But then there are those tricky serums.

They answered all our burning questions, including when and how serums should be used.

Keep reading to learn more.

A trio of serums standing on a linen cloth

Liz de Sousa / Byrdie

Meet the Experts

What Are Face Serums?

But Bosley recommends focusing on the active ingredients and not so much on what’s popular.

Both experts agree thatthe general rule of utility is to go from the thinnest to the thickest product.

Serums are typically applied after you wash your face but before heavier products like moisturizers and sun protectants.

Do You Still Need Moisturizer and Sunscreen?

The short answer is yes.

“A little bit goes a long way, so stick with just a few drops.”

He suggests applying a thin layerusually a few dropsspread evenly over the desired area.

Drop the serums in your hands first, or hover the applicator over the skin without touching it.

And, when in doubt, always seek the expertise of a dermatologist.