Does Protein Powder Expire? Warning Signs and What to Do

Does Protein Powder Expire? Warning Signs and What to Do

Protein powder is vital for athletes and active individuals alike who are looking to build lean muscle, enhance strength, or reach other fitness-related goals. However, when purchasing a protein powder, it’s important to pay attention to the label.

While the label offers many important facts about the protein (including nutrition, ingredients, manufacturing process, etc.), one of the most important details to look out for is the expiration date. In fact, one of the most common questions asked about protein powder is whether or not it can expire, and if so, when? 

Can Protein Powder Go Bad?

Long story short, yes. While it is a convenient supplement, it won't last forever.

With all the different kinds of protein powder out there today, how do you know what to look for?

We’ll answer all your questions and more.

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How Long Can You Keep Protein Powder?

Unfortunately, protein powder doesn’t last forever. No matter how you might store it, it's bound to go bad eventually. 

With that said, it has a much longer shelf life than most foods and can stay fresh for a rather long time. 

Most protein powders typically last for around two years. However, there are a wide variety of protein powders out there. What about vegan protein powders? If you’re a fan of plant-based protein, the same two-year rule still applies. 

So how do you know when the two-year mark is up? Most protein powders will print the date on the canister. You can usually find a batch number listed along with a Julian Date. The Julian Date is a three-digit code that represents the consecutive day of the year. For example, January 1st is labeled as 001, while December 31st is labeled as 365.

Can You Use Protein Powder After The Expiration Date?

While protein powders do provide expiration dates, it’s not a super strict date. Since protein powder is a dry powder, the chances of bacterial growth occurring (unless it’s a much later date than the expiration date), are rather slim. What may start to expire is the taste of the product. The product will still be safe to eat, but the flavor will begin to fade. 

The one factor to be aware of with expired protein powder is the Maillard Reaction. 

What’s the Maillard Reaction?

The Maillard Reaction is a chemical reaction that occurs between amino acids and sugars that results in the browning of food, forming new flavors and smells. In the case of expired whey protein and plant protein, it is specifically the breakdown of lysine (one of the key amino acids found in protein powder). 

Maillard browning kicks in when the protein is sitting too long, causing the breakdown of lysine. Once lysine is broken down, your protein is no longer considered complete. When it comes to noticing Maillard browning, trust your senses. If it smells or tastes off, throw it out.

How to Tell If Your Protein Powder Has Expired - Infographic 

How Long Will a Protein Shake Stay Fresh Once It’s Mixed With a Liquid?

We know that keeping protein powder stored safely will keep it fresh for up to two years. But what about once you mix it with a liquid? That’s a different story. Anyone familiar with protein shakes knows that leaving your shake in a shaker bottle for too long can create an extremely potent smell. And it isn’t a good one either.

If you’re looking to mix your protein shake with water or milk ahead of time, try not to let it sit too long, even when refrigerating (30 minutes or less). That’s rule number one. Protein shakes are meant to be consumed within minutes of mixing. If you’re taking your shake on-the-go, wait to mix it with a liquid until you’re just about to drink it. 

How Should You Store Your Protein Powder?

To keep your protein powder tasting great for as long as possible, store it in a cool, dry place and keep the lid tightly sealed. You’ll ideally want to keep it in a cabinet or pantry. Try to keep it away from the top of the fridge or stove as the heat radiating from various appliances can degrade the quality of the protein faster.


Protein powder can be an excellent tool for adding protein to your diet, improving your recovery from workouts, and increasing lean muscle. But don’t forget to check the label before you make that next protein shake. If you’re wondering if your protein powder is bad or not, check the expiration date and do a quick taste and smell test so you don’t risk gulping down a bad shake.

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