When it comes to whey protein powder, there are a few key signs that will indicate whether or not the powder has gone bad. First and foremost, you'll want to take a look at the expiration date on the container. If the powder is past its expiration date, then it's likely gone bad and you'll want to discard it.
Another sign that whey protein powder has gone bad is if it has changed in color or consistency. If the powder is no longer a uniform white color, or if it has clumped together, then it's probably time to get rid of it.
If you're unsure whether or not your whey protein powder has gone bad, err on the side of caution and toss it out. It's better to be safe than sorry when it comes to consuming expired or spoiled food products!