Salicylic Acid (also known as beta hydroxy acid or BHA) is a well-known ingredient for treating skin that struggles with acne and clogged pores. It exfoliates both the skin's surface and deep within the pores to help clear out buildup, control oil, and reduce inflammation.

Unlike AHAs (alpha hydroxy acids), salicylic acid is oil-soluble. This allows it to penetrate into pores which makes it especially effective for treating blackheads and preventing future breakouts.

Sulfur is a commonly occurring element on Earth (and our universe!). In cosmetics, it helps kill bacteria, reduces sebum, and provides exfoliation. This makes it an effective ingredient to reduce breakouts and fight acne.

As a ketayolytic agent, it breaks down the top layer of skin. This is a form of exfoliation and may help decrease acne and hyperpigmentation.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.