Does Protein Powder Go Bad? Does Protein Expire?

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Can Protein Powder Go Bad? Protein powder is unlikely to grow bacteria as it’s a dry product. However, when exposed to moisture such as condensation from refrigeration, it can grow mold or turn musty.

Protein powder that develops clumps may have turned musty. If it smells bad, discard it. If a dab of dry powder tastes of paper or cardboard, dump it.

Do not refrigerate whey protein powder, as this will cause condensation and introduce water to your protein powder. Keep it in the original container and store it in a cool cupboard. Keep the product sealed when not using it.

Does Protein Powder Expire?

Protein powder can oxidize. If you purchase whey or casein powder, or invest in a blended vegetable protein powder, you’ve bought a complete protein. If it’s allowed to oxidize, it’s now an incomplete protein.

While it may not become unsafe to mix into a drink for quite a long time, ingesting an incomplete protein defeats the purpose of using a protein powder.

Fitness experts with Men’s Health offer a simple taste test to determine if your protein powder has lost its oomph: taste a bit of the dry powder.

If it tastes like cardboard, the lysine in the protein has started to break down, and the powder will not deliver the complete protein you need.

How long does protein powder last?

It might be edible for up to a year after the use-by date, but it will not be as effective as when it’s fresh.

Vegetable-based protein powder such as soy, brown rice, or hemp are not complete proteins. If you’re planning to mix your own vegetable-based protein powder, be aware that you may be introducing more of the product to air in the blending process.

When possible, mix the powders as little as possible, or purchase two smaller containers and blend them as you make your shake.​

How Use & Store Whey Protein

does whey protein expire

Both casein and whey protein provide a complete protein, both are produced and packaged with a use-by date, and both can be safe to ingest up to a year after the use-by date. Oxidation will impact both of these products and reduce their potency after the use-by date, however.

When handling any protein powder, take care to store it sealed in a cool cupboard. When considering how to store protein powder, be aware that this storage restriction applies to whey, casein, and vegetable-based powdered protein supplements.​

Per Protein Report protein shakes should only be mixed for one day at a time, and once mixed, must be refrigerated. If your protein powder is still in date but has started to lose flavor, it can still be used in cooking.

Whey and casein protein provide different benefits when used correctly. Casein takes longer to digest, and whey works in shorter bursts.

If you choose to use both products at different times of the day, fitness expert Dr. Axe recommends using casein before sleeping and whey after your workout to reduce muscle soreness.​

If a full breakfast after your workout doesn’t work with your schedule, a well-balanced shake loaded with whey protein, casein protein, simple and complex carbohydrates and glutamine can help your muscles recover.

This will also help keep your energy level consistent and high until you have time for a balanced meal.

Final Thoughts​

Keep all protein powder sealed and store it in a dry environment and it can keep up to 12 months past the use-by date, though it may lose potency.

Vegetable based proteins including brown rice and hemp are available for vegans and those with lactose intolerance.

Protein powders are a great way to make a nutritious, portable meal for people on the go. If you find yourself sore after your workouts, a whey and casein protein shake may be just the boost you need to reduce your pain while building muscle.​

Written By Tara Williams

Tara is a food writer that has been editing and authoring articles for KitchenSanity since its founding. Her writing offers personal experience from experimentation with food and recipe creation. If you’re looking for simple tips, she will make your journey in the kitchen straightforward with a dash of fun.