Here's How To Tell If Your Vitamin C Serum Has Gone Bad

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Vitamin C serum is beneficial for many different reasons. It's an antioxidant, making it excellent at protecting your skin from toxins. In serum form, vitamin C can slow the signs of aging, improve the appearance of wrinkles, even out skin tone, and treat acne. Studies show that applying it topically is effective when your product has a strength of 10% to 20% and has a pH lower than 3.5, according to Harvard Health Publishing. To know if your vitamin C serum fits these criteria, you can look at the ingredient list on the brand's website.


Adding this serum to your skincare routine is easy. Once you've washed your face with a mild cleanser, apply the serum. Then follow up with a moisturizer and an SPF for your daytime routine. When you apply vitamin C, it may tingle, but you don't need to be concerned unless you feel a lot of irritation. To prevent this, start by only using the serum every other day. You should start seeing improvement in your complexion after three months of consistent use.

Color, smell, and expiration date

There are three ways to know if your vitamin C serum has expired. The Go-To Guide explains that vitamin C is volatile, so it won't last as long as your other skincare products. It must be stored in the correct bottle and location, or it will expire quickly. By paying attention to the color and smell of your serum when you first purchase it, you'll know when it has gone bad. It usually looks clear or slightly yellow. Once it turns to a dark yellow or orange, your serum has oxidized and expired. To determine if it's okay to use based on scent, you need to know what it smelled like when you first opened the package. This is because different brands can have different smells. You should pay attention to whether the scent has changed, not if it smells rotten.


The simplest way to decide if your vitamin C serum is expired is by the expiration date. On the bottle, there should be a date printed. Write that expiration date in your calendar so you won't forget it. If the brand you own doesn't have a date on the bottle, you can approximate the month and use the other factors to know when to stop using it. Vichy Laboratories explains that vitamin C serum lasts about three to six months.

The best way to store your serum

How you store your vitamin C serum can help it last for as long as possible. You won't have to throw away products that you could still use prematurely. The type of bottle it's in is a crucial factor. Since the manufacturer controls this, pay attention to the color of the bottle when purchasing your serum. It should be in a dark-colored bottle, never clear glass, according to The Klog. Vitamin C needs this because it is sensitive to light and heat. Without protection, it will oxidize faster and degrade.


Storing your serum in the fridge is a great way to protect it from light and heat. It will keep your vitamin C fresher and more potent for longer. You want the active ingredient to stay powerful so that you can get all the benefits from it, explains Teami. As your serum breaks down and expires, it won't work as well, either.