Is expired protein powder safe? 

Is expired protein powder safe? 

Protein powder that has recently expired is usually considered safe to take – if it doesn’t have any physical signs of degradation. The expired protein powder doesn’t really cause toxicity, but it can lose the strength of the protein added to it with time. 

Most protein powders come with a shelf-life of about 2-3 years. You may not find the date written as ‘expiry’ or ‘expiration’ date as most protein powders have the date labelled as ‘best before’ or ‘best by’. 

The shelf-life also varies with the type of protein added. Milk-based proteins like Whey protein may have a shorter shelf-life as compared to vegan proteins which can be used for a longer period of time. 

The integrity of protein powders also depends on storage conditions. According to research studies, if the protein powder is stored above 40°C, it starts to degrade way earlier than it does at temperatures lower than that (1). 

If you have a tub of protein powder at your home that is unopened but it’s past the expiration date, it is absolutely safe to use. This is because the process of degradation is usually accelerated when you open the tub and when the powder gets exposed to the environment. 

However, I can’t say the same for opened protein powder and it’s best if you avoid using it. 

What are the physical signs of protein powder degradation? 

If you open the tub of your protein powder and you begin to observe a rancid smell coming out of it or a smell that’s different than usual, that’s the biggest sign of protein degradation. Other signs include:

  • Discolouration 
  • Powder aggregation or clumping 
  • Poor dissolution of powder in a liquid 
  • Bad or changed taste
  • Signs of moisture penetration

These are basic signs indicating that you should throw out your protein powder and get a new one. Consuming such a product can cause some side effects like nausea, vomiting, diarrhoea, stomach pain, etc. 

If your protein powder does not have any of the above-mentioned issues and it smells and tastes just fine, it’s considered safe to take. However, it’s still best to finish your powder before it goes bad and replace it if it has expired. 

What to do if you have accidentally consumed expired protein powder?

If you have accidentally consumed expired protein powder and you feel unusual, please seek medical attention. The most common side effects would be gastrointestinal in origin, as taking an expired product can upset your stomach. Anything serious or life-threatening is not commonly expected.

However, people are different and they are exposed to different factors affecting their health. This is why it’s best to seek immediate medical attention if you feel unwell after taking expired protein powder. 

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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. Available from: