“Your best option is to use the vitamin C product within a three-month time period,” she says, noting that the average vitamin C serum lasts for three to four months before it expires. “You can also keep your product away from heat and light,” she says.
Notice any scent or texture changes
It is unlikely that an oxidised or expired vitamin C serum will cause harm to your skin, so don't stress if you're reading this and only just realising your serum may not be in its best shape.
Although your Vitamin C serum will lose its efficacy once oxidized, the product does not become harmful to the skin until it's expiration date, approximately one year after manufacturing. For best results, we recommend using your Vitamin C serum within 3 to 6 month of purchase, when it is fresh and most effective.
A classic telltale sign of expired or oxidised Vitamin C is a change in colour. If you've spied that your once clear or light yellow serum is now looking a little deeper, or has changed shades entirely, you can take this as a pretty clear indication that your product has oxidised.
5. Vitamin C Serum. How long it lasts: Wilson said vitamin C serums are typically good for up to a year once they've been opened, but “it varies on the type of vitamin C that's being used.” “If [your product] uses ascorbic acid, definitely [toss it after] a year.
How Can You Prevent Your Vitamin C Serum From Going Bad? “Your best option is to use the vitamin C product within a three-month time period,” she says, noting that the average vitamin C serum lasts for three to four months before it expires.
Unfortunately the manufactured date is not always written down. If you have an unopened (sealed) skin care product with an expired date on it and you wonder if you can still use it, the answer is that it depends on the product itself. Usually these products are additionally 1 to 3 years valid.
A pure and potent vitamin C serum will be clear. The moment you start to notice your serum tinging towards a translucent brown or orange shade, it's time to toss. This means the ascorbic acid (vitamin C) has oxidized, and no longer holds its antioxidant powers.
Discard your serum once it turns yellow or brown.
For most formulas, this usually happens after about 3 months at room temperature or 5 months with refrigeration, although the exact amount of time will vary between brands.
Turns out, it's pretty easy. “If your serum started out clear and now looks amber colored, it is time for a new bottle,” says Dr. Zeichner, noting that this yellow coloring indicates that it's begun to oxidize.
When in the vitamin C is in high concentration, the serum will have a yellowish color; but as it oxidizes, it will turn brown/orange. Cosmetic vitamin C preparations that have discolored should be discarded as they have already oxidized and cannot provide skin benefits.
You sure can. In fact, according to Daily Vanity, by and large, using expired skincare shouldn't be dangerous in any way. The only thing you might notice is that the product won't be as fresh or as vibrant as it might otherwise have been.
Specific products can vary, but in general, unopened skin care can last from one to three years. After opened, you should use a product as directed promptly, within one year. Always throw away a product if it seems discolored, develops a strange odor, or the consistency changes (if it becomes lumpy, runny, etc).
While recommended by most dermatologists, especially as we age, serums don't last as long as we would like them to, especially if they're opened. It's not that they necessarily go bad, it's that they lose the good stuff that makes us shell out the extra cash for them from the get-go.
“If it is past expiration, don't use it,” she says. Hyaluronic acid (HA) is another powerhouse ingredient that can be temperamental, Simon says. “It will gel up a formulation over time,” she explains. “If you notice small pills when you are applying on the skin, it is past its prime and time to toss.”
“Your vitamin C serum should be colorless or a light straw color; if it oxidizes, it becomes yellow or brown and is likely going to be less effective.” You can still use it if you want, but it probably won't do as much for your skin and, “very rarely, oxidized vitamin C products can even cause slight yellow ...
Vitamin C That Has Oxidized in the Bottle
(With L-ascorbic acid, this usually takes about three months after opening the bottle.) The reason it can stain your skin is because vitamin C degrades into erythrulose—the EXACT ingredient you'll find in many self-tanners!
Expired products may not only lack potency, but could also cause an adverse skin reaction. If you're unsure how old something is, the general rule is to toss anything that has significantly changed in color or odor, or separated, clumped, thickened or thinned, says cosmetic chemist Mort Westman.
Products will contain an unopened or shelf-life expiration date on the packaging. This date tells us when a product expires even if it remains unopened and unused. Manufacturers typically print the second expiration date on the product.
Look to the bottom of your packaging for a stamp with an expiration date. If you can't find one, look for a symbol with an open jar and a letter m to indicate how long your product will last after opening. For example, 12m means your product is good for 12 months after you first open it.
You can eat food after the sell-by date. For example, dairy products are good for 1 week after the sell-by date. Eggs are safe for 3 to 5 weeks after the sell-by date.
"Sometimes using a product that is expired can result in skin irritation along with bacterial infections. Most products have preservatives in them to keep fresher longer but over time, even preservatives lose their effectiveness," Sellers said.
"Some products may actually last longer and will still be effective for longer than that," he adds. But even if they're still effective and safe, expired skin-care products could give you other reasons to toss them. "They may develop an off color, may not smell as nice, and may not be as pleasant to use."
Many serums are yellow, but if your product takes on a brown or dark orange hue, it's time to toss because it's gone bad. If your serum starts out clear and turns yellow, that's also a sign it's oxidizing and will be less effective.