Why Does Makeup Oxidize?

… and how to prevent it from happening.

Have you ever believed you found the perfect foundation shade just to notice that after letting it sit on your skin for ten minutes, it looks way too warm-toned or dark?  I hate to break it to you, but your foundation, most likely, just oxidized.  

Oxidation is frustrating, deceiving, and a disheartening waste of money.  How are you ever supposed to make up your mind on a true match if your foundation can’t find a tone to settle on itself?  I mean, what even is oxidation anyways?

What is Oxidation?

Just like how metal oxidizes to a rusty red, how open fruit oxidizes to a light brown, and how the Statue of Liberty oxidized to mint green, your foundation can oxidize too.  By dictionary definition, oxidation is the combination of a substance with oxygen.

When your “perfect” foundation first is applied to your skin, it might look like just that -- a perfect match.  But as it sits on your face instead of in a sealed bottle, it comes in contact with the air.  Oxidation can take anywhere from 1 hour to a whole day to occur, depending on a couple different factors.

Why Makes Oxidation Happen?


1.Oily Skin

Chances are that the natural oils in your skin are causing a reaction with the pigments in your foundation.  This can pull out warm and orangey hues, especially for those with a peachy or flushed complexion.   

2. Old Foundation

If your foundation is suddenly the wrong shade and it’s been open for anywhere between 6 to 12 months, it most likely oxidized inside of the bottle.  This can happen when the foundation isn't stored in an airtight or light resistant container.  Throw it out and pick yourself up a new one, girl!


How To Prevent Oxidation

  • Before applying your makeup, always start with clean skin.  This will help eliminate any oils on the skin's surface.  
  • Use a lightweight, water-based, daytime moisturizer to ensure that the oils in your existing moisturizer aren't causing oxidation
  • Apply a mattifying primer to create a barrier between your skin and your foundation
  • Throw out any foundation that has been open for over a year
  • Store your foundation in a dark spot
  • Stay away from foundations with titanium dioxide, zinc oxide, and iron oxide high on the ingredient list

For more help on finding a perfect foundation match for your skin, read our article here.   You can also find more information on makeup expiration here!  



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