This post may contain affiliate links. I may receive commissions for purchases made through links in this post. I will never recommend any products that I don't believe in. Please read my Disclosure for more info.

Acids are one of the tried, tested, and proven skin care ingredients that offer a substantial number of benefits to the skin. But, what’s with all the different types; alpha hydroxy, beta hydroxy, glycolic, lactic, salicylic, malic! With so many scientific-sounding names, what’s a girl to do?

Here’s the low down, the down low, and everything in between

Glycolic acid is an alpha hydroxy acid that is derived from sugar (yes, sugar actually has a healthy side.) It consists of the smallest molecule giving it the ability to penetrate deeper into the skin than the other acids.

The smaller the molecule the easier it gets into the skin, and because glycolic acid can boast having the smallest molecules it produces the most dramatic results.

It’s a really powerful anti-aging acid as it has been shown to regenerate collagen, thicken the dermis and epidermis, and even out skin tone.

One little caveat, however, with this sweet anti-aging powerhouse is that because of its ability to penetrate as deeply as it does, it has the greatest potential to irritate the skin. So, go in slowly.

Salicylic acid is a beta hydroxy acid which does a great job treating acne. It has the ability to penetrate into the skin and unclog pores helping to promote a clearer complexion. Salicylic acid is a more targeted acid than AHA’s due to the fact that it really dives into the pores clearing them out. Even if it’s only on the skin for a minute it will get the job done.

Lactic acid is derived from sour milk and happens to be the second smallest molecule just after glycolic acid. It’s a bit more gentle than glycolic and actually draws moisture into the skin as it works to remove dead skin cells.

Fruit acids including citric (from lemons and grapefruits) and malic (from apples) have larger molecules and work on the uppermost layer of the skin. They help to uniformly exfoliate the surface of the skin but won’t have the same dramatic results as glycolic acid.

Trichloroacetic acid, also known as TCA, is a more serious acid contender. It’s used by doctors for very intense peels that cause extreme peeling. This acid should only be used in a doctor’s office and should be avoided by those with darker skin tones due to the risk of hyperpigmentation.

So there you have it; all tucked nice and neat into a nutshell. Acids are a great addition to any skincare routine but knowledge is power and it helps to know the differences between the varieties of acids, what they are used for, and which one is best for your particular skin concerns.