Does Your Serum Look A Bit Off? Here Are Signs Your Vitamin C Product is Expired

Vitamin C is one of your skin’s best friends, but it can be a finicky ingredient.

Writing love letters to vitamin C is one of our favorite pastimes around here. This multitasking, antioxidant-rich ingredient protects your skin from free radical damage and can help create a brighter, more even complexion. There’s one catch though: she’s a feisty one.

As amazing as vitamin C is, it’s considered a “volatile” ingredient that tends to expire more quickly compared to other skin care ingredients.

“Vitamin C is an antioxidant which slows down our cellular oxidative aging,” says Dr. Ava Shamban, a board-certified dermatologist based in Beverly Hills, Calif. “You may notice it is stored in a dark glass bottle or with an airtight pump. This [helps prevent] oxidation or the loss of hydrogen atoms.”

Even though vitamin C products are typically packaged well, they still tend to have shorter shelf lives and are prone to souring. Once your vitamin C has gone bad, it’s best to throw it away. Dr. Shamban says that at that point it can no longer go up against the free radicals responsible for causing oxidative damage to our skin.

Having a hard time telling when your vitamin C is expired and has lost its potency? Check out our three top signs below!

Signs It’s Time to Toss Your Vitamin C Product

There are three key signs of vitamin C expiration to be on the lookout for.

New Color

A change in color is the biggest red flag—and usually the first sign—that your vitamin C is expired.

“Depending on the serum texture and type, it may start to turn a shade of yellow, brown, or even orange,” says Dr. Shamban. “Basically, if it is any shade other than what it looked like when you first bought it, it has already turned bad.”

Textural Change

Along with a change in color, you may notice that the texture of your product has shifted. Common signs include separation, loss of “form,” stickiness, thickness, graininess, or sometimes even thinning out.

Sour Smell

Each product has its own distinct scent—even if there’s no fragrance added. Dr. Shamban says that if you start to notice a more “sour” smell that’s unusual for the product, it’s probably gone bad. Usually, this is accompanied by a change in color and texture so it should be obvious.

It goes without saying that different concentrations and formulations may have some variations on the above, but any time a product has shifted in appearance and smell that’s a solid sign it’s time to toss it in the garbage can. If you have a hard time remembering what the product should look like, take a picture of the brand-new product in the bottle and/or dispensed onto your fingers and refer to it as needed.

Bottom Line :

Don’t forget to use your favorite vitamin C product every day! When stored sealed tightly, stored in a cool place, and used consistently, you’ll use it all up before it bumps up against that expiration date.

+ What’s your favorite vitamin C serum?