Ever go to take another bite of an apple and notice how it’s started to brown just a few minutes after the first bite? Or how about the annoying fact that avocados will turn brownish-black in what feels like just seconds after you’ve sliced them? That’s all due to a fun little chemical reaction called oxidation, and it doesn’t only apply to food—it can happen to your foundation, too.

Many factors may cause your foundation to oxidize, from your skin’s texture to the foundation formula. Luckily, there are things you can do to prevent this. Read on for tips to prevent your foundation from oxidizing from board-certified dermatologist Joshua Zeichner, MD, and celebrity makeup artist Jamie Greenberg.

Meet the Expert

• Joshua Zeichner, MD, is the Director of Cosmetic and Clinical Research in Dermatology at Mount Sinai Hospital in New York City.
• Jamie Greenberg is a celebrity makeup artist and Marshalls Beauty Expert.

01
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Make Sure Your Face Is Clean

This may seem like a no-brainer, but clean skin is healthy skin, and healthy skin is happy skin. Don’t even think about applying foundation on an unwashed face (or worse—over yesterday’s makeup). That’s just asking for mismatched tones and a host of other problems. Be sure to cleanse your face each morning before applying any product or makeup.

02
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Don’t Skip Toner

Swiping on a facial toner will help balance your skin’s pH while absorbing excess oil your cleanser may have left behind. Zeichner explains that foundation oxidation “occurs more commonly in people who have oily skin,” so eliminating excess oil as much as you can before application is an important first step to preserve the integrity of the color.

03
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Opt for Water-Based Skincare Formulas

Greenberg recommends opting for water-based or more naturally composed skincare formulas that are light on the oil while still being effective and hydrating. The more you can avoid oil-based products, the less you’ll risk having your foundation change things up on you.

04
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Apply a Primer

Zeichner says that applying a primer to your skin pre-foundation may help absorb excess oil while creating a neutralized base layer for your foundation to bind to.

05
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Choose the Right Foundation

Greenberg explains that not all foundations oxidize, and it’s a matter of trial and error to find the right one for you and your skin in the first place. “If you fall in love with a brand that oxidizes, you’d want to get that foundation in a shade lighter than you would normally wear,” advises Greenberg. This will help balance the color change and make sure you’re well-matched.

06
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Use an Applicator, Not Your Fingers

Because the oils (and other contaminants) from your hands can cause reactions within your foundation bottle, you should use an applicator sponge or foundation brush and never your fingers or hands. Doing so will not only result in a smoother and more flawless application but, Zeichner says, will also preserve the integrity of your foundation and prevent oxidation.

07
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Blot Away Excess Oil

Blotting excess oil from your face is important before and after foundation application. If your face accumulates oils or starts to look greasy throughout the day, carry blotting papers. These will help absorb the oil as opposed to letting it sit on the skin’s surface, which may affect the overall appearance and tone of your foundation.

08
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Use a Setting Spray or Powder

Zeichner says spritzing on a setting spray or powder will help minimize oxidation, too: “It helps absorb excess oil to lower the risk of reaction with the pigment in the makeup,” he tells us.

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Be Mindful of Shelf Life

Zeichner notes that the average shelf life of a foundation is around 12-18 months. So, if you don’t use it daily, be mindful of how long it’s been sitting on your shelf. If you use your foundation after the expiration date, it may appear dry and clumpy in texture and may also be more likely to oxidize due to oils separating and rising to the top.

10
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Clean Your Brushes

Take care of your trusty makeup brushes, and they’ll take care of you. Keeping your brushes clean and sanitary ensures they’re performing at their best and maintaining the integrity of your products. Excess oils left behind on brushes can lead to your foundation oxidizing, so prevent it by cleansing your brushes and sponges weekly or biweekly.

FAQ

• How do I know if my foundation will oxidize?
  

  Foundations that are made with oil or oil-based are more likely to cause your foundation to oxidize. Look for foundations that are water-based formulations, as these are less likely to oxidize.

• What causes foundation to oxidize?
  

  Most of the time, foundation oxidizes because your makeup combines with the oils in your skin, causing your foundation to oxidize or deepen in color.

• How can I stop my foundation from oxidizing?
  

  If you find your brand new foundation is oxidizing, you’ll want to try and use oil-free products and set your face with powder to start. If your foundation is looking a bit old and the oil and color have started to separate, it’s best to toss it out.