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5 surprising benefits of whey protein powder

Written by John Davis

Last updated: April 11, 2023

Whey protein is the king of protein powders: it’s widely available, incredibly effective, and supported by huge swaths of scientific research.

Though whey protein has a reputation of being for athletes and bodybuilders, our research team found out that its applications go far beyond just peak performance and peak physique. Whey can be useful for weight loss and healthy aging, too.

To find out how, read on for the most important takeaways on the scientific research into whey protein’s benefits.

Whey protein benefits

1. Whey protein provides a complete amino acid profile

You’ve probably heard proteins are the building blocks of our bodies; it’s needed to make everything from molecules, enzymes and hormones to tendons, skin, organs, and muscle tissue.

The building blocks of proteins are amino acids. Our bodies make some of these amino acids, but the ones we can’t make, called essential amino acids, must come from food.

Some foods have only some of the essential amino acids, but whey powder has all of them, which makes it a superior choice for protein needs (1, 2, 3).

2. Whey powder is rich in BCAAs

BCAAs, aka branched chain amino acids, are vital for muscle growth and repair (4). Leucine, one of the BCAAs, is vital for promoting growth, and it also increase levels of glutathione, the powerful antioxidant made in cells (5).

3. Whey protein can increase muscle mass

By far the most common use of whey protein is by body builders and athletes, but it can help anyone build muscle and increase strength.

Because it’s so absorbed so quickly, it can be used as a protein source much faster than other types (6). Whey protein stimulates muscle protein synthesis; leucine works at a genetic and molecular level (7).

Whey protein stimulates the production of more muscle than soy protein (8) and casein protein, thanks to its rapid absorption (9, 10).

4. Whey protein can help you lose weight

Protein is not usually considered as a weight loss supplement, but whey protein exerts some significant effects on excess body fat when used as part of weight loss program.

This was demonstrated in a randomized controlled trial published in 2008 in the journal Nutrition & Metabolism (11). The study had two groups of subjects, both of which were randomly assigned and both of which completed a weight loss program.

One group additionally took a whey protein supplement during the weight loss program, while the other group took a placebo beverage that included the same amount of calories.

Since both groups reduced their caloric intake by 500 calories per day, they both lost weight, but the researchers were able to show that the group that was taking the whey protein drink lost more fat mass, and preserved more lean body mass. Results like these show that the number on the scale is only part of the story with weight loss.

5. Whey protein can help older adults retain strength into old age

Think lifting weights and taking protein is just for people in the prime of their life? Think again. Research shows that even elderly people can benefit from taking weight protein in conjunction with strength training (12).

This combination boosts strength and decreases inflammation, leading to healthier aging.

Whey protein side effects

Since whey protein is derived naturally from dairy, it is extremely safe. The only people who might experience acute side effects from whey protein powder are people who have a dairy allergy, which could potentially be triggered by some of the molecules in whey protein.

Whey protein powder is low in lactose, but it is not entirely free from lactose, according to the Whey Protein Institute (13).

Avoid whey protein if you have a dairy allergy or severe lactose intolerance. If even small amounts of lactose are a problem for you, or if you have a dairy allergy, you should consider one of the many types of vegan protein powders, like hemp protein or pea protein.

Very high protein consumption can inhibit calcium absorption. Another potential side effect of very large protein consumption for long periods of time is inhibition of calcium levels (14).

Because protein can increase calcium excretion, high protein diets have been connected with a greater risk of osteoporosis over long periods of time.

However, this is a risk that’s shared across all types of protein, and is not limited to whey protein in particular. Athletes supplementing with the recommended amounts of whey protein powder are very unlikely to experience significant calcium losses.

Very high protein intake is not recommended for people with kidney disease. High intakes of protein are not recommended to people with kidney disease, since the kidneys have to work harder to digest protein compared to other macronutrient sources.

This recommendation has led to speculation over whether athletes taking high levels of protein could experience a decline in kidney health.

However, even research on healthy bodybuilders who take quite a lot of supplemental protein (nearly three grams per kilogram of body mass per day) has not uncovered any evidence that high levels of protein supplementation carries any risk of negative side effects in the kidneys in healthy athletes (15).

Whey protein dosage

Protein is an easy topic to research, and as a result, nutrition science researchers have come up with very specific recommendations for protein dosing for specific applications.

Athletes should aim for 1.2 to 2.0 grams per day per kg of body weight. For endurance athletes, the current recommendations are 1.2 to 1.4 grams of protein per kg of body weight per day, while for strength athletes, protein intake should be at least 1.6 and potentially up to 2.0 grams per kg of body weight per day (15, 16).

These guidelines are not without their critics, however, and it should be noted that many bodybuilders elect to take up to 2.8 grams of protein per kg of body fat per day, without any apparent problems.

For weight loss, take up to 50 grams per day (regardless of your body size). In contrast, when using protein for weight loss, the optimal amount seems to be around 50 grams, regardless of body size.

This is based on weight loss research which has found that supplementation with this amount of whey protein powder can generate thermogenesis and increase the amount of weight lost, especially when compared to isocaloric supplements (e.g. a carb-based drink with an equivalent amount of calories).

Whey protein benefits FAQ

Q: What does whey protein do for your body?

A: Whey protein delivers the amino acids that your body needs to rebuild and maintain muscle tissue. That’s why it’s so popular among weight lifters and bodybuilders, not to mention athletes of all types.

Q: How does whey protein help you lose weight?

A: Whey protein helps keep your overall calorie intake lower, while delivering the protein your body needs to maintain muscle mass even as you drop fat mass.

The amino acids in protein require more energy expenditure by your body to break down, so they have a mild thermogenic effect compared to other types of macronutrients.

That, combined with the fact that whey protein increases your feelings of fullness (satiety), make it well-suited for weight loss, and you’ll find whey protein as the main ingredient in many meal replacement shakes.

Q: Is whey protein powder good for you?

A: Whey protein powder is a great source of amino acids and highly pure protein without much in the way of carbs or fat. If your protein needs are high, as they are for most athletes, whey protein powder is a good way to fulfill these needs.

Whey protein has even been studied as a way to help older adults with low muscle mass improve their strength and body composition, so don’t think that only athletes can benefit from whey protein powder.

Whey protein is also good for weight loss, because it provides your body with protein without extraneous calories. So, whey protein is beneficial on both fronts: athletes who are looking to add muscle mass, and people who are overweight or obese and want to drop body fat while preserving muscle mass.

Q: Is it safe to use whey protein powder?

A: For most people, whey protein is very safe to use. Even at the very high doses used by bodybuilders, whey protein is not associated with any negative health effects.

There are only two categories of people who should not use whey protein, and these are people who have dairy allergies or serious lactose intolerance, and people who have kidney disease. Since whey is derived from dairy, it makes sense that it could cause problems for people with a dairy allergy or an inability to process lactose in their body.

With regards to kidney problems, high levels of protein intake can stress the kidneys more than a low protein diet. This is not a problem for healthy people (as mentioned earlier, studies on bodybuilders find that their kidneys are perfectly healthy even with very high protein supplementation levels), but if you have renal disease, doctors recommend you limit your dietary protein intake.

Q: What are the dangers of using whey protein?

A: Since it’s naturally derived from dairy, whey protein is quite safe. Unless you have severe lactose intolerance, a dairy allergy, or pre-existing kidney disease, whey protein poses no danger, even when taken at very high levels.

Some bodybuilders take up to three grams of whey protein per kilogram of body mass per day, but even intakes at this high magnitude have no detectable negative effects on, for example, kidney function.

In terms of safety versus efficacy, whey protein is one of the most desirable supplements out there, because it is both very effective and extremely safe.

Related: Our best whey protein powder picks


Whey protein powder is the most popular form of supplemental protein for a reason. It’s got a complete amino acid profile, gets absorbed rapidly into your body, and has a huge body of evidence proving its value for everything from weight loss to athletic performance to gaining muscle mass.

Moreover, it’s not just for serious athletes–regular people looking to lose weight, and older adults looking to fight aging-related loss of muscle mass, can also benefit from whey protein too.


John Davis

John Davis is a Minneapolis-based health and fitness writer with over 7 years of experience researching the science of high performance athletics, long-term health, nutrition, and wellness. As a trained scientist, he digs deep into the medical, nutritional, and epidemiological literature to uncover the keys to healthy living through better nutrition.