Does protein powder go bad?

With so many flavors and types of protein powder out there, it’s understandable that you probably want to try them all to find the best protein powder for you. 

(Trust us, we get it — Gainful offers customizable protein powders and a variety of Flavor Boosts for a reason!) 

But that curiosity might leave you with a stash of protein that you’ve used only once or twice. Or maybe you used a protein powder consistently for a month but then moved on to the next. So what do you do with your extra protein powder? Will your protein powder go bad?

Whether you try to use them up yourself or pass them along to a friend who’s curious about protein powder, a main concern is that the old protein powder is still OK for consumption. But does protein powder go bad? What happens if you consume expired protein? 

How long does protein powder last? Whey protein vs. vegan protein

According to the most recent research, protein powders like whey protein powder have a shelf life of nine to 19 months when stored under normal conditions. These normal conditions are defined as 70°F and 35% humidity. If a protein contains additives, that can extend the shelf life for up to two years. 

Unlike whey protein or casein protein, plant proteins like hemp, pea, and soy do not contain milk or dairy. The exclusion of milk ingredients eliminates significant bacterial concerns. Vegan proteins generally keep better than whey protein, with a shelf life of two years, or 24 months. 

However, nearly all protein powders — from whey protein to pea protein — are low-moisture foods, so they’re less prone to bacterial growth in general. As long as you consume your protein powder within a few years of purchasing and store it in a place that’s cool or room temperature, you probably won’t have to worry about dry products like protein powder going bad. 

But what happens when you store your protein powder in a place that doesn’t meet “normal conditions” standards? In a 2016 case study, researchers monitored the physical properties of two batches of whey protein concentrate under less-than-ideal storage conditions in an effort to learn how hot, humid areas affect protein powders’ shelf life. Whey protein concentrates with 34.9 g of protein/100 g and 76.8 g of protein/100 g were stored for up to 18 months under conditions such as elevated temperature and high humidity. The samples became yellower much earlier than they would have under normal conditions. Those stored at 95°F were actually removed from the study within a year because of their concerning appearance. When stored in sealed bags, the samples had a shelf life of around nine months at 95°F. The study concluded protein powders can go bad before the listed expiration date if they’re not stored under cool and dry conditions. 

Best way to store protein powder and extend its shelf life

You’ll want to keep your protein powder in a cool, dry environment with the temperature as close to 70°F as possible. Kitchen pantries are usually a safe bet. 

If you place your protein powder in a space that’s typically warmer than 70°F, you run the risk of spoilage or shortening your protein powder’s shelf life. Also avoid any area with high humidity or moisture. You’ll want to keep your protein powder in a dry place.

Do protein powders have an expiration date?

Similar to spoiled foods, protein powder that has gone “bad” will often have several signs. 

Signs that protein powder has gone bad include:

• rancid smells 

• bitter taste

• changes in color 

• clumping 

Although supplements are not required by the Food and Drug Administration (FDA) to label their products with an expiration date, many brands do. They want their customers to have realistic expectations of the quality of their product. But depending on how you stored your protein powder, your products could go bad earlier than the listed expiration date. That’s why it’s more important to pay attention to how your powder looks and smells than the date printed on your product. If you open up the container of protein powder and it smells bad or has wet lumps, toss it — no matter what date is listed.

Can expired protein powder hurt you?

Can old protein powder make you sick? As mentioned above, the FDA does not require supplement brands to include expiration dates on their products, but many do anyway. It’s important to note that these expiration or “use by” dates are usually not indicators of safety, but rather, they’re there to ensure quality. These dates tell customers how long the product will be its best quality, not necessarily when it will go rancid. 

Keeping this in mind, consuming protein powder shortly after its expiration date is likely safe if the product has been stored properly; however, protein powders can lose protein content with age. So if you consume a product after its expiration date, it might not be of the best quality. Lysine, an amino acid in the protein that aids muscle building, can start to break down over time via a process known as the Maillard reaction. When amino acids like lysine break down, it makes the protein powder less effective. 

What happens if I leave out a protein shake? Does protein powder expire quicker when mixed with other ingredients?

You can store a bag or tub of dry powder in a cool pantry for up to two years, but what if you use that protein powder in shake? How long can you leave your protein shake out and safely still drink it? 

The short answer: If you mix your protein powder with your favorite liquid, you’ll want to consume it right away. You can probably stick a protein shake in the fridge for a few days, but if you leave the shake out in a warm or hot environment, you are not going to want to drink the contents after a few hours. So if you made a drink, set it down, but then forgot about it for a few hours, you’ll want to dump it and just make a new one. Wash the shaker bottle or container, and start over with a fresh protein shake.

Expiration dates on protein powder packaging are for the dry protein powder, not a protein shake. Once you mix it with other food products — especially perishables like milk or produce — the expiration date of the powder no longer applies.

Ways to use protein powder before it expires

Protein powder doesn’t have to just go in shakes or smoothies. Protein powders mix well into a variety of recipes. Bonus: Using protein powder in a baked treat or a snack can actually improve its nutritional profile, especially if your favorite foods are carb-heavy. Add your protein powder to baked goods, oatmeal, pancakes, waffles, pizza crust, frittatas, quinoa breakfast bowls, peanut butter balls and more. Sneaking a scoop of protein into your favorite foods is an easy way to use your protein powders up before they go bad and improve the nutritional makeup of the food in the process. You can also consult a nutritionist for more ideas or ways to use any extra protein powder before it expires.