Is It Bad To Drink An Expired Protein Shake? (Yes, Here’s Why)

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If you’ve got some tubs of protein powder collecting dust in your pantry, or a pallet of ready-made protein shakes, you might wonder if it’s still a good idea to use that powder or drink those shakes after the expiry date.

Yes, it’s a bad idea to drink an expired protein shake or make a shake with expired protein powder because the shake would be less effective and you’d increase the risk of getting sick. It’s safer and more effective to toss out expired products and stock up on new ones instead.

Key Takeaways

  • Dairy-based protein powders have a very long shelf life (1-2 years) as long as they are properly stored, and most plant-based protein powders last even longer.
  • A best-before date indicates that a product is most fresh before that specific date, but does not mean that the product is no longer safe to consume after that date.
  • Consuming a protein shake that has expired can make you extremely sick, so if you suspect your protein is expired then throw it out.

What Are The Expiry Dates On Protein Powders & Shakes?

Homemade Protein Shakes

Homemade protein shakes expire the fastest because once a protein shake is mixed it needs to be consumed within 2 hours at room temperature, or within 72 hours (3 days) if stored in the refrigerator. 

However, your fridge needs to be 40 degrees Fahrenheit (4 degrees Celsius) or colder and your shake is in an airtight container for the best results.

Check out my other article I Left My Protein Shake In the Fridge Overnight for more tips on how to make homemade protein shakes last longer and taste better.

Ready-Made Protein Shakes

Ready-made protein shakes are usually good for a bit longer than homemade protein shakes, as long as they remain unopened.

That said, the shelf life of ready-made protein shakes will depend on whether they are designed for storage at room temperature, or whether they require refrigeration. 

  • Ready-made protein shakes that can be stored at room temperature have an average shelf life of 12 months.
  • Refrigerated protein shakes are usually good for 2-4 weeks, if unopened (if open, consume within 72 hours).

Most ready-made protein shakes do require refrigeration until opened, which may surprise you because many retailers store them in the fridge but this is simply because they taste better cold.

For example, Fairlife Core Power protein shakes are shelf stable at room temperature, so as long as they are unopened, they have a shelf life of 9-12 months (check the label for the specific date).

Once ready-made protein shakes are opened, they will expire at the same rate as homemade protein shakes (within 2 hours at room temperature, or up to 3 days if refrigerated). 

Dairy Protein Powder (Whey & Milk Protein Powder)

Dairy-based protein powders like whey isolates, whey concentrate, milk protein powder, or blends of these protein powders usually have an expiration date that is at least 1-2 years away.

Keep in mind that this date assumes that the powders will be properly stored in a tightly sealed package in a cool, dark location, away from high temperatures and/or humidity.

If the package isn’t tightly sealed, air can get in and cause oxidation of the powder (when it reacts with oxygen), which can make the protein powder rancid and foul-smelling.

High temperatures also deteriorate the quality of the protein by causing the amino acids in it to break down (most notably the amino acid lysine).

And finally, if the protein powder is damp, it will start to clump and crystallize, and it’s more likely to get moldy.

Even if the expiry date hasn’t passed if you notice your protein powder is clumpy, has started to change color, or if it smells “off” in any way, it’s time to ditch it and buy some new protein powder.

Non-Dairy Protein Powder (Brown Rice, Hemp, Pea, etc.)

With the exception of soy protein powder, which has a shelf life more similar to whey protein powder, most plant-based protein powders have an even longer shelf life than dairy-based protein powder.

Most plant-based protein powders have a shelf life of at least 2 years so it takes longer to expire. However, this assumes that the protein is being properly stored in a cool, dry, dark location in a tightly sealed package.

What’s The Difference Between “Best-Before” And Expiration Dates?

A “best-before” date will tell you the last recommended day for the best flavor and quality, but it’s still possible that the product is safe to consume after its best-before date. On the other hand, an expiry date tells you the last day a product is safe to eat. You should NOT eat anything after the expiry date.

It’s also important to know that “best-before” dates assume that the product has been properly packaged and stored.  If a product says that it should be stored unopened in a cool, dark location, then the best-before date will not apply if it’s been left open in the sun.

Expiry dates are not the same as best-before dates. Expiry dates apply to products where the nutritional value of the contents cannot be guaranteed past a certain date. This means that after the expiry date, the food may not have the nutrient content described on the label.  

In the US, the Food & Drug Administration (FDA) does not require expiration dates on anything other than infant formula, so it’s up to manufacturers to come up with the dates listed on protein supplements.

I always tell my clients “when in doubt, throw it out” because it’s not worth getting sick if you’re unsure about whether your protein is expired.

Are Expired Protein Powders Still Effective?

No, expired protein powders cannot be guaranteed to be effective, since their nutritional content may be different from what is on the label as its contents start to degrade. 

Plus, not only are they less likely to be effective, they are more likely to be unsafe because of the risk that they can make you sick.

Can You Make A Protein Shake With Expired Protein Powder?

Technically, you can make a protein shake with expired protein powder, but you absolutely should not. I would never recommend that anyone make a protein shake with expired protein powder.

If the protein powder is expired, then there is a risk that it is harboring dangerous bacteria that can make you sick.  

Even if the protein powder smells and looks okay to you, it’s likely not the same quality as when it was new and isn’t going to give you the same benefits. Time to shop for new protein powder!

What Happens When Protein Shakes Expire?

It’s not as though there is an off switch that happens immediately on the expiration date for protein shakes (or any food). Shelf-stable food products generally deteriorate slowly over time, with the quality diminishing just a little bit at a time (fresh food products, or “perishable” items, degrade much more quickly).

So, what is happening to protein powder or sealed ready-made protein shakes when they sit on the shelf for months on end?  Here are the ABCs of expiry (amino acid breakdown, bacterial growth, and crystallization):

Amino Acid Breakdown

Even without high temperatures causing amino acids to break down as I described above, over time, chemical reactions will slowly deteriorate the amino acids in protein powder or protein shakes, so that you don’t end up getting the benefits of these building blocks for muscle growth. 

Bacterial Growth

Next up, you run the risk of bacterial growth, especially if your protein isn’t properly sealed.  If you see any blue, green, or black flecks in your protein, it’s a sign of mold spores, and you need to get rid of it right away.

Don’t think you can just scoop away the colored parts – smaller particles that you can’t see with your eyes can be distributed throughout the entire product.


You’ll notice crystallization most commonly in protein powders and not protein shakes. Crystallization can be identified when you start to see clumps or notice a gritty texture to your protein powder which is different than normal.

This happens most often when a bit of moisture gets into the powder, such as from a humid environment. Unfortunately, this moisture turns your protein powder into something resembling cat litter.

Related Article: Can You Freeze Protein Shakes? Quick Guide For Best Results

Six Signs Your Protein Shake Has Expired

six signs your protein shake has expired

Here are half a dozen tell-tale signs that your protein shake has expired:

  1. The date: if the expiry date on either your protein powder or ready-made protein shake has passed, it’s better to be safe than sorry and discard the product, even if it looks and smells fine to you.  It’s not worth risking your health over a “sniff test.”
  1. The smell: an unpleasant, funky, or rancid smell can be one of the first clues that your protein shake is no good.  If you ever forget to wash your shaker cup for a few days, you’ll recognize this pungent odor.
  1. The taste: similar to the smell, if your shake doesn’t taste quite right, it’s time to trust your taste buds, ditch the shake, and start with fresh ingredients.
  1. The color: if your shake has started to turn color, especially if it looks more brown, green, purple, or gray, toss it!  Protein powders that start out white in color (like vanilla), will start to get more yellow over time, too, and it’s a sign to get rid of them.
  1. The texture/consistency: if your shake has separated into solid curds or clots and liquid, it’s a sign your shake has expired. Especially if it’s a protein powder that didn’t use to clump.
  1. The gas: if the lid is starting to bulge, or you notice a release of pressure when you open the container, it’s a sign that your protein shake has started to ferment and is releasing carbon dioxide.

Can You Get Sick From Drinking An Expired Protein Shake?

Yes, you can get sick from drinking an expired protein shake.  Your symptoms can range from mild gastrointestinal discomfort like nausea, cramps, or bloating to a full-on case of food poisoning with severe diarrhea and/or vomiting, as well as fever.  If you experience serious symptoms, see your doctor right away.


Tunick MH, Thomas-Gahring A, Van Hekken DL, Iandola SK, Singh M, Qi PX, Ukuku DO, Mukhopadhyay S, Onwulata CI, Tomasula PM. Physical and chemical changes in whey protein concentrate stored at elevated temperature and humidity. J Dairy Sci. 2016 Mar;99(3):2372-2383. doi: 10.3168/jds.2015-10256. Epub 2016 Jan 6. PMID: 26778305.

John O’Brien, P. A. Morrissey & J. M. Ames (1989) Nutritional and toxicological aspects of the Maillard browning reaction in foods, Critical Reviews in Food Science and Nutrition, 28:3, 211-248, DOI: 10.1080/10408398909527499

About The Author

Lauren Graham

Lauren Graham is a Precision Nutrition Level 1 certified nutrition coach. She focuses on helping busy professionals balance healthy eating and purposeful movement.  Lauren has a background in competitive swimming and is currently competing as a CrossFit athlete.  She has a passion for training, teaching, and writing. 

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