How Long Do Protein Powders Last After Opened?

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When it comes to building muscles or gaining/losing weight, nothing can be as effective as protein powders! They are incredibly beneficial and convenient sources of protein.

However, people often wonder when do they expire once opened. If you too have the same question, then we will help you out!

In this article, we are going to tell you when do protein powders go bad once opened, how to identify if your protein powder has expired as well as how to store it properly.


Protein Powders: A Brief Description

Protein Powders

Protein powders are either extracted from milk (whey) or plants (soy, pea, etc.). People mainly consume them to gain weight, muscles and meet their protein needs.

However, not all protein supplements are fit for consumption, since many a time; manufacturers add chemicals and preservatives into them to extend their shelf life.


When Do Protein Powders Go Bad After Opening?

The majority of the commercial protein powders contain additives like maltodextrin and lecithin, etc., which can increase their shelf life for up to 2 years.

Nevertheless, some brands mention a “best by” date on their protein powders. So it’s up to them to determine when their supplements will expire. However, we advise you to practice caution while shopping for protein supplements! Always examine the list of ingredients on the tub/packet of a protein powder.

Usually, a good quality protein powder has a small list of ingredients as it doesn’t contain preservatives, thickeners, and artificial colorings and flavors. The longer the list of ingredients, the lower the quality of the product.


Let’s have a lo  ok at the shelf life of protein powders depending upon their types:

1. Milk Protein Powders

According to National Bulk Handling Corporation (NBHC), most milk protein powders in the market, such as whey, come with a shelf life of 8 months to 1.6 years when stored in a cool, dry place. Furthermore, many of them contain added preservatives that can extend their shelf life for up to 2 years.

Moreover, when it comes to open whey or casein protein, it can last for 3-6 months even after its best-before date. This is because bacteria and moisture can get into opened packets/containers.


2. Plant-Based Protein Powders

Unlike whey or casein protein, plant proteins like soy, pea, etc., don’t contain milk. This reduces the risk of any bacterial or fungal growth. Thus, plant protein powders have a relatively long shelf life (around 2 years) than milk protein powders. Similarly, open plant proteins can last for 8-12 after their expiry or ‘best-before date.


How To Identify If Your Protein Powder Has Gone Bad?

Here are 4 simple ways of identifying whether your protein powder has gone bad:

1. Sniff It

Sniffing Protein Powder

One of the best ways to find out if your protein has gone bad is by sniffing it. If you sense that it has a foul/sour odor, then, know that it’s time to dispose of it.


2. Check Its Colour

Protein Powder Color

Now, this is something tricky! Manufacturers often mix bleaching agents in their protein powders to make them look “appealing.”  However, natural protein powders are typically light brown/yellow in color. So if you notice any colour changes in your protein powder, it could be a sign that it has gone bad.


3. Look At Its Texture

Protein Powder Texture


Another way to determine if your protein powder has gone bad is to look at its texture. If you notice any wet lumps, it is likely to be spoilt since lumps occur when there is humidity or mold growth in a protein powder.


4. Taste It

Protein Powder Taste

Lastly, if you can’t find out whether your protein powder has gone bad even after smelling it and examining its colour and texture, then taste it. Since protein supplements come in different flavors nowadays, a slight change in their taste or a bitter taste indicates that they have expired.


How To Store Protein Powders?

Protein powders, like other foods, can go bad before their expiry date, if not stored properly. They are best stored in cold, dry, and dark conditions. According to a study, an amino acid lysine in whey protein decreased when it was stored at 35°C for a duration of 1 year.

Another study found out that when whey protein was stored at 45°C for almost 15 weeks, there was an increase in oxidation, which declined its quality.

For best results, store your protein powder in a cool, dark, and dry environment like your pantry or kitchen cabinet. Once you open it, always store it in an airtight container to prevent moisture, dirt, and bacteria from reaching it.

Moreover, most protein powders usually come in plastic tubs that are easy to open and seal. Also, if your whey protein comes in a packet, then it would be better if you transfer it in a tight container/box.


Can Expired Protein Powder Make You Sick?

Although the consumption of expired protein powders doesn’t pose any serious health risk, their protein content can decline over time and reduce their nutritional value.

The science behind this is simple: the amino acid lysine in protein powders tends to react with the sugars and breaks down over time. Therefore, since lysine helps in building muscles, a protein supplement with little or no lysine will not be very effective.



1. Can I store my protein supplement in the refrigerator/freezer?

We recommend you not to store your protein powder in the refrigerator/freezer as it may go bad before its expiry date. The reason behind this is that the sudden change in temperature from hot to cold can cause condensation and spoil your protein powder.


2. When do protein beverages go bad?

If you choose to drink your favorite protein powder instead of eating it, you should be extra careful! It will be best if you drink it within 48 hours as heat and humidity can lead to bacterial growth in your protein powder.


You May Also Like To Read:

How Long Does Casein Last?

The Best Soy Protein Powder In India

Best Protein Bars In India



In a nutshell, the shelf life of opened/unsealed protein supplements depends upon their type, preservatives they contain, and the conditions in which they are stored.

Although consuming expired protein powders doesn’t pose any serious health risks, they certainly lack in their protein content, making them less effective. So make sure you store your protein powder properly to keep it fresh for longer.

If you have any other doubts or queries, please feel free to type them in the comment section!

1 thought on “How Long Do Protein Powders Last After Opened?”

  1. I bought isopure isolate in Aug-23 and consumed for 15 days . Its expiration date is 1 feb-25..l can I consume that protien as of now or i need to buy new one


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