Don’t waste that expensive serum!

Ever looked deep into a sheet mask packet? If no, you’re missing out on a bucket of goodness. Most brands pack in extra serum or essence to make sure your mask is thoroughly soaked and hydrated by the time you open it. And yep — all that leftover serum is totally useable!

Plus, most sheet mask direction only recommend leaving it on for 15 to 20 minutes. Leaving it on until it’s dried could potentially cause reverse osmosis, where the mask starts to pull moisture from your skin. So, don’t let that youth juice go to waste!

  • Apply the rest down your neck and chest. Pour a bit of serum onto your palms and make sure you get your neck and chest. Most people miss these areas when tackling their skin care routine.
  • Use it to refresh your mask or spot treat. If your mask starts to dry out but you want to keep on moisturizing, lift up your mask and slide some serum under there. Then close your eyes and hydrate away! You can also cut out a smaller piece and leave it where your skin needs it.
  • Use it as a serum. Let your face dry off and then reapply serum to get a reboot of glow. Then, seal the serum in with a layer of moisturizer.
  • Make a twin mask. If there’s a lot of excess serum, soak a dry cotton sheet mask in it and give it to a friend so you can mask together.
  • If the mask is still soaked, use it as body moisturizer. Peel the mask off and, like a washcloth, rub in circles over your body. Concentrate on areas that feel parched.
Pro tipThere may be more serum than you know what to do with, but avoid storing the serum for later use.

Sheet masks are designed to be used immediately after opening, so the preservative system probably won’t last under nonsterile conditions. You don’t want to be putting bacteria and mold on your skin — that can potentially lead to infection.

Michelle explains the science behind beauty products at Lab Muffin Beauty Science. She has a PhD in synthetic medicinal chemistry. You can follow her for science-based beauty tips on Instagram and Facebook.