Last Updated On January 1, 2026
Being lactose-intolerant means I need to take extra care when deciding what to put in my body post workout.
From my experience with protein powders and supplements, the information provided on packaging can be misleading, especially when it comes to lactose.
I wanted to be certain I was consuming the right ingredients, so I explored this topic further and found that the amount of lactose in whey protein can vary depending on how it is processed.
Some whey protein products are filtered to remove most of it, while others contain higher amounts.
Read on to learn how you can find a protein powder and determine its lactose levels.
- Does Whey Protein Contain Lactose?
- Can Protein Shakes Cause Lactose Intolerance?
- What Are the Symptoms Of Lactose Intolerance?
- How Is Whey Protein Made?
- How To Choose Protein Powder If You’re Lactose Intolerant?
- Common Questions About Whey Protein and Lactose
- So, Can I Take Whey Protein If I'm Lactose Intolerant?
Does Whey Protein Contain Lactose?
Whey protein supplement is a byproduct of cheese production; therefore, it does contain lactose, a type of sugar found in milk and other dairy products.[1]
While it's a great source of protein, whey concentrate powder, the most common form of whey protein, contains around 4-8% lactose.[2] For many, it is the percentage of lactose that the GI tract will certainly "notice."
For those of us with lactose intolerance, there are whey protein products that have lower lactose content or are almost entirely lactose-free.
Removing all traces of lactose is probably impossible, but it is possible to reduce that amount to negligible.
Whey protein isolate and hydrolysate are further processed to remove most lactose. In 99% of cases, isolate and hydrolysate contain well below 1% lactose, making them suitable for people who are lactose intolerant. I typically don't have trouble with whey protein.
Pea, soy, and brown rice protein supplements plus nine essential amino acids could be an excellent dairy-free protein alternative for those who can’t tolerate whey protein. Sometimes, I choose these options first anyways because I enjoy the taste!
Can Protein Shakes Cause Lactose Intolerance?
You don't have to worry about becoming lactose intolerant just because you started consuming whey protein powder. Protein shakes themselves do not cause lactose intolerance. It is a genetic condition that affects the body's ability to break down milk sugar.[3]
Numerous scientists agree that reducing lactose consumption is the best approach for most adults.[4]
Most whey protein powders can unquestionably trigger symptoms or make current symptoms worse.
The two terms many people do not know how to distinguish are intolerance and allergy. Intolerance is significantly different from a cow’s milk allergy, which is an immune system reaction to the allergens in milk.
A protein shake containing whey protein can cause an allergic reaction in individuals with a milk allergy, but this is unrelated to lactose intolerance.
What Are the Symptoms Of Lactose Intolerance?
Lactose intolerance symptoms differ from person to person, leaving some sensitive to lactose and others severely lactose intolerant.
For me, it usually starts with bloating, followed by abdominal pain. Sometimes it leaves me feeling sick and tired for several hours, making it difficult to focus on anything else.
Luckily, bloating and stomach cramps are not accompanied by flatulence and diarrhea, even though these are also frequent symptoms.
I've noticed that the severity of my symptoms depends on how much lactose I consume. I feel perfectly fine if I accidentally consume a small amount of lactose. If I consume more, the symptoms can be much more severe and last longer.
Basically, when you have a low level of an enzyme called lactase, undigested lactose reaches the large intestine, where bacteria break it down, producing hydrogen (gas), lactic acid, and carbon dioxide.
That's why individuals with dairy intolerance usually experience a range of symptoms after consuming lactose-containing foods.
How Is Whey Protein Made?
The technology of whey protein production is complex.
All begins with milk pasteurization, which aims to destroy bacteria present in raw milk. During cheesemaking, the cheese and whey are separated after milk is coagulated with rennet or an acid. Before removing water and other residues, the whey is in a liquid state and has a high protein, lactose, and minerals concentration.
The main difference between types of whey protein powder is the level of processing it undergoes, which can affect its nutritional profile and price. It can be further purified by microfiltration and ultrafiltration processes.
Microfiltration is the process of separating molecules of different masses using membranes of different diameters. Membranes keep the whey protein while the lactose and fats pass through, and we get whey isolate. Ultrafiltration is based on the different charges of the molecules.[5]
Sometimes manufacturers add the enzyme lactase during the production process. The goal is to reduce the lactose content in the final product.
How To Choose Protein Powder If You’re Lactose Intolerant?
Choosing the suitable protein powder is challenging if you're lactose intolerant.
Fortunately, the production of dietary supplements is constantly progressing, so you have more and more protein powder options at your disposal every few months.
Common Questions About Whey Protein and Lactose
No matter how pure whey protein is, no one can guarantee it is lactose-free. After complete processing, it will still contain trace amounts of lactose. For most, it is a negligible amount of lactose, so they can consume whey protein without experiencing any discomfort.
There are several ways to remove lactose from whey protein supplements. The most common method is filtration, where it is passed through a series of filters to remove the lactose.
Additionally, some companies use enzymatic processes to break down lactose into its component parts, glucose, and galactose.[6] You can't do any of this at home, as it is done during the manufacturing process in factories.
You can still gain weight from milk even if you are lactose intolerant. Taking milk while being lactose intolerant will not change the fact you are ingesting proteins, fats, and carbohydrates. Also, that can cause inflammation, affecting your body's ability to absorb nutrients and leading to additional weight gain.
Protein shakes can cause stomach discomfort for several reasons, including lactose intolerance, the type of protein used, the amount of protein consumed, and the ingredients in the shake. Lactose is usually the culprit, but it can also be artificial flavors/sweeteners or excessive amounts, so before you declare yourself lactose intolerant, think about other factors as well.
So, Can I Take Whey Protein If I'm Lactose Intolerant?
You may be able to drink whey protein even if you are lactose intolerant. Isolate whey protein is undoubtedly a better option compared to whey concentrate and whey hydrolysate.
Most people with lactose intolerance like me can digest a small portion of lactose in whey protein isolate.
However, do not despair if you have severe intolerance! You can choose vegan protein powders to boost your protein intake.
References:
- https://examine.com/supplements/whey-protein/
- https://www.usaid.gov/whey-protein-concentrate-commodity-fact-sheet
- https://www.mdpi.com/2072-6643/12/9/2689
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586575/
- https://www.docdroid.net/YaasLzE/dairy-02-00029-pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9632185/
Last Updated on January 1, 2026
