Everyone knows that nothing comes between a woman and her favorite make-up product—we all scrape and scrape until we get every last bit of color out of those plastic tubes! I know I’m not alone here when I say that I’ve held onto discontinued lipsticks that are the perfect color for me even if they are, really, REALLY old!

Though this urge to keep effective products can be tempting, they could be making you sick.

Hadley King, M.D., the dermatologist at SKINNEY MedSpa, explains to Women’s Health that, “All of the molecules in these products can break down into something else, and you can have a reaction to it.”

The doctor goes on to say that using old make-up puts you at a risk for contracting contact dermatitis, which is, ultimately, an inflammation of the skin.  Contact dermatitis can develop into redness, bumps, a rash, or even blisters and swelling of the skin, says King.

Yikes! It’s a bit frightening to think that the cosmetics we use to improve our appearances can also do some serious damage.

King furthers her point by explaining that we must also consider the reasons why we use our make-up in the first place. For example, many of us out there rely on cosmetics to get our necessary application of SPF, but with an expired cosmetic, the odds that the skin is protected from UV rays may be diminished.

Alright, are you hurriedly combing through your make-up drawer yet? Good! I’m happy that you are keeping your health in mind. If you aren’t too sure what products are expired, let me give you a tip!

Take a look at the side of the make-up bottle and locate the expiration symbol—it looks a bit like an open concealer pot!

There will be a number in the middle of this symbol with an ‘M’ followed after it. This number stands for the amount of months you can safely use this product from the date you opened it.

We all know that it can sometimes be difficult to remember the exact dates of purchase, but if you’re at all in doubt, the research definitely recommends that you chuck it!

Of course it can be heart wrenching to throw out an expensive product, but potential pain and medical bills are far worse.

It’s also important to point out that due to varying moisture in the air or improper storage techniques, make-up may end up turning before this date. If you notice a change in consistency, color, or smell, then it is time to let go of the product.

Since learning of the make-up expiration date symbol, I’ve gotten into the habit of writing in my own “throw out by” date on all of my cosmetics. It’s a great way to be certain that my favorite concealers and lipsticks are helping me, not hurting me!

Do you have any expired make-up horror stories? What’s your go-to beauty product?