Skincare Product Expiration 101 - Understanding the Shelf Life of Your Favorite Skincare Products

If you're a skincare hoarder, you'll be disappointed to find out that you might need to toss some of those half-used serums and creams. Why? Because once you open up a product, the clock starts ticking toward both a best if used by date (when the product is effective) and an expiration date (when the product is unsafe). These terms mean different things, and have different results for your skin, but it can be confusing to understand the difference. We’ll dive into how to know when it’s time to clean out your products and recycle the bottles.

P.S. Before you throw away your empties, learn how to recycle beauty products, so you reduce pollution and limit your impact on the environment.

Can You Use Skincare Products After They Expire– i.e. when products have become unsafe?

Using expired skincare products is not a good idea. Outside of no longer being effective, expired skincare could grow microbial bacteria and be more likely to give you reactions such as redness, sensitivities and irritation. 

How Do I Know When My Skincare Products Expire?

Some brands opt to show a PAO (period after opening) date on packaging, but if your product doesn't have one, the rule of thumb is to throw away anything that has significant changes in color or scent, has thickened, thinned, or clumped. Observe if your skincare products have another color or if they feel or smell different than when you first started using them. These are all signs that your skincare product has gone bad. 

Skincare Shelf Life Guide - When Do Your Favorite Skincare Ingredients Expire After Being Opened?

Shelf life is the period before the expiration date and describes how long a product can last without growing bacteria or becoming potentially harmful having never been opened.

Generally, skincare products last from one to three years if not opened. The PAO (period after opening) label on the product should inform you when the expiration date is after you’ve popped open the lid. 

If there’s no PAO listed, you should use most products within six months to one year, as they have a much higher chance of developing bacteria after then. "Exposure to moisture, such as in a bathroom, may make it easier for bacteria and fungi to grow," FDA notes.^[1] 

Best if Used By Date– i.e. when products are still effective

It would be easy to simply say that you should toss beauty products after they have expired. Unfortunately, that does not account for the product's efficacy which diminishes far before the expiration date. Once opened, cosmetics often start to lose their active ingredient potency. This is caused by the active ingredients degrading once exposed to air and light, and means the product will not provide the same benefits as it would when it was first opened.  

A product’s best if used by date should inform you of when a product may become ineffective, however, the majority of skincare brands  do not overtly add this date to their labels. 

According to our independent study on the top 25-selling clinical skincare products, active ingredients degraded by 40% within eight weeks on average. Conclusion? The fresher the ingredients in your skincare, the better the benefits.

When Does Retinol Become Ineffective?

Retinol’s best if used by date is within six months. Retinol's potency declines up to 80% after six months at 77°F and up to 100% when stored at 104°F and is more sensitive to light than heat.^[2] Many don't know how to tell if retinol is fully expired because there aren't clear signs since retinol doesn't have a scent nor changes its color. 

When Does Vitamin C Become Ineffective?

Vitamin C best if used by date is within approximately two months after opening it. As an antioxidant prone to degradation when in contact with air and light, vitamin C loses potency every time you use it. Once oxidized, vitamin C becomes totally ineffective, so you will definitely want to use your product within three months of purchase.

What happens if I use vitamin C serum that’s past its effective period?

Using vitamin C serum that’s degraded will most likely do nothing irritating to your skin, but iyou won't receive its protective, brightening, or collagen-boosting benefits. 

When Does CoQ10 Become Ineffective?

Generally, CoQ10’s best if used by date is within six months. CoQ10 is an antioxidant, so it degrades quickly, especially if kept in light or sitting in a steamy bathroom. For the record, coenzyme Q10 has a yellow/orange color; if it turns brown, you know your serum is probably off and ineffective. 

Other Common Questions About Skincare Product Expiration

There's a lot of confusion around using expired skincare products, and for fair reasons. Everybody wants the best from their skincare routine. How long should you keep serums? Read on.

Do skin care products expire if not opened?

Unopened skincare products can often last up to three years since the chances of bacteria getting into the formula are nearly zero. Most cosmetic manufacturers perform stability tests to ensure the products last two-three years if unopened. But this also can be influenced by temperature or if excess sunlight reaches the container. The expiration date on the product will inform you how long it should last if unopened. If no expiration date is listed, look for a PAO (period after opening) mark.

Can I use expired moisturizer?

There’s not necessarily anything harmful about an expired moisturizer, but nothing good either. If the moisturizer dispenses via an airless pump, chances are it hasn’t gone bad. But if it's the kind of moisturizer that has an open jar, it's more likely to harbor bacteria. This bacteria can cause irritation or blemishes. 

Does hyaluronic acid expire?

Hyaluronic acid expires like any other skincare ingredient. Usually, hyaluronic acid formulations are water-based, and "water-based products, including liquids, creams, and lotions, are more prone to spoilage from bacterial growth if the preservative system isn't strong enough or if the product is constantly coming into contact with the user," cosmetic chemist Jim Hammer reveals.^[3]

If adequately stored, hyaluronic acid lasts for about one year. You know your hyaluronic acid serum is off if you notice the product looks different than when you first used it, such as if it has a change in texture, color, or has separated.

Replenish Your Skincare Products with Fresh Ingredients by Exponent Beauty

From the moment you open a product, your skincare products are consistently losing their efficacy. Although degraded actives might not be the end of the world, having an ineffective routine is not going to provide you with any benefits. Spoiled ingredients are less potent, so using fresh actives might be the game-changer your routine needs.

The good news is that the adage, "all good things come to an end" doesn't apply to Exponent products. Unlike traditional water-based skincare formulas that start degrading the moment they're manufactured, our active powders keep their potency until the instant you activate them with our Quadruple Hydration Hyaluronic Serum. Check out our active powders filled with tried-and-true ingredients for results raised to your level and skincare that doesn't become ineffective before you know it.