Have you ever wondered, "how long do protein shakes last? How long can you store it in the fridge? Does it lose its potency over time?"

Leaving it for too long can lead to unpleasant surprises like an odd smell, strange texture, and upset stomach.

Don't worry; I'm not here to scare you off protein shakes forever. With proper storage and handling, it can last for a long time.

Let's cover the best practices for storing and using protein powders and some warning signs to watch out for.

Think of protein shakes like bananas. You wouldn't keep a ripe banana in the fridge for weeks and expect it to stay fresh, would you? The same goes for protein shakes. While they won't turn brown and mushy, they can still spoil over time.

Exactly how long a protein shake stay good depends on where you store it and what you mix it with.

After Mixing With Water Or Milk

When you mix protein powder with cold water or milk, it's best to drink your protein shake immediately. It's not like you're cooking a stew that takes you hours to prepare. 

You only need a few minutes to mix a protein shake, so do it when you intend to drink it or in the next 15-20 minutes.

It's not just about shake going rancid but also about taste. The taste is the finest in the first few minutes, so drinking it before your workout makes sense for the best results and taste.

Most people use water, dairy milk, soy/almond milk, or orange juice for protein shakes.

There is no significant difference between all these liquids. For example, it would be logical to expect spoilage bacteria to grow faster in dairy milk than in plant-based milk.[1]

While true, you can get food poisoning from both in a relatively similar time frame if left unrefrigerated.

When Refrigerated

If you prepare breakfast and pre-mix a protein shake the night before to ensure proper nutrition in the morning and a convenient snack, I admire you.

Protein shakes can last in the fridge for two to three days. Refrigeration (cold environment) will prevent or significantly slow down bacteria growth, so it will be safe to drink.

The shaker or whatever you keep it in should be air-tight, or when exposed, your protein shake will smell like ham and other things you store in the refrigerator.

When you take it out of the fridge and want to drink it, it would be best to shake the refrigerated protein shake again or re-blend it because the texture will not be ideal.

Protein Shake Recipe Using Beast Protein Powder

If Left At A Room Temperature

Now, you might be thinking, "I'm not worried about my protein shake going bad; I finish it in one gulp!" Well, good for you, champ!

Still, sometimes life gets in the way since we don't live in an ideal world. And then you might forget you left at room temperature half-drunk shake.

If you Google “how long does a protein shakes last after mixing?” you will find many tips on how long you can leave it at room temperature before it becomes harmful.

Most will tell you approximately two hours, and some claim nothing will happen even after four or five hours.

While that might be true, I wouldn't take a risk. If you have ever had food poisoning, you know how unpleasant it is. So why would you risk that happening for one scoop of protein, even if the probability is low?

Just drink it as soon as possible, and everything will be fine - especially your stomach and daily protein intake.

How To Tell If My Protein Shake Is Bad?

You don't have to be Sherlock Holmes to tell if your protein shake is bad.

Any change in taste, consistency, or smell is a red flag.

Determining whether the taste and smell are fine when you first buy a new protein powder flavor could be tricky, but even if the flavor differs from the one you usually consume, it must not be noticeably unpleasant.

If shakes taste weird, acidic, or bitter, that means they age badly, and it is not drinkable.

You also have to ensure that water or milk is not the culprit instead of protein. I once threw away half a container of protein powder, only to realize the milk was spoiled. So, pay attention to other signs as well.

Using Expired Protein Powder: Is It Safe?

Expired protein powders probably won't make you sick, at least during the first few months. The date indicated on the packaging is "best-before" rather than the expiry date.

The difference is significant. "Best-before" dates suggest the date by which flavor, protein quality, and other features are at their peak.

After that, you can still use protein concentrate for some time, but the amount of protein per scoop will decrease. This is because amino acids will begin to break apart, progressively affecting the protein concentration.

I think using it a month or two after the expiration date is OK. To avoid using expired protein or throwing it away, buy the amount you can finish on time. Don't buy a 10-pound pack that expires in 20 days.

All this does not apply to ready-to-drink protein shakes. Consume them only by the date set by the manufacturer.

Best Practices for Storing Protein Shakes

There is no way to make your protein shake last forever. However, if you adhere to the following best practices, you will significantly extend its shelf life.

And not only that, but you will also ensure the perfect taste and maximum protein content.

Don't Leave Them Out For Extended Periods

Never leave it out for extended periods! Especially if you have already mixed protein powder with milk or water and now it is ready for consumption.

Just like you wouldn't leave an omelet, meat, vegetables, or other whole foods on the kitchen table for 5 hours, don't do that with a protein shake either. It is food, after all, only dehydrated.

Avoid Adding Fresh Ingredients

Adding fresh ingredients like fruit to the blender, together with the best protein powder, might look like a fantastic idea to help you build muscle.

Smoothies are undoubtedly highly nutritious, and I do not advise you against making one.

However, drink it immediately or refrigerate it. Do not let it stay out at room temperature. Fruits and other ingredients, especially fresh ones, will make it go bad much faster.

Keep Them In A Cool And Dry Place Away From Direct Sunlight

You will find instructions on each supplement and medicine to store it in a cool and dry place away from direct sunlight.

The same goes for whey protein, brown rice protein, or whatever protein powder you use. If there is anything that can affect the quality and safety of protein shakes, it is heat and humidity.[2]

Bonus Tip: Clean The Shaker Properly

Properly cleaning the shaker/bottle after consuming a protein shake is more important than you think.

It often happens that tiny pieces of powder "hide" somewhere in the shaker, and if you fail to wash each part, you can get poisoned next time. Pay special attention to the whisk.

Protein Shake Accessories and Protein Powder

Common FAQs About How Long Do Protein Shakes Last

How long do protein shakes last after expiration date?

In theory, an unopened protein shake may last even two years past expiration date. However, protein content will be significantly lower as time goes by due to degradation, and that affects muscle building process. In general, rely on your sense of taste and smell, and only then on the expiration date that should never exceed one year.

Does mixing a protein shake with water make it last longer than if mixed with milk?

The liquid with which you mix a protein shake will not significantly affect how long it will last. Animal milk is more prone to bacteria than cold/hot water and plant-based milk, but the difference is minimal.[3]

Do protein shakes need to be drunk immediately?

You don't have to drink it immediately but should do it within an hour. If you plan to drink it a few hours later, storing it in a fridge is advisable to slow down bacteria growth. A spoiled protein shake can cause diarrhea.

How long does protein powder last once opened?

If you keep it away from excessive heat and moisture, protein powder will last at least six months, probably more, once opened.

So, How To Keep Your Protein Shake Fresh?

Always check the expiration date on the label before purchasing and store it in a cool and dry place. Keep protein powder in the original container.

After mixing the shake, don't leave it at room temperature for too long to prevent the growth of harmful bacteria. Consume it within an hour or store it in the fridge.

If your protein shake smells or tastes unusual, toss it away. It's always better to err on the side of caution and avoid consuming anything that doesn't feel right. You know what they say; "when in doubt, throw it out."


  1. https://www.intechopen.com/chapters/75536
  2. https://pubmed.ncbi.nlm.nih.gov/26778305/
  3. https://www.journalofdairyscience.org/article/S0022-0302(16)30023-6/pdf
Miloš Lepotic

Miloš Lepotic

Meet Miloš, a certified sports nutritionist and self-taught supplement expert whose pharmacological background and nearly a decade of gym experience make him the perfect guide for optimizing your health and athletic performance through supplement reviews and practical advice rooted in factual, science-backed information.