How Long Does Protein Powder Last After Opening? 

Protein powders provide a practical and reasonably priced way to increase your protein intake. They come from various sources, such as milk (in the form of whey or casein), soy, collagen, pea, rice, and egg whites. 

Although protein’s positive impact on muscle growth receives the most attention, research still reveals other advantages of eating more protein, such as fat loss, blood sugar, and many more. 

Additionally, these come from a variety of animal and plant-based sources. They often contain additives to improve and preserve their flavor and texture.

Depending on a tub of protein powder’s shelf life or how long it has been sitting in your kitchen cabinet, you may wonder if it’s still good or safe to use. This article is here to explain it. 

What Happens When Protein Powder Expires?

Foods like protein powders have little moisture content, making them less likely to support bacterial growth.

Many protein powder makers specify an expiration date of two years after production, even though research suggests that whey protein has a shelf life of nine to 19 months. This duration is probably made feasible by additions that enhance shelf life.

Moreover, if there are no indications that the protein has gone wrong, such as a rotten smell, unpleasant taste, changes in color, or clumping, eating it soon after its expiration date is probably safe.

If any of these symptoms are present, you must replace them immediately. Protein powders can lose protein content with time. However, if you stored the product correctly, it is probably safe to consume it even after the expiration date.

Common Types of Protein Powder

How Long Does Protein Powder Last After Opening?

1. Whey Protein

Milk is the source of whey protein. During the manufacturing of cheese, the liquid separates from the curds. Although it contains lactose, a milk sugar that many people find digestible, it is also abundant in protein.

Furthermore, it is a complete protein containing all nine essential amino acids. It may also reduce appetite and promote fat loss.

2. Casein Protein

Casein is another protein found in milk, just like whey. However, casein is absorbed and processed much more slowly. When casein and stomach acid mix, a gel is created that slows stomach emptying and delays the absorption of amino acids into the bloodstream. 

In addition, casein may help with calorie restriction by promoting fat loss and muscle mass growth while reducing muscle protein breakdown.

3. Egg Protein

Eggs are an excellent source of high-quality protein. They have the highest protein digestibility-corrected amino acid score of all whole foods. However, egg whites are commonly used to make egg protein powders rather than whole eggs. 

The protein content is excellent, and the absence of high-fat yolks may cause you to feel less satisfied.

Moreover, eggs are a complete protein source, much like all other animal products. They offer all nine essential amino acids, which your body cannot produce independently.

4. Pea Protein

Vegetarians, vegans, or dairy or egg allergies are particularly fond of pea protein powder. It is produced with yellow split peas, which are high in fiber and contain all but one of the essential amino acids. It is also a good source of iron. 

While studies are limited, pea protein may promote fullness and increase muscle growth as effectively as animal-based proteins.

5. Hemp Protein

Hemp protein powder is another plant-based supplement that is popular right now. It is rich in beneficial omega-3 fatty acids and several essential amino acids. However, we do not consider it a complete protein because it has deficient amino acids, lysine, and leucine levels.

6. Brown Rice Protein

Although brown rice-based protein powders are not new, whey protein is often superior for developing muscle. Despite having all nine required amino acids, rice protein has insufficient lysine to qualify as a complete protein.

7. Mixed Plants Protein

Most protein powders comprise a mixture of plant proteins. Adding enzymes to these plant-protein mixtures may increase their digestion and absorption.

Two or more proteins are usually combined: brown rice, pea, hemp, alfalfa, chia seeds, flax seeds, artichoke, and quinoa.  Moreover, people mostly take protein powder in shakes made of fruits and milk and call them protein shake. 

How Do I Know If My Whey Protein Powder Has Expired?

Whey protein is the most popular type of protein powder. It is considered a complete protein since it contains all nine essential amino acids — the building blocks of protein.

You can find the expiration date on the package of the whey protein powder. Also, it is advisable to check for the expiration date before consumption. 

According to a study, a whey protein powder goes terrible when it develops an unpleasant odor, a bitter taste, color changes, or clumps. Regardless of the expiration date, eating protein powder that exhibits one or more symptoms could get you sick, just like consuming lousy food.

Frequently Asked Questions

Can you drink expired protein powder?

Though it is safe to consume, lysine, an essential amino acid in the protein, breaks down over time. As a result, it affects the quality. 

When protein powder gets expired, the protein may be less effective at aiding muscle building.

How long after can you use protein powder after it expires?

After opening, you can store protein powder for as long as possible. However, just be cautious when handling it to prevent spoilage, and have your protein powder stored properly. 

Although using protein powder after its expiration date may result in worse quality than when it was fresh, it is not always harmful to eat.

Can expired protein powder hurt you?

Yes, consuming protein powder that is expired can hurt you if it develops an unpleasant odor, a bitter taste, changes in color, clumps or if the protein powder smells. 

Moreover, it can cause stomach aches which may cause you to go to the emergency room. However, consuming protein powder shortly after it has expired may not hurt you. 


How Long Does Protein Powder Last After Opening?

Studies show to gauge the shelf life of protein powders to determine whether they are still safe for consumption after expiration. 

Although you can use protein powder after the date indicated on the label, it may deteriorate. Therefore, always keep your protein powder in a cool, dry place and watch for signs of deterioration like clumping or a rotten smell.

If you found this article helpful, check other fitness-related articles on

Other Related Articles:

Nathan Lloyd, MSc

I’m a personal trainer, based in Boulder, Colorado.
I service clients physically in the Boulder area, mainly in the ONE Boulder Fitness Gym, but am also available for online consulting and coaching.

If you’re interested in my personal coaching programs, please contact me via the contact page.