Food safety experts and microbiologists have good news for you: The date stamped on the package is a quality date, not a safety date.

"Thats when the manufacturer believes its going to be the tastiest for you," says Mitzi Baum, CEO of Stop Foodborne Illness and an adjunct instructor on food safety at Michigan State University. "Consumers have a misunderstanding about what those dates on those foods actually mean."

It also means you are free and clear to keep using your protein powder weeks and even months after the "use by" date on the container. Its such a dry product that its fairly inert, like a canned product, says Jennifer Quinlan, Phd, a microbiologist and associate professor in the department of nutrition sciences at Drexel University.

Dry products like protein powder have a very low risk of making you sick, Baum adds.

Okay, it's safebut is expired protein powder still effective?

So, it wont send you to the ER...but will the powder still help you build muscle and take in more satiating protein? Again, there's good news here: Protein is proteinits amino acidsso its not going to break down into something else, says Quinlan. I dont see any reason to think that thats going to be a problem in terms of the protein. The carbohydrates in it are also not going to change over time, either.

Not all ingredients are as stable, though. The bigger thing to be concerned about is fat, says Quinlan. They do have fat in there because you need it. The fat could go rancid, if you let it sit too long.

How can you tell if you're on the wrong side of "too long"? Your nose will tell you if the fat has gone rancid. It could smell and its certainly not pleasant, says Quinlan. So if your protein powder smells off, she wouldn't recommend using it. (More on that below.)

Whether you're using a plant-based protein powder, a dairy-based formula, or something else, the micronutrients (aka vitamins) are likely to decline over time. Vitamins might not be as effective, if its two years later, Quinlan says.

How can I keep protein powder fresh longer?

There are a few ways to extend the life of your favorite flavors:

  • Always store protein powder in the container it comes in. The dark or opaque packaging protect the contents from light
  • Place the container in a cool, dry place , like a cupboard or pantry. Alternatively, you can also store protein powder in the freezer to preserve the fats longer, says Quinlan.
  • Dont store protein powder on top of the fridge. The mechanical heat and humidity there will shorten its shelf life.
  • Make sure the spoon or scoop you use is always dry. If you introduce water into the container, theres a possibility of mold growth," says Quinlan. Mold, which might look like a powder clump, can lead to bacterial growthand any protein powder with mold should be discarded immediately.

In a post-workout smoothie rut? Check out these ideas:

What are the signs that a protein powder has actually expired?

Since you can't rely solely on the date on the container, use all of your senses to check it out:

  • Check for a foul odor , which indicates the protein powder has spoiled. Typically your nose will give you the first clue," says Baum.
  • Look at the texture. Clumping equals a bad sign, as it might be a sign of mold, says Quinlan. Baum adds that any change in texture is an indication that you should probably throw the protein powder away.
  • If it tastes off, toss it. But you knew that, right?