A face mask, or facial mask, consists of clay, gel, enzymes, charcoal, or a mix of other ingredients. You apply the mask to your face using your fingertips or a brush.

Sheet face masks are a variation on the traditional facial mask. These are made of a fabric soaked in a nutrient- or vitamin-rich serum or essence.

Depending on your skin concern, you want to choose a face mask that has specific ingredients for targeting dryness, dullness, or acne, for example.

Some masks are specifically designed as overnight masks (also called sleeping packs), and they’re generally safe to wear while sleeping.

Other masks may be too drying to leave on all night, but they could help as a spot treatment if you have a pimple.

Some gentle masks, either homemade or store-bought, can be safe to use overnight, though they may get your pillowcase dirty or cause dryness.

Sleeping with a face mask applied, especially one intended to be used overnight, has benefits for your skin.

Overnight face masks are essentially the same as thick nighttime moisturizers, but they have many active ingredients all working together at once.

Active ingredients like salicylic, glycolic, and hyaluronic acids target skin concerns, while other ingredients like water make up the mask’s formula or aid the active ingredients’ function.

The benefits of sleeping in a mask include the following:

  • They can be especially hydrating. The ingredients have longer to absorb into the skin, which can be especially helpful for older people because skin loses moisture with age.
  • Studies show that cells replicate and renew overnight, and a face mask helps these cells do this effectively.
  • Some overnight masks have a sealant ingredient that locks in moisture and also helps keep dirt and other pollutants from getting into pores.
  • Many nighttime masks contain soothing minerals, vitamins, and other skin-boosting ingredients.

If a mask isn’t specifically designed for overnight use, it’s still generally considered safe to sleep in one. There are certain things you should be aware of, however:

  • If you’re using other skin care products that contain retinol or acids, don’t sleep in a mask that has these same ingredients. Doing so could be irritating to your skin.
  • Certain ingredients like clay or activated charcoal may be too drying to use overnight. Avoid sleeping in masks containing such ingredients unless you have very oily skin.
  • DIY masks or masks that don’t harden may be too runny to sleep in, possibly ruining your pillowcase and sheets.
  • Avoid products with alcohol, which can be drying and damaging to your skin.

Most store-bought masks will have directions for use. Before you use one, test a little on your skin first to make sure it doesn’t cause an allergic reaction.

Generally, you apply a mask to clean, dry skin. Wait for it to harden or set before going to sleep to avoid ruining your bed linens.

If the mask is runny and won’t harden, consider putting a towel over your pillow.

Wash off the mask thoroughly in the morning, unless it has fully absorbed into your skin (as some hydrating masks do).

Nutrients in overnight masks seep into the skin all night. This can make for pronounced hydration that is helpful for dry, dull skin. Hydrated skin may look less wrinkled and brighter than normal.

If you want to moisturize your skin, look for a facial mask with collagen peptides (an ingredient that studies show is also effective for skin when taken orally), ceramides, or other hydrating ingredients.

Masks with acids like alpha hydroxy acids or beta hydroxy acids may help slow signs of aging.

You can buy an overnight mask in most drugstores, online, or in specialized makeup stores.

An overnight face mask is made of a blend of beneficial ingredients. You can easily purchase one or try make your own.

Some masks, called sleeping masks or packs, are specifically designed for overnight use. These are generally safe, though you should always test them on your skin first to avoid possible allergic reactions.

Avoid masks that contain drying ingredients like alcohol, and if the mask isn’t designed for overnight use, make sure the ingredients are gentle.