Learning the different types of acids in skincare - AHA, BHA


Ever get overwhelmed with skincare - what to use, what ingredients are best, when to put it on your skin?  With so many amazing products out there right now in the clean beauty world, figuring out what is best for you and your skin can be a tad much!

Right now the ingredient that is on our MUST list is acids, a true staple in our routine because they help to improve skin by inducing cellular turnover. Acids work by lifting off the top layer of skin (the buildup of dead cells on the skin’s surface) to allow new ones to grow below, thus improving your skin's tone, texture and overall appearance.  Depending on the molecular size and strength of the acid you are using, they target different skincare concerns, so it's of utmost importance to know what you are applying to your skin and following instructions so you don't damage your skin and skin's barrier.

So, you ask, where do I start? Step one is deciphering the different types of acids found in beauty products: hyaluronic, glycolic, lactic, salicylic and more. How are they different and why does it matter?

Acids Benefits
lactic, citric, malic, and tartaric acids AHAs that act as exfoliants, they also work to lighten uneven pigmentation and smooth out skin texture. Lactic acid is the best researched AHA after glycolic acid, and is notable for being gentler, more hydrating, and more effectiveTrusted Source at treating sun damaged skin.
ferulic acid antioxidant ingredient that’s most commonly used in conjunction with vitamins C and E in serums. This powerful antioxidant trio is well known for its ability to protect the skin from the damaging free radicals generated by UV radiation.
lipoic acid antioxidant ingredient with anti-aging benefits. Its effects are quite modest so its popularity is waning.
trichloroacetic acid (TCA) used in peels, and is especially useful for flattening out scars in the TCA cross techniqueTrusted Source. It’s very potent and should be used by professionals only.
alguronic acid byproduct of biodiesel production. It’s reported to have anti-aging effects, but these are yet to be supported by peer-reviewed research.

So which acid should you use? 

Choosing which acid to use is the hard part. The easiest way to go about it, is by knowing what problem you want to treat.

Best for… Acid
acne-prone skin azaleic acid, salicylic acid, glycolic acid, lactic acid, mandelic acid
mature skin glycolic acid, lactic acid, ascorbic acid, ferulic acid
fading pigmentation kojic acid, azelaic acid, glycolic acid, lactic acid, linoleic acid, ascorbic acid, ferulic acid

Pro-tip: The higher the concentration, the more likely the acid will irritate the skin. Always patch test and start with a lower concentration before moving up.

How to incorporate acids into your routine

1. Slow and steady wins the race.

As a rule of thumb, test the formula on your inner arm and wait for 24 hours to see how your skin looks and feels after. This should really be a rule of thumb for any new skincare product you are adding to your routine, to make sure you don't have any adverse effects. If everything is okay, slowly introduce the product into your routine, building up from twice a week to the frequency the product was designed for.

2. Don’t forget your SPF!

Apply your SPF 30 plus, broad spectrum (UVA plus UVB) sunscreen every two hours. As a rule, It is important to protect your skin adequately after using any exfoliating skincare with AHA/BHAs so it does not get burnt or become more prone to pigmentation.

3. Avoid if your skin is flaking, inflamed, cracked. or you have any open wounds.

If your skin barrier is compromised, products that would typically be well-tolerated can cause further irritation and redness. Darker skin tones should also approach with caution as it can cause skin discoloration.