Explained

Glycolic acid is the benchmark exfoliant – the one every other acid gets compared to. It's also the one most likely to be overdone. Here's how to get the results...

AHA is one of those acronyms that appears on half the products in a bathroom without ever being properly explained. Here's what alpha hydroxy acids are, how the main ones...

Witch hazel has been in bathroom cabinets for well over a century, which makes it one of the few skincare ingredients your grandmother and your dermatologist might both have an...

Azelaic acid doesn't get the attention retinol or vitamin C do, but it's quietly one of the most useful actives on the shelf – particularly for anyone whose skin reacts...

Salicylic acid is the ingredient most people reach for when their skin looks congested – and the one most often used incorrectly, usually by applying too much, too often, to...

Retinol has been in cosmetic skincare since the 1980s, which makes it the most studied ingredient on most people's shelves. It also has a reputation for being difficult – and...