proteins last - Times after ready, open and expired

The use of protein shakes is more and more frequent to lose weight and increase muscle mass. They are practical, effective, and save time.

Various reasons can lead to a person preparing the shake before work or going to the gym and drinking it a few hours later. However, proteins can get nasty, over time can be dangerous.

This article describes how long a protein shake lasts after preparing and opening the package. What is the maximum time to avoid poisoning?

What are protein shakes?

Protein shakes are one of the most popular sports supplements. They can be used both to lose weight and to gain muscle mass.

For the most part, protein shakes are purified cow’s milk, whey protein ( casein ), fats, and carbohydrates in lesser amounts.

There are different myths about proteins: that it is not a health supplement, that it makes you fat, and that over time they can cause damage to the body.

The reality is that the importance of proteins cannot be denied; in fact, they are the raw material for the manufacture of muscles.

And while protein should not be taken as a way to replace meals. When you practice intense exercise regularly, protein shakes improve muscle recovery.

How long does a protein last?

Like almost all products available, whey protein has an expiration date on the label. This date is usually quite long, 12 to 18 months after the production date, or even longer.

After this date, it is not recommended to consume them. However, it is true that if they are stored well, they can last a long time after the expiration date – in this case, approximately up to 1 more month, they are considered safe.

When it comes to open whey protein, it should last at least 3-6 months after the expiration date. This is because opening the package increases the possibility of the dust accumulating bacteria or moisture. As long as the water doesn’t turn to powder, it should be safe to consume.

As for a shake after preparation, determining exactly how long a protein shake lasts is more complex since there can be several factors involved.

As a general rule, it can be said that protein shakes should be taken a  maximum of 1-2 hours after preparation.

Why? Microorganisms can use protein shakes as an energy source to reproduce. If there is no water, they cannot grow; but when there is, they begin to multiply exponentially.

These microorganisms can grow at a double rate every 20 minutes, which can be dangerous for your health. To get an idea, a single bacterium can multiply by 2 million in 7 hours. (1)

If you drink a shake more than 1-2 hours after it has been prepared, it likely has a high content of bacteria, and this can cause damage to your body.

Other factors to consider to avoid protein shake poisoning:

  • Temperature. The ideal conditions for a bacterium to grow are 37 ° C-38 ° C. Temperatures close to this temperature will considerably decrease the time a protein shake lasts.
  • Cleaning . If the shaker or the container where you usually prepare your protein shake is not completely clean, the chances of poisoning multiply.
  • Water quality. To determine how long a protein shake lasts, the quality of the water is essential. Using tap water or spoiled milk can add different microorganisms that decrease the duration of the protein shake.
  • Contamination or contact with the liquid. Dirty hands or external contaminants can reduce the time a shake lasts after preparation. It is essential to ensure that the container is prepared is closed.

Can you prepare a smoothie at night and have it the next day?

Suppose you decide to make a smoothie overnight and have it the next day make sure to keep it refrigerated. It would help if you thought of shakes as a milk analog.

By common sense, no one thinks of drinking a glass of milk left at room temperature the day before; the same thing happens with protein shakes.

Protein Poisoning: Is It Bad To Take Whey Protein?

There is no evidence that taking Whey Protein or other protein supplements in average amounts is dangerous to health. The key when drinking protein shakes is not to go overboard. Most of the reported side effects are for people with a casein allergy or lactose intolerance.

The most common symptoms of protein poisoning are indigestion, diarrhea, and acne. They are generally caused by a low level of purification in the manufacturing process. This is because low-quality protein brands or brands that have exceeded their expiration time may have impurities and questionable secondary ingredients.

We remember that a bulk diet for muscle growth does not necessarily mean living on protein supplements. But make a correct balance of macronutrients.


Ideally, have a protein shake immediately after preparation.

After opening the package, no more than 3-6 months and it is essential to keep it in a dark and closed place.

While determining exactly how long a protein shake lasts after preparation is impossible, it is recommended not to exceed more than 1-2 hours at room temperature.

If you choose to make a smoothie the night before, keep it refrigerated.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *