What Is Whey Protein? (Everything You Need To Know)  

Whey protein is a type of milk protein. In fact, it’s one of the two most abundant types of proteins found in milk [1]:

• Casein (80%)
• Whey (20%)

When we say whey, we’re actually referring to the watery part of milk. For example, the liquid substance you can sometimes see floating when you open a yogurt is whey [2].

This substance is usually extracted from milk during cheesemaking. Then it undergoes processing so that we can get whey proteins from it.

Whey proteins consist of [3]: 

• Beta-lactoglobulin
• Alpha-lactalbumin
• Bovine serum albumin
• Immunoglobulins

Whey is also considered a complete protein because it contains all nine essential amino acids.

There are three main types of whey protein, based on how it’s processed [4]:

• Whey protein isolate: Isolate is at least 90% protein. It contains fewer carbs, fat, and lactose than whey protein concentrate because it goes through more processing.
• Whey protein concentrate: Concentrate is 70 - 80% protein and is usually cheaper than isolate.
• Whey protein hydrolysate: Hydrolysate, or hydrolyzed whey, is the most expensive type of whey protein. It’s pre-digested, which makes it easier to consume.

You’ll find whey protein supplementation that contains all three types of whey.

So, how can you choose the right type for yourself?

In general, we’d say you choose a whey hydrolysate if you have digestion issues.

Otherwise, it’s probably not worth the price because it’s not of higher quality than the other types of whey.

Regarding quality, isolates are better than whey protein concentrates. Although they are a bit more expensive, the price difference is usually negligible. But isolates contain fewer carbs and fats, so they’re more healthy for you overall [5].

Here are some of the many health benefits of whey protein: 

• Promotes weight loss. Whey protein can accelerate weight loss because it boosts metabolism and decreases appetite. So, whey consumers can burn more calories and feel full for longer [6].
• Decreases cholesterol. Cholesterol can cause cardiovascular diseases, so the lower it is, the better. Luckily, one study found that eating 54g of protein per day over 12 weeks reduced both total and LDL cholesterol in overweight individuals [7]. And since whey lowers cholesterol, it may simultaneously decrease the risk of heart problems.
• Builds muscle mass. Taking whey protein will equip your body with the amino acids and protein needed for muscle growth. One of those amino acids is leucine, which stimulates muscle protein synthesis [8].

May reduce the risk of cardiovascular diseases. We’ve already said that whey lowers cholesterol.

That’s one way in which it decreases the risk of heart problems. But it also does so by reducing elevated blood pressure [9], which offers you double protection against cardiovascular issues.

The biggest health risks of whey are related to digestion. It can lead to cramps, gas, bloating, stomach pains, and similar digestion problems.

But this mainly happens when people with lactose intolerance take a whey protein supplement. So, there’s little to no reason to worry about these side effects if you tolerate milk just fine.

However, in rare cases, some individuals might experience other side effects of whey protein supplements, like [10]:

• Nausea
• Headache
• Fatigue
• Reduced appetite
• Acne

Take the right preventive measures to avoid these side effects:

• Don’t take whey protein without working out. If you take protein without being physically active, you risk damaging your liver [11].
• Don’t swap meals with supplements. You should still maintain a healthy and diverse diet even if you start taking supplements. No supplement can replace real food.

Be mindful of your body. For example, you might not know that you’re lactose intolerant. Your first symptoms might occur when you start taking whey protein. That’s why you should be mindful of what your body’s telling you at all times.