycolic Acid: derived from sugar and it has one of the smallest molecules in AHAs found in skincare. This allows it to penetrate deep that other AHAs and thus, makes it one of the strongest AHAs. Therefore, it is best to use a lower percentage initially.  

Lactic Acid: derived from dairy, it is a form of AHA that should be avoided by those with milk allergies. Its molecule size is larger than Glycolic Acid, making it a gentler alternative for most people.   

Malic Acid: most commonly derived synthetically, Malic Acid molecules are larger than both Glycolic Acid and Lactic Acid. This makes its penetration slower. Malic Acid is also a fantastic supplementary AHA alongside Glycolic or Lactic Acids at low concentrations.  

Mandelic Acid: derived from almonds, it is a form of AHA that should be avoided by those with nut allergies. With larger molecules that Lactic Acid, it makes Mandelic Acid a great AHA for sensitive skin.   

Tartaric Acid: most commonly derived synthetically, Tartaric Acid’s molecule is almost double of Glycolic Acid’s. This makes it most efficient at exfoliating the topmost layer of the skin.   


Salicylic Acid: Salicylic Acid is the most commonly used BHA in skincare. Derived from many different sources, Salicylic Acid penetrates deeper than AHAs to breakdown oil buildup and congestion in pores.  


Lactobionic Acid: derived from dairy, it should be avoided by those with milk allergies. With molecule sizes greater than Glycolic Acid, it makes Lactobionic Acid less able to penetrate the skin. This makes it a gentler alternative for sensitive skin.   

Gluconolactone: derived from Gluconic Acid (a naturally occurring acid in mammals and corn), it is often used to support other ingredients – much like Citric Acid. 

That’s all! Ready to give acids a try?  

Make our Glycolic Toner a part of your nightly routine! With low yet effective percentages of Glycolic Acid and Lactic Acid paired with the deeply hydrating Sodium Hyaluronate, this toner will gently brighten your skin why hydrating it thoroughly. 


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