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Can I leave protein shake in fridge?

Protein shakes have become a popular dietary supplement for people looking to build muscle and strength. They provide a convenient way to get a concentrated dose of protein that can help facilitate muscle protein synthesis after exercise. However, there are some questions regarding how long you can safely store protein shakes in the refrigerator.

How long do protein shakes last in the fridge?

In general, commercially made pre-mixed protein shakes like Ready-to-Drink (RTD) shakes or shakes made from a powder mix can be safely stored in the fridge for 3-5 days. Here are some guidelines on fridge life for different types of protein shakes:

Type of Protein Shake Fridge Life
Ready-to-Drink Liquid Shakes 3-5 days
Shakes made from powder mixes 3-5 days
Homemade shakes with milk or yogurt 2-3 days max
Homemade shakes made with just water 3-5 days

The shelf life depends on the specific ingredients in the shake. Shakes containing milk, yogurt or fresh fruit will spoil faster. RTD shakes and powder mixes last a bit longer since they contain preservatives and emulsifiers to help maintain stability.

How to tell if protein shake has gone bad

Here are some signs that indicate your protein shake may have spoiled and should be discarded:

  • Change in consistency – Becomes very thick and clumpy
  • Change in color – Turns brown or gray, fading from original color
  • Separation – Liquid separates from solids
  • Off smells – Sour, rancid or rotten odor
  • Off tastes – Sour, bitter, moldy taste
  • Gas bubbles – Bubbles or foaming appear
  • Mold – Visible mold spots or fuzziness

If you notice any of these warning signs, it’s best to throw out the shake. Consuming spoiled protein can potentially lead to foodborne illness.

Tips to extend fridge life of protein shakes

Here are some tips to keep your protein shakes fresher for longer:

  • Store in airtight containers – This prevents oxygen exposure which accelerates spoilage.
  • Don’t mix in extras – Only mix in ingredients like fruit, greens, nut butters right before drinking.
  • Refrigerate after making – Don’t leave at room temp more than 2 hours before chilling.
  • Check for expiration dates – Don’t use any powder or RTD shakes past expiration.
  • Keep fridge cold – Store shakes at 40°F or below.
  • Use clean utensils – Use clean spoons and shakers to prevent bacteria contamination.
  • Consume quickly – Drink shakes within 3-5 days for best quality.

Can you freeze protein shakes?

Freezing is an option for extending the shelf life of protein shakes. Here are some freezing guidelines:

  • Commercially made RTD shakes freeze well for 2-3 months.
  • Homemade shakes with milk or yogurt don’t freeze well due to texture changes.
  • Shakes made with just water and powders can be frozen for up to 6 months.
  • Store shakes in airtight containers or bags when freezing.
  • Thaw in the refrigerator before drinking.
  • Avoid freezing and thawing shakes multiple times as this can degrade protein quality.
  • Give shakes a sniff and taste test once thawed before consuming.

Reasons protein shakes can go bad

There are a few main reasons protein shakes can spoil, even when kept refrigerated:

  • Bacteria growth – Protein is vulnerable to bacteria like E. coli, Salmonella, Listeria or Staphylococcus aureus. Improper storage temps, unclean utensils or expired ingredients can all contribute to bacteria overgrowth.
  • Oxidation – Exposure to air and light leads to oxidation, causing rancidity. This is why shakes stored in opaque, airtight containers resist spoilage better.
  • Enzyme action – Natural enzymes like proteases in the shake ingredients break down proteins over time, leading to structural and flavor changes.
  • Moisture loss – Dehydration causes powders to clump and alters the texture. Using airtight containers helps maintain moisture levels.

Is it dangerous to drink spoiled protein shakes?

Consuming spoiled protein shakes can potentially make you sick. Here are some of the risks:

  • Food poisoning – From bacteria like Salmonella, E. coli, Staph which can multiply to dangerous levels in spoiled shakes.
  • Nausea, vomiting, diarrhea – Common symptoms of foodborne illness caused by bacteria or mold toxins.
  • Allergic reaction – Mold growth can lead to allergic responses in sensitive individuals.
  • Toxicity – Tyrosine, histidine and tryptophan in degraded proteins can convert to toxic compounds.
  • Digestive issues – Hard to digest proteins and peptides in spoiled shakes may lead to gas, bloating, constipation.

In healthy adults, drinking a spoiled shake likely won’t cause major illness. But those with compromised immunity should use extra caution and not consume shakes with any signs of spoilage.

How to clean protein shake containers

To help avoid bacteria buildup, be sure to wash protein shake containers thoroughly after each use:

  • Rinse with hot water immediately after finishing shake.
  • Wash with hot, soapy water. Dish soap helps break down milk proteins that can stick to bottles.
  • Scrub bottles with a bottle brush to reach inside corners.
  • Rinse bottles thoroughly to eliminate all soap residue.
  • Consider sanitizing periodically with diluted bleach solution.
  • Air dry bottles completely before refilling to prevent mold growth.
  • Avoid reusing bottles that previously held spoiled shakes. Toss them out to be safe.

Taking these steps helps remove lingering bacteria and prevents cross-contamination between shakes.


Can you drink protein shakes after they expire?

It’s not recommended to consume protein shakes past the expiration date printed on the package. While they may seem normal right after expiration, protein quality slowly degrades over time. Old shakes are more likely to cause digestive upset.

Do protein shakes need to be refrigerated before opening?

Most ready-to-drink protein shakes do not require refrigeration until after opening. However, check the label instructions to be sure. Some dairy-based shakes may need fridge storage even when unopened.

Can you put whey protein in the fridge?

Yes, storing whey protein powder in the refrigerator is perfectly fine and can help extend its shelf life. The cold environment slows down oxidation and enzyme activity. Just be sure to bring it to room temperature before using for better mixing.

Do protein shakes go bad if not refrigerated after opening?

Once opened, protein shakes will spoil much faster if left unrefrigerated. Bacteria thrive at room temperature and can multiply to unsafe levels within several hours. Refrigerate or freeze opened shakes for longest quality.

Can bad protein powder make you sick?

Consuming protein powder past its expiration or that shows signs of spoilage can potentially make you sick. Degraded proteins and bacteria buildup can lead to nausea, diarrhea, headaches and other symptoms.

The bottom line

With proper storage, most protein shakes will remain fresh for 3-5 days when refrigerated. Check for changes in smell, taste, texture and appearance to determine if shakes have spoiled. Discard shakes at the first signs of spoilage to avoid getting sick. Follow good hygiene practices, use airtight containers and don’t mix in fresh ingredients too far in advance to get the most out of your protein shakes.