Whey protein is a food supplement commonly used along with resistance training to help boost muscle growth and prevent muscle loss. In addition to the performance benefits, protein is also useful in healing wounds and reducing inflammation.
Whey protein is one of the two proteins found in milk. The other is casein. Whey protein has a high bioavailability, meaning it easily absorbs protein. It contains all nine essential amino acids and is one of the richest sources of leucine, an essential branched-chain amino acid that plays a role in muscle protein synthesis.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Benefits of Whey Protein
Whey protein contains all nine essential amino acids (the building blocks of protein).
The body cannot make, produce, or manufacture essential amino acids. Therefore, you must get essential amino acids through food. Amino acids are found in every cell and tissue in our body and are important in the growth, building, and repairing of tissue, including muscle.
Amino acids also serve as building blocks of enzymes, antibodies, and hormones. Adequate protein intake is important for several functions in the body—from cell signaling (the transmitting of chemical signals between cells) to structure to messaging to storage, and more.
Whey protein has been studied for its role in muscle building and muscle loss prevention, wound healing, inflammation, and more.
Supplement Facts
- Active ingredient(s): Whey protein
- Alternate name(s): Whey protein concentrate (WPC), whey protein isolate (WPI), whey protein hydrolystate (WPH), milk protein isolate, bovine whey protein
- Legal status:Generally recognized as safe (GRAS) in 2000 by the FDA
- Suggested dose: Usually around 20 to 40 grams per serving
- Safety considerations: People with milk allergies, kidney disease, and those who are pregnant or breastfeeding should consult with a medical professional before supplementing.
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
Muscle Building and Prevention of Muscle Loss
The muscle-building effects of whey protein occur more when supplementation is combined with resistance training. Researchers suggest that these effects are attributed to the ability to digest whey faster and its high leucine content.
In an analysis of many studies, researchers collected data from 680 people aged 19 to 72 and evaluated the use of different types of protein supplementation, including whey. They concluded that protein supplementation increased muscle mass and strength during prolonged resistance training exercises in both younger and older individuals in the study.
Supplementing with whey protein may be important in the prevention of muscle loss in older adults.
One 2018 study compared the effects of exercise alone, exercise plus whey protein supplementation, or whey protein supplementation alone on skeletal muscle mass and physical function in 81 females aged 65 to 80.
It was determined that the increase in muscle mass was significantly higher in people in the exercise plus whey protein group as opposed to the protein-only group.
Results also revealed that grip strength and speed of gait (how you walk) were significantly greater for people in the exercise and protein supplementation group than for the protein supplementation-only group.
Although this study is promising, it only examined a select population, and other variables can affect the body's ability to gain muscle and prevent muscle loss.
Timing and dosing of supplements, genetics, overall nutrition, and protein quality, as well as types of training, can also play a role in muscle growth and preventing muscle mass loss.
Wound Healing
Protein is an essential nutrient in wound healing. Whey protein contains high levels of amino acids and branch-chained amino acids, which help heal bones, skin, and muscle tissue. These include:
- Arginine
- Glycine
- Leucine
- Isoleucine
- Valine
A higher protein intake is needed for wound healing. For people who do not get enough protein, supplementation may be necessary.
However, much of the research has been in animal studies. Therefore, even though protein is essential for wound healing, it's difficult to say if whey protein is superior to other forms. More studies on humans are needed.
Why Protein Is So Important for Weight Loss
May Reduce Inflammation
Oxidative stress and inflammation are two factors that can increase the risk of disease, including stroke.
Whey protein contains both anti-inflammatory and antioxidative properties. Researchers examined whey protein supplementation's ability to reduce biomarkers in people who have experienced a stroke.
Forty-two people with first-episode acute stroke were included in a clinical study. The intervention group received 20 grams (g) of their daily protein from whey protein. Both groups received 1.5 grams per kilogram of weight (g/kg) of protein from the hospital per day.
After three weeks, researchers found that those receiving whey protein had lower levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP), all of which are inflammatory markers. However, there were no significant changes in other types of inflammatory markers.
While the results are promising, researchers concluded that studies with larger sample sizes and of longer duration of interventions are needed.
Weight Maintenance and Weight Gain
People who struggle to maintain weight or have difficulty eating may benefit from a protein supplement like whey protein.
Drinking requires less effort than eating. Whey protein can be mixed with high-calorie liquids to assist people in meeting their calorie and protein goals.
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Side Effects of Whey Protein
Potential side effects include gastrointestinal symptoms (bloating, cramping, diarrhea), especially in people who are lactose intolerant.
Acne is another side effect reported in those who use whey protein regularly. However, this is likely to be more of an individual response as opposed to a generalized response.
Precautions
Do not start whey protein use if you have kidney or liver disease without talking to your healthcare provider. Long-term, unsupervised supplementation can lead to further damage. In addition, if you have a milk protein allergy, you should not use whey protein.
People who have maple syrup urine disease may also need to avoid whey protein as it contains certain amino acids that they cannot break down.
Dosage: How Much Whey Protein Should I Take?
Always speak with a healthcare provider before taking any supplement to ensure that the supplement and dosage are appropriate for your individual needs.
The amount of whey protein you should take will depend on your health and nutrition goals.
For example, the International Society of Sports Nutrition recommends that athletes looking to increase muscle protein synthesis (depending on age and resistance exercise) consume around 0.25 g of high-quality protein per kg of body weight or an absolute dose of 20 to 40 g of protein per serving.
Whey protein content will vary based on the type, form, and brand you purchase. Variations in ingredients and flavors can also impact nutrition.
The amount of protein can vary depending on the brand and the serving size. A serving size (typically measured in scoops if you are using a powder) can contain anywhere from 13 to 20 g of protein per serving.
What Happens If I Take Too Much Whey Protein?
More isn't always better. There is controversy surrounding how much protein your body can utilize in a single meal. Some research suggests you can use around 20 to 25 g per meal, whereas other research suggests an absolute dose 0.55 g/kg of body weight per meal or 40 g as the maximum.
To determine your exact protein needs, working with a registered dietitian can help you to create an individualized meal plan that aligns with your health and nutrition goals.
Are Protein Shakes Good for Weight Loss?
Interactions
Whey protein might interact with the following medications:
- Levodopa (affects the central nervous system)
- Antibiotics (kill bacteria)
- Bisphosphonates (treat osteoporosis)
How to Store Whey Protein
Store protein powder according to package instructions in a cool, dry place free of sunlight and moisture. Keep the lid tightly closed.
Some companies may list a best-buy date. If they do not, whey protein stored under normal conditions should last around 12 to 19 months.
Sources and What to Look For
In whole food form, whey protein is found in milk, which consists of 80% casein and 20% whey, and is a large contributor to daily protein intake among those who consume dairy products.
When it is manufactured and processed, whey protein comes in several different forms, including:
- Whey protein isolate
- Whey protein concentrate
- Hydrolyzed whey protein
- Whey permeate
Whey Protein Isolate (WPI)
This type of whey protein is the most processed form; it contains lower levels of fat, carbohydrates, and lactose, and higher levels of protein. Whey protein isolate contains 90% or more protein.
Whey Protein Concentrate
Whey protein concentrate undergoes less processing and contains more carbohydrates and fat than whey protein isolate. This type of whey protein is usually more affordable.
Hydrolyzed Whey Protein (Whey Protein Hydrolysates)
This type of whey protein has been treated with enzymes to break down the protein to make it easier to digest. Hydrolyzed whey protein is commonly used in infant formulas, sports drinks, and protein supplements.
Whey Permeate (Dairy Product Solids, Deproteinized Whey, or Modified Whey)
Whey permeate is a coproduct of the production of WPC, WPI, ultra-filtered milk, or milk protein isolate. It is commonly found in bakery products, instant soups, and milk-based drinks.
Always read nutrition labels to ensure that the ingredients in your supplement align with your health goals. Some types of whey protein powders contain added flavors, sugar or nonnutritive sweeteners, and other additives.
When purchasing supplements, it is best to choose those that are third-party certified. Third-party certification like NSF, USP, and ConsumerLab.com certifies supplement quality. It verifies that what the supplement label says is in it is, in fact, in it.
Similar Supplements
There are many different types of protein powder available for purchase. If you are unable to consume whey protein because of allergies or because you choose to avoid animal products, nondairy protein powders may come from sources such as peas, eggs, pumpkin seeds, or hemp, to name a few.
Summary
Whey protein is a common protein supplement that has been studied for its use in muscle building and preventing muscle loss. It has a high bioavailability and contains all nine essential amino acids.
While eating a variety of protein-rich foods is enough for most people to meet their nutrient needs, consuming a supplement can be beneficial when your protein needs are higher or when you cannot consume adequate amounts of protein through food.
Remember that the timing and dosage of whey protein supplementation will vary based on why you are using it. Consult with a registered dietitian for individualized nutrition advice.
Frequently Asked Questions
Is it safe to take whey protein everyday?
Although whey protein supplementation can be helpful in some cases, it should not replace whole, protein-rich foods in your diet. For those who meet their protein needs through diet, a supplement is often not necessary.
In addition, some types of whey protein contain sugar alcohols and other nonnutritive sweeteners that may cause an upset stomach if you are sensitive to them.
The Recommended Dietary Allowance of protein for a healthy adult with minimal physical activity is 0.8 g/kg of body weight, which most people can consume through diet.
For athletes and individuals with higher protein needs, long-term protein consumption at 2 g/kg of body weight per day is safe for healthy adults. The tolerable upper limit is 3.5 g/kg of body weight per day.
However, chronic high protein intake (more than 2 g/kg of body weight per day for adults) may result in digestive, kidney, and vascular abnormalities and should be avoided.
Always discuss your individual needs with a healthcare provider.
Does whey protein affect cholesterol levels?
The studies on whey protein and its impact on cholesterol levels are controversial.
One meta-analysis examined 22 studies evaluating the effect of whey protein on cholesterol. In two studies, the results showed a significant decrease in low-density lipoprotein (LDL) cholesterol (bad cholesterol). However, LDL cholesterol was not affected in 11 other studies.
Additionally, one study demonstrated a significant increase in high-density lipoprotein (HDL) cholesterol (good cholesterol), whereas 12 studies showed that it was unaffected. HDL cholesterol decreased in one study.
However, dosages, types of whey protein used, the length of studies, and study populations have varied widely.
How do I know which type of whey protein is right for me?
To discover what type of whey protein is right for you, you'll need to decide your priorities.
For example, some people use whey protein post-workout to assist in muscle building. They may want a product containing the highest percentage of protein. In this case, whey protein isolate is the better choice.
If you are concerned with getting extra protein but want to eat what tastes good, choose a whey protein concentrate, which tends to contain a lower protein content and higher amounts of fat and carbohydrates.
Identify your priorities and purpose to find the best whey protein for you. Consider working with a registered dietitian or registered dietitian nutritionist to help you reach your health and nutrition goals.
