Whey Protein Benefits, Side Effects and How to Use - Dr. Axe

Fact Checked

This Dr. Axe content is medically reviewed or fact checked to ensure factually accurate information.

With strict editorial sourcing guidelines, we only link to academic research institutions, reputable media sites and, when research is available, medically peer-reviewed studies. Note that the numbers in parentheses (1, 2, etc.) are clickable links to these studies.

The information in our articles is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

This article is based on scientific evidence, written by experts and fact checked by our trained editorial staff. Note that the numbers in parentheses (1, 2, etc.) are clickable links to medically peer-reviewed studies.

Our team includes licensed nutritionists and dietitians, certified health education specialists, as well as certified strength and conditioning specialists, personal trainers and corrective exercise specialists. Our team aims to be not only thorough with its research, but also objective and unbiased.

The information in our articles is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

Whey Protein Benefits for Building Muscle, Burning Fat & More


Whey protein benefits - Dr. Axe

Whey protein benefits are extensive, including helping to burn fat, build lean muscle, boost your immune system and prevent disease. Whey is so effective because it provides a more absorbable source of high protein than nearly any other type of food or supplement, and it’s easy to digest.

Whey protein is one of the most popular proteins for athletes and bodybuilders because of its muscle-enhancing effects. Not only does it work to build muscle and enhance your body’s composition, but it also speeds up the recovery of broken down and stressed muscles after exercise.

According to research published in the Journal of Food Science, whey protein is one of the highest-quality proteins because of its amino acid content and rapid digestibility. Research indicated that it works quickly to aid your muscles so they can heal, rebuild and grow.

What Is Whey Protein?

There are two types of protein found in milk: whey and casein. Whey is the translucent liquid part of milk that remains after the cheese manufacturing process, after coagulation and curd removal.

There’s about 3.5 grams of protein in 100 milliliters of cow’s milk, of which casein accounts for 80 percent and whey 20 percent of the protein.


Whey has a higher percentage of branched-chain amino acids than casein protein, which allows whey to increase protein synthesis faster than casein. Studies show that whey protein also has greater solubility, and it’s more rapidly digested than casein protein.

The term “whey” refers to a complex substance that is separated from the liquid and made up of a combination of protein, lactose, minerals, immunoglobulins and trace amounts of fat. The protein and some highly bioactive peptides found in whey are what make it a superfood for fat loss and building lean muscle.

You’ll be able to find three main types of whey protein, which are distinguished by the processing method.

  • Whey protein concentrate: This is the best and least processed form of whey protein because it contains low levels of fat and cholesterol and higher levels of bioactive compounds in the form of lactose. Because it’s minimally processed, it retains the health-promoting nutrients that are found naturally in whey. You may even find that whey protein concentrate has a more satisfying flavor than other types of whey protein, which is due to its lactose and fat content.
  • Whey protein isolate: Whey protein isolate undergoes further processing in order to remove most of the carbohydrates and fats that are found in whey protein concentrate. Isolates contain about 90 percent or more protein; the problem with isolates is that the proteins can often be denatured due to manufacturing, making it harder on your digestive tract. The denaturation process involves breaking down protein structures and losing their peptide bonds, thereby reducing the effectiveness of the protein. Whey protein isolate does contain a lower lactose content than concentrates.
  • Whey protein hydrolysate: When whey protein isolate is hydrolyzed, larger proteins are broken down into smaller, digestible pieces. The proteins in hydrolysates can be broken down with heat, enzymes or acids. Hydrolysates are meant to be absorbed more rapidly, and they increase blood insulin levels, which is helpful for athletes who want to grow lean muscle. While whey hydrolysate is known to be less allergenic than whey protein concentrate or whey isolates, it’s by far the most processed type of whey protein and the proteins in it have also been denatured.

Nutrition Facts

According to the U.S. Department of Agriculture, one regular scoop (28 grams) of whey protein powder contains roughly the following:

  • 100 calories
  • 5 grams carbohydrates
  • 20 grams protein
  • 1.5 grams fat
  • 1 gram fiber
  • 94.7 milligrams calcium (9 percent DV)

The constituents of whey protein provide high levels of essential amino acids, including branched-chain amino acids (BCAAs). It is the bioactivity of these proteins that gives whey protein its many beneficial properties.

Cysteine is an amino acid that is amply present in whey protein. It is extremely beneficial because it enhances glutathione levels, an important antioxidant that can help reduce the risk of cancer and diseases caused by oxidative stress.

Research shows that the branched-chain amino acids in whey also play an important role in whey’s health benefits because they promote the maintenance of tissue and prevent muscle breakdown during exercise.

Health Benefits

1. Increases Strength and Builds Muscle

Whey protein is a very efficient way to add protein to your diet without extra calories from carbohydrates or fats. It typically contains 80 percent to 90 percent protein, which provides the body with what it needs to build muscle and strength, while recovering quickly after a workout.

According to research published in the Journal of Food Science mentioned above, whey protein stimulates muscle synthesis to a greater degree than both casein and soy protein products. Researchers noted that adding supplemental protein to your diet can help promote gains in muscle mass — especially when paired with resistance training — maintain muscle mass even during caloric restriction and slow down the natural loss of muscle that occurs as you age.

How much protein do you need per day to build muscle? A 2007 study conducted at Baylor University analyzed the use of supplemental protein and amino acids on 19 males who exercised four times per week. Researchers found that supplementing daily with 20 grams of protein, which was made up of 14 grams of whey and casein protein, and six grams of free amino acids led to greater increases in total body mass, fat-free mass, thigh mass and muscle strength compared to those taking the carbohydrate placebo.

Research also shows that athletes in particular need to increase their protein consumption in order to achieve muscle recovery after hard workouts.

2. Burns Fat

A 2014 meta-analysis published in the Journal of the American College of Nutrition examined the effect of whey protein, with and without resistance exercise, on body weight and body composition. Researchers found that adults supplementing with whey experienced significant decreases in body fat and body weight. The results were even more significant among adults who combined whey protein supplementation with resistance exercise.

A study published in Nutrition and Metabolism evaluated the effect of a specialized whey supplement when taken by participants who reduced their caloric intake by 500 calories per day. Compared to the control group participants who also reduced their caloric intake by 500 calories, both groups lost a significant amount of weight, but the group supplementing with whey lost significantly more body fat (6.1 percent of their body fat mass) and showed a greater preservation of lean muscle.

When trying to figure how to lose weight fast, whey protein is a great protein powder to put into your repertoire.

3. Reduces Cravings

Whey protein seems to affect both ghrelin and leptin, two hormones that help regulate your appetite. Leptin primarily affects energy balance, which helps suppress food intake, while gherlin regulates hunger and plays a role in meal initiation.


These hormones work together to tell your body when it needs to eat. Studies show that in obese patients the circulating levels of leptin are typically increased, whereas ghrelin levels are decreased. Whey helps balance out leptin and gherlin secretion, thereby decreasing hunger cravings and helping you stop overeating.

A 2013 study published in the Mediterranean Journal of Nutrition and Metabolism found that whey protein can help reduce caloric intake as a result of various physiological mechanisms. The amino acid content in whey protein is the main factor that influences satiety, according to researchers.

Plus, whey’s effect on satiety and food intake is mediated by the release of ghrelin and other satiety-inducing hormones. These hormones are released in the gastrointestinal system after protein consumption, which may account for food intake suppression when supplementing with whey protein.

4. Stabilizes Blood Sugar Levels

Research shows that having a whey protein shake right before a meal helps regulate your blood sugar levels and reduce your hunger levels so you eat less. Additionally, whey is able to stabilize blood sugar levels when it’s consumed right before meals with a high glycemic index. It stimulates the production of insulin and prevents dramatic spikes in blood sugar levels.

According to research published in the World Journal of Diabetes, whey protein can be used for the management of diabetes symptoms. It slows gastric emptying, stimulates insulin and gut hormones like incretin, which is released after you eat, and works to decrease blood glucose levels.

Whey protein can also naturally reduce blood sugar levels after meals, especially when it’s consumed a few minutes before a meal.

5. Improves Energy

Whey protein increases glycogen, which is a source of energy during exercise or heavy activity, and it enhances the effect of leptin, a hormone that affects energy balance. Plus, because whey is easily digested and accessed by the body, it is converted into energy quickly and can help naturally boost energy levels.

A 2013 study published in the Journal of Sports Science and Medicine found that females experienced an increase in performance markers when they consumed whey protein after resistance training. Some of the performance markers tested in the female basketball players included agility running, vertical jumping and muscle endurance.

The improved energy levels and performance are due to the amino acids that are present in whey protein. When the body lacks sufficient levels of amino acids, that’s when you experience muscle wasting and delayed exercise recovery after a workout.

6. Boosts Glutathione

Whey protein helps increase the production of glutathione, the master antioxidant that is found in every cell of your body. Research shows that whey protein is rich in cysteine, an amino acid that’s needed for the synthesis of glutathione.

Scientists at Ohio State University found that supplementing with hydrolyzed whey protein isolate increased intracellular glutathione concentrations by 64 percent.

Glutathione helps eliminate free radicals that cause cell damage, cancer and aging diseases, such as Parkinson’s and Alzheimer’s. It also helps protect your body from environmental toxins and drug resistance, and it’s critical for a strong immune system.

7. Boosts Immunity

Because whey protein promotes the synthesis of glutathione, it works to boost your immune system. Glutathione also boosts the efficacy of other antioxidants, like vitamin C, CoQ10, ALA and vitamin E.

Whey protein also contains a number of other proteins and vitamins, such as vitamin D, that positively affect immune function and demonstrate antimicrobial activity.

According to research published in the Journal of the International Society of Sports Nutrition, whey protein helps the body recover after exercise, which is important for avoiding impaired immunity, oxidative stress and excessive inflammation. Not only does whey increase the production of glutathione, but it also contains L-arginine and L-lysine, amino acids that promote immune function.

8. Improves Heart Health

Studies show that whey protein promotes a reduction in blood pressure and arterial stiffness and improves lipid profiles. It works to reduce cardiovascular risk factors by protecting your muscles and helping you lose weight. Reductions in body weight reduce obesity-related problems like heart disease.

A 2016 study published in the American Journal of Clinical Nutrition evaluated the blood pressure of 42 participants who consumed whey protein powder or maltodextrin (the control) for eight weeks. Those who used whey experienced significant reductions in blood pressure and increases in blood circulation. Whey protein also lowered total cholesterol levels.

9. Extends Life Span

Whey protein has been found to increase life span by reducing muscle wasting that’s associated with aging and increasing nutrient absorption without increasing hunger. This is important because, as you age, you lose bone mass, cell function and your digestive function decreases.

However, whey has been shown to reduce the loss in all of these areas, making it an incredible superfood that slows the aging process.

A study conducted in Germany found that when older adults supplemented with whey protein, it caused positive effects on muscle protein synthesis, muscle mass and muscle strength.

A 2016 study published in Nutrients discovered that increased protein intake among the elderly improves muscle health, helps maintain energy balance and weight management, and supports cardiovascular function.

Best Whey Protein

You can easily find whey protein in powder form in most natural food or vitamin stores or online. In order to reap the benefits of whey protein’s constituents, you should choose the best source that’s available.

When purchasing whey protein, opt for whey concentrate that comes from grass-fed cows. Look for a whey protein powder that is natural or organic and is completely free of hormones, pesticides, artificial ingredients, gluten and genetically modified organisms.

You can find A1 or A2 whey protein. A2 beta-casein is the type that has been produced naturally by animals for thousands of years. It’s believed to be easier to digest, and some research suggests it has many fewer side effects on human health than the other type, called A1 casein.

A1 is the “newer type of casein,” first developed sometime in the past few thousand years following animal domestication. It came about after certain genes caused proteins to change, resulting in proline amino acids changing over to histidine.

Today, A1 beta-casein is more abundant in dairy cows that are used to produce the vast majority of milk in the U.S. and even Europe. Ideally, you should opt for A2 whey protein powder.

Avoid any whey protein that is processed, like whey protein isolate. Remember that certain isolates contain denatured proteins that make the supplement less effective.

Plus, cheaper whey protein isolates often contain added artificial sweeteners that can be hard on the digestive system and neurotoxic. Organic whey concentrate from grass-fed cows gives you the largest amount of compounds, like immunoglobulins and minerals, that support many body functions.

How to Use

To use whey protein powder, simply add one scoop (about 28 grams) to roughly eight ounces of a  liquid, like water or unsweetened almond milk. The powder is reconstituted when it’s mixed with a liquid. Using a blender or bottle shaker helps mix the powder and give you a creamy or frothy texture, without the clumps.

For the best experience, make a whey protein smoothie using liquid, fruit (fresh or frozen) and perhaps ice in a high-speed blender. There are many protein shake recipes that can be prepared with whey protein powder. It’s also commonly used for a protein coffee recipe. You can also add whey to oatmeal or yogurt and stir in.

When do you take whey protein? The best times to use whey protein is in the morning, as part of breakfast, as a mid-afternoon snack and after workouts.

Taking one scoop of whey protein about 30 minutes after a workout helps improve muscle recovery. It may also be helpful to take whey protein 30 minutes before a meal. This will help improve satiety and is meant to help you avoid overeating.

Risks and Side Effects

Is it safe to use whey protein? Despite the many health benefits of whey protein, it should not be consumed by people with a milk allergy or lactose intolerance.

What are the dangers of whey protein? If you have a sensitivity to lactose, you may experience gas, bloating, cramps, fatigue, headaches and irritability after consuming whey protein.

Whey products that contain artificial sweeteners, like isolates, may also lead to whey protein side effects because they can be more difficult to break down and can cause digestive discomfort.

If you don’t have a whey allergy, then make sure you use the highest quality whey protein product out there. That makes it easier to digest because it’s less processed and doesn’t contain added artificial ingredients or chemicals.

People who are unable to use whey protein should consider trying a bone broth–based protein powder, collagen protein, or a plant-based protein powder, like pea protein or sprouted brown rice protein powder, instead.

Final Thoughts

  • Whey is the translucent liquid part of milk that remains after the cheese manufacturing process, after coagulation and curd removal. It’s a complex substance that is separated from the liquid and made up of a combination of protein, lactose, minerals, immunoglobulins and trace amounts of fat.
  • The constituents of whey protein provide high levels of essential and branched-chain amino acids. It is the bioactivity of these proteins that gives whey protein its many beneficial properties.
  • Is whey protein powder good for you? There are many benefits of this type of protein powder, including its ability to increase strength, build muscles, burn fat, reduce cravings, stabilize blood sugar levels, improve energy, boost glutathione levels and immunity, and extend life span.
  • What’s the right whey protein dosage? Taking one scoop (about 28 grams) 30 minutes after workouts or 30 minutes before meals can be beneficial.
  • Look for a whey protein powder that is natural or organic and is completely free of hormones, pesticides, artificial ingredients, gluten and genetically modified organisms. Also, avoid any whey protein that is processed, like whey protein isolate.

More Nutrition