Protein powders usually have a listed expiration date of 1 to 2 years after production. Consuming it shortly after an expiration date is likely safe if there are no signs it’s gone bad.

Protein powders are among the most widely used dietary supplements by athletes, bodybuilders, and the general population. They come from a variety of animal- and plant-based sources, including:

  • milk (whey or casein)
  • soy
  • collagen
  • pea
  • rice
  • egg white

Protein powders also contain varying levels of other essential nutrients, including fats, carbohydrates, vitamins, and minerals.

Plus, they generally contain additives, including natural and artificial flavors, flavor protectors and enhancers, and thickening agents, which help extend a product’s shelf life and provide a creamier consistency and mouthfeel.

Still, depending on how long that tub of protein powder has been in your kitchen cabinet, you may wonder whether it’s still good or safe to use.

This article discusses whether protein powder expires and if it’s safe to consume beyond its expiration date.

A note on protein powder supplements

The Food and Drug Administration (FDA) doesn’t require supplement manufacturers to include expiration dates on their products.

Many companies provide an expiration or “best by” stamp along with a manufactured date. In these cases, they must support the expiration date of their products with data to demonstrate that it’s not misleading.

However, since the FDA doesn’t regulate the quality, quantity, or type of ingredients in supplements, it’s important to remember that a manufacturer’s claims might not always be accurate.

Shelf life refers to the period during which food retains its optimal quality after production. Several factors may influence the shelf life of protein powder, such as:

  • the temperature and humidity of the environment in which the protein is stored
  • the intrinsic composition of the supplement, including its natural and added ingredients

Researchers typically use accelerated shelf life testing to measure and estimate a product’s stability by storing it under stressful conditions, such as high temperature and humidity.

Researchers in a 2005 study used an accelerated shelf life test to find that whey protein powder has a shelf life of more than 12 months, even up to 19 months under storage conditions of 70°F (21°C) and 35% humidity.

In a 2016 study, researchers concluded that whey protein has a shelf life of 9 months when stored at 95°F (35°C) but at least 18 months when stored at room temperature, or 70°F (21°C) with 45% to 65% humidity.

It’s still unclear whether the suggested shelf life of whey protein applies to other sources of protein, but it’s likely similar if they are stored under the same conditions.

In either case, most protein powders on the market contain additives that increase shelf life, such as maltodextrin, lecithin, and salt, allowing for a shelf life of 1 to 2 years.

With the exception of infant formula, expiration or use-by dates are not indicators of safety, but quality.

Protein powders are low moisture foods, meaning they’re less prone to bacterial growth, according to a 2016 review.

While consuming protein powder shortly after its expiration date is likely safe if the product has been stored properly, protein powders may lose protein content with age.

A 2016 study found that the amino acid lysine in whey protein decreased from 5.5% to 4.2% in 12 months when stored at 70°F (21°C) with 45% to 65% humidity.

However, the protein powder used in this study did not contain any additives that many products on the market use to extend their shelf life.

It’s also possible for protein powder to spoil before the listed expiration date, especially if it’s not stored under cool, dry conditions.

Some research has found that protein powders stored at higher temperatures (around 140°F, or 60°C) are more likely to cause the nutritional composition of the protein powder to break down more quickly.

A 2008 study also found that when whey protein was stored at 113°F (45°C) for 15 weeks, there was a significant increase in oxidation, which led to the production of various compounds that cause undesirable changes in taste.

Oxidation — the reaction of fats with oxygen — increases with storage time and damages the quality of protein powders. High temperatures are conducive to oxidation. Research suggests that oxidation doubles for every 50°F (10°C) increase.

Signs that protein powder has gone bad include a rancid smell, bitter taste, changes in color, or clumping. Similarly to eating spoiled foods, consuming protein powder with one or more of these signs — regardless of the expiration date — might make you sick.

If you notice any signs that your protein powder has gone bad, it’s best to throw it out.

Protein powders are popular supplements that come from a variety of animal- and plant-based sources.

They have a shelf life of around 1 to 2 years, which is likely extended due to the use of additives. It’s essential to note that the shelf life of the protein powder decreases once the tub has been unsealed and opened.

Consuming protein powder shortly after its expiration date is likely safe if there are no signs that it has gone bad, which include a rancid smell, bitter taste, changes in color, or clumping.

If these signs are present, it’s best to toss your tub and purchase a new one.