How long do proteins last? - times after standby, open and expired

How long do proteins last? - times after standby, open and expired

How long do proteins last? - times after standby, open and expired
How long do proteins last? - times after standby, open and expired

The use of protein shakes is increasingly common, both for weight loss and to increase muscle mass. They are practical, efficient and time-saving.

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

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

What are protein shakes?

What are protein shakes?

Protein shakes are one of the most popular sports supplements. They can be used both for weight loss and for gaining muscle mass.

Most protein shakes consist of purified cow's milk whey protein (  casein  ), fats and carbohydrates in smaller amounts.

There are various  myths about protein  : that it is not a healthy supplement, that it makes you fat and that over time it 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 muscle production.

And while protein should not be taken as a way to replace nutrition. When you exercise intensively on a regular basis, protein shakes serve to improve muscle recovery.

How long does a protein last?

Like almost all products on the market, whey protein has a shelf life on the label. This date is usually quite long, 12 to 18 months after the date of manufacture, or even longer.

It is not recommended to consume them after this date. However, it is true that if they have been stored well, they can last longer after the expiration date - in this case, up to approximately another 1 month, they are considered safe.

As for open whey protein, it should last at least 3-6 months after the expiration date. The reason for this is that opening the package increases the possibility of dust accumulating bacteria or moisture. As long as the water does not turn into dust, it must be safe for consumption.

As for the shake after cooking, determining   exactly   how long the protein shake lasts   is more complicated, as there may be several factors.

As a general rule, it can be said that protein shakes should be taken no   more than 1-2 hours after preparation  .

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

In general, these microorganisms can grow at twice the rate every 20 minutes, which can be really dangerous to your health. To get an idea, a bacterium can multiply by 2 million in 7 hours. (1)

If you drink a shake more than 1-2 hours after its preparation, it is likely to have a high content of bacteria in it and this can cause damage to your body.

Other factors to keep in mind to avoid protein shake poisoning:

  • Temperature. The ideal conditions for the growth of the bacterium are 37 ° C-38 ° C. Temperatures close to this temperature will significantly reduce the time of the protein shake.
  • Cleaning  . If the shaker or container in which you usually make your protein shake is not completely clean, the chances of poisoning increase.
  • Water quality. Water quality is important to determine how long a protein shake lasts. The use of tap water or spoiled milk can add additional microorganisms that reduce the duration of the protein shake.
  • Contamination or contact with liquid. Dirty hands or external contaminants can reduce the time it takes to shake after cooking. It is important to ensure that the container in which it is prepared is closed.

Can you make a smoothie at night and take it the next day?

If you decide to make a smoothie at night and take it the next day, be sure to keep it in the refrigerator. You should think of shakes as an analogue of milk.

In common sense, no one remembers 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 to support that the intake of whey protein or other protein supplements in normal amounts is dangerous to health. The key to drinking protein shakes is not to overdo it. Most of the side effects reported are for people with a casein allergy or  lactose intolerance  .

The most common symptoms of protein poisoning are indigestion, diarrhea and acne. Usually caused by a low level of purification in the production process. This is because low-quality protein brands or brands that have exceeded their expiration time may have impurities and suspicious by-products.

Remember that a  bulk diet  for muscle growth does not necessarily mean a life of protein supplements. But make the right balance of macronutrients.


Ideally, drink a protein shake immediately after cooking.

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

Although it is not possible to determine the exact duration of the protein shake after preparation, it is recommended not to exceed more than 1-2 hours at room temperature.

If you decide to make a smoothie the night before, be sure to keep it in the fridge.


  1. Food poisoning - symptoms. Source
  2. 8 food poisoning and contamination. Source
  3. Optimal nutritional gold standard guide. Source
  4. Whey protein. Source