How Fast Does Opened Protein Powder Lose Potency?

Opened protein powder will stay fresh and retain its quality as long as you store it in a cool, dry place and pay attention to the sell-by date.
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Remember that massive tub of protein powder you bought on sale last year? Well, you might be wondering if it's still safe to consume expired protein powder two years later, or shortly after the expiration date, especially if the container is still full.

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Opened protein powder will stay fresh and retain its quality as long as you store it in a cool, dry place and pay attention to the sell-by date.

Best-If-Used-By Date

Many consumers are looking for answers to expired protein shake questions. The good news is, there are government guidelines you can follow when it comes to quality and safety. Plus, most product websites explain what their use-by date means in regards to potency.


A food that you can store safely at room temperature is called shelf-stable, according to the United States Department of Agriculture (USDA). Other than infant formula and some baby food, the Federal regulations do not require companies to print a use-by, sell-by, or best-if-used-by date on their product. That said, some states do require the dating of some foods.

The USDA says products containing a use-by date may still be safe after that date, but it may not be of acceptable quality. To help preserve the quality, always store protein powder in the container it comes in.


It's also a good idea to keep protein powder in a cool, dry place that is out of direct sunlight and away from heat. Kitchen cupboards and pantries are top picks. Plus, keep the scoop in the container and don't use a wet measuring cup. If you feel the need to wash it, make sure it is dry before you return it to the container. Water will make the powder clump.

Read more: 8 Things to Consider When Choosing a Protein Powder and Our 5 Top Picks

Expired Protein Shake Questions

Before you stock up at an out of date protein powder sale or blend up your morning smoothie, make sure you know the ins and outs of what to look for in a powder that is reaching its sell-by date. One way to know if expired whey protein is still good is to let your senses guide you.


If it smells rancid, moldy, or just plain foul, consider getting rid of the powder. Also, if it tastes different, but not in a good way, and it's past the expiration or use-by date, you may want to think twice about adding it to your smoothie. Finally, if water or any other liquid has mixed in with the powder and it is clumping, watch for mold.

You can check the product website for any information on safety, potency and quality. For example, the Designer Protein website states that their powder should not be consumed past the "enjoy by" date.


They further explain that this recommendation is based on the testing done to determine the length of time the protein powder retains its flavor and nutrient properties. Therefore, they only guarantee freshness and nutritional quality up to that date. These statements are similar to other protein powder product labels and websites.

Read more: How Much Protein Powder Should I Drink?

Overall Safety of Protein Powder

In general, protein powder is fairly safe, according to the Mayo Clinic. However, since protein powder is a dietary supplement, the U.S. Food and Drug Administration (FDA) is not required to approve the marketing claims for safety or effectiveness before the product sells.

In September 2018, Harvard Health reported on a paper from the Clean Label Project that discussed the toxins found in protein powder. Based on research they conducted, the group found that several protein powders contain heavy metal, pesticides or other contaminants.

These examples reinforce the need to be a cautious consumer, which means reading everything on the product label before using it, especially when looking at expired protein powder two years later than its use-by date. It also means you need to pay attention to the smell, taste and texture of the protein powder after the use-by or sell-by-date. Additionally, if the product has not reached its expiration date and you notice any unusual smells, tastes or appearance, take the protein powder back to where you purchased it.

If you have any questions or concerns, it's always a good idea to talk with your doctor or healthcare provider prior to using any dietary supplement, especially if you have an existing health condition, dairy allergy or take medication.