Protein powder does go bad eventually however, it may keep for months or years past the expiration date on the bag or tub. If the protein powder is well past the expiration date be sure to check for evidence of moisture getting into the powder such as clumps or bad smell. If the tub is still sealed with no sign of moisture, it is more than likely ok to eat.
Why Protein Powder Goes Bad
Most protein powder contains eggs or dairy by product such as whey or casein protein. Even though it is in powder form, these ingredients will eventually go bad if exposed to moisture or stored in a damp, warm environment. If kept in an unopened container, it could be safe to consume however from a muscle building point, it may not be as effective. Some of the amino acids within the protein powder will eventually break down due to the sugar after time so the effectiveness of the protein will decrease. The best way to tell if your protein has amino acid breakdown is the amount of flavor that you taste in the powder. When your powder is expired and tastes like cardboard, it is probably not working for your body the way it was designed.
If you are still wondering if you should toss your protein powder, we have a few handy tips. It may say it is expired but not up to a full year yet, the flavor will start to fade. This is a good time to use the protein powder in baking and cooking to add a little extra protein without having to rely on the taste of the powder. Experts say if the expiration date is more than a year old, it is better safe than sorry. Toss out the protein and find something that you will eat faster. The type of protein powder that you have will also play a role in the time that it takes to go bad. Isolates have less carbs and fat than a concentrate making them less likely to go rancid.
For the best results of longest lasting powder, keep the powder in a cool dry place such as a cupboard. Keeping protein powder on top of the fridge is one of the worst places since it gets hot and moist.