Whey Protein: Potential Benefits, Known Risks, and More
Updated on December 18, 2025
ON THIS PAGE
ON THIS PAGE
Note: The U.S. Food and Drug Administration (FDA) does not approve supplements for safety or effectiveness. Talk to a healthcare professional about whether a supplement is the right fit for your individual health, and about any potential drug interactions or safety concerns.
Whey protein is a widely used supplement that supports muscle growth and post-workout recovery. While it's especially popular among athletes, research suggests it may also aid in blood sugar regulation, weight management, and more. Derived from animal milk (primarily cow milk, commercially), whey protein is generally considered safe, though it may not be suitable for people with dairy allergies, lactose sensitivity, or certain medical conditions.
Read on to learn more about the possible benefits and risks of whey.
Potential Health Benefits of Whey Protein
Whey protein is best known as a workout supplement. Limited research suggests it may have other health perks.
May Boost Muscle Mass and Health
“Protein supplementation, including whey, can promote muscle growth, strength, and recovery when paired with resistance training,” says Morgan Walker, RDN, a sports nutritionist at Lebanon Valley College in Annville, Pennsylvania. A recent review from Italy supports this, though the authors found results vary based on dose, timing, and overall diet.
Walker also notes that whey’s muscle-building effects could be beneficial for older adults. A systematic review in Poland found that pairing whey supplementation with age-appropriate exercise may improve muscle mass. The Italian review reported similar results, highlighting that whey protein supplements helped maintain muscle mass and prevented sarcopenia in older adults, which can ultimately help prevent falls.
May Help Body Composition and Nutrition
Whey protein can be beneficial for those who want to gain more weight. And it can be helpful for people with chronic health conditions, swallowing difficulties, or those who struggle to gain nutrients through food alone.
Whey protein supplementation may also improve body composition (the balance of lean muscle and fat), according to one meta-analysis from Iran, with the greatest benefits seen when combined with resistance training and moderate calorie restriction. The aforementioned Italian review similarly found whey protein helped increase lean body mass for those with nutritional deficiencies or age-related muscle loss, especially when paired with exercise.
A systematic review and meta‐analysis from Egypt of four studies found that whey protein supplementation improved body weight, grip strength, and even reduced the toxicity of chemotherapy for malnourished people with cancer.
May Regulate Blood Sugar Levels
Whey protein might also help regulate blood sugar levels, especially after eating. One small Australian study of 10 males in their mid-twenties found that whey simultaneously boosted sugar output from the liver and sugar uptake by tissues, which helps keep blood glucose in balance.
Larger studies with diverse groups of participants are needed to corroborate these results.
For people with type 2 diabetes, whey protein consumed before meals may help stabilize blood sugar by boosting insulin secretion, slowing gastric emptying, and triggering hormones that regulate appetite, according to a European meta-analysis of five randomized controlled trials, suggesting it may support short-term glycemic control.
May Support Healthy Metabolic Function
One systematic review and meta-analysis from Iran suggested that whey protein supplementation could significantly reduce systolic blood pressure (the top number on a reading) and possibly help with hypertension. The authors noted that some studies were small or only evaluated people with conditions such as high blood pressure or obesity, and more research is needed.
A European meta-analysis found little effect of whey protein on blood pressure, though it did note reductions in LDL (“bad” cholesterol) and total cholesterol.
“This evidence is moderate,” says Walker. “Longer-term studies are still needed to confirm these effects.”
May Support Wound Healing
Whey protein provides essential amino acids to help your body repair skin and tissue after injury. For instance, one Iranian study of 80 ICU patients found that topical whey-protein cream, applied twice daily for two weeks, resulted in less-severe pressure ulcers (bedsores) compared with those patients given a placebo — though more research in broader groups is needed.
Weight Loss Effect of Whey Protein
Whey protein’s effect on weight loss depends on context, Walker notes. “When combined with a calorie-restricted diet, whey protein has been shown to promote modest reductions in body weight and fat mass, while helping preserve lean muscle,” she says.
This matters because preserving muscle ensures that weight loss comes primarily from fat, not lean tissue, Walker adds.
Some short-term studies suggest whey protein may reduce body fat in those who are overweight or have type 2 diabetes mellitus, especially when calories are also restricted. But a recent review from Brazil noted the overall evidence is inconclusive.
It’s also possible to overdo it. Whey protein can contribute to weight gain if it adds more calories than you’re burning, so it works best as part of an overall diet and exercise plan.
Potential Risks and Side Effects of Whey Protein
Whey protein is generally considered safe when consumed in recommended amounts. But it’s not regulated by the U.S. Food and Drug Administration (FDA) and therefore not proven for safety or effectiveness.
Eating too much protein in any form can lead to side effects or interactions.
Risks
Unless you have a milk allergy, whey protein is unlikely to pose a serious health risk. But people with lactose intolerance may experience adverse effects, particularly with whey protein concentrate, which contains more lactose.
Many products also contain added sweeteners and artificial flavors, which don’t add nutritional value. Because the FDA doesn’t regulate these supplements, you risk ingesting contaminants like fillers or heavy metals, so it’s important to choose brands with quality certifications from reputable third parties.
Sugar and artificial sweeteners may contribute to unwanted weight gain and insulin resistance, which can be especially harmful for people with type 2 diabetes or who are overweight.
Whey protein isn’t recommended for pregnant or nursing people, as it’s been linked to a higher risk of gestational diabetes.
If you take any medications, talk to your doctor before using whey protein, as it can change how your body absorbs some medications, including albendazole (for parasitic infections), alendronate (for osteoporosis), and some antibiotics.
Side Effects
Gastrointestinal issues are a common issue with whey protein supplements, particularly if you consume a large amount, including:
Forms of Whey Protein
“Whey protein is commonly available in three forms: concentrate (WPC), isolate (WPI), and hydrolysate (WPH),” says Walker. “Any of the three forms will effectively stimulate muscle protein synthesis, and which is best mostly comes down to factors like cost, lactose content, fat, and how easy it is to digest.”
Whey protein concentrate is widely used in drinks, bars, and infant formula, and is available as a powder. Its protein concentration can range from 20 to 85 percent, depending on the product. Because it contains more lactose and fat than isolate or hydrolysate, protein concentrate may take longer to digest and be less tolerated by people with lactose sensitivity.
Whey isolate is also commonly used in sports drinks, bars, and powder. Because it’s more refined, it’s absorbed and digested quickly. Whey protein isolate contains about 90 to 95 percent protein and is typically lower in lactose and fat than other forms, making it a good choice for people who are lactose-sensitive.
Whey protein hydrolysate is the easiest form to digest and absorb, and it’s a common ingredient of specialized infant formulas. It’s also available in powder form, typically as a post-workout supplement, says Walker.
Food Sources of Whey Protein
Whey supplements may help boost protein intake, but when possible, experts encourage prioritizing whole food protein sources because they provide additional nutrients like vitamins, minerals, and healthy fats.
Whey, found naturally in dairy products, is the liquid portion that separates from curds during cheese-making. Here are a few common whey-rich foods:
- Milk (whole, 1 cup): 14 grams (g) of protein, 20 percent of which is whey
- Yogurt (Greek, plain, whole milk, 100 g): 78 g of protein made up of whey and casein (another milk protein)
- Ricotta cheese (½ cup): 1 g of protein (cheese makers heat whey to make ricotta)
How to Select and Store Whey Protein
If your doctor says you can take whey protein, choose and store it properly to get the most benefit. Keep in mind:
Selection
Whatever type of supplement you choose, it’s important to check the label for approval by USP, NSF, or ConsumerLab.com to make sure it’s third-party tested for quality and purity, says Walker.
Also, consider your sensitivity to lactose. Whey isolates contain less lactose than concentrates, and those with lactose intolerance may be able to digest isolates more easily.
Lastly, “review the ingredient list for minimal added sugars, artificial flavors, or fillers, and consider protein content per serving to make sure it aligns with your goals,” says Walker.
Storage
Whey protein powder can stay fresh for months, but proper storage is key — keep it sealed in a cool, dry place between 68°F and 77°F to maintain quality and prevent clumping.
Dosage of Whey Protein
The general recommended dietary allowance for protein is a minimum of 0.8 g per kilogram (g/kg) of body weight, or roughly 0.36 g per pound, though your ideal intake will depend on your age, health status, and physical activity.
Here’s the breakdown of protein doses for different groups:
Highly active individuals: Protein needs may increase to 1.1 to 1.7 g/kg of body weight for highly active people, with whey protein used to supplement dietary intake accordingly.
Older adults: Higher protein intakes (around 1.2 g/kg per day or more) may help maintain naturally declining muscle mass.
Weight management: Research suggests that higher-protein diets (1.07 to 1.6 g/kg per day) may reduce weight in a healthy way, though long-term studies are needed.
The Takeaway
- Whey protein comes from animal milk and contains all essential amino acids. You can get it naturally through foods like milk, yogurt, and certain cheeses, or buy it as a supplement.
- Research suggests whey protein may aid in building muscles, weight and nutrition management, and wound healing, though more research is needed.
- Most people can safely use whey protein, but those with milk allergies, lactose intolerance, certain medical conditions, or who are pregnant or breastfeeding should talk to a healthcare provider first.
- Speak with your doctor or a registered dietitian before starting a whey protein supplement to determine whether it’s right for your goals.
FAQ
Is whey protein concentrate the same thing as whey protein isolate?
Yes, with differences in protein and fat makeup. While both types are used in nutritional supplements, whey protein isolate typically has a higher percentage of protein content.
Is whey protein safe to use?
Whey protein is considered safe to consume in moderation for most people — large amounts might provide excess, unwanted calories. Avoid it if you have a milk allergy, or are pregnant or breastfeeding. Also, it may interact with some medications, such as levodopa and certain antibiotics, so speak to your doctor and pick a supplement that’s been third-party tested for quality and safety.
When’s the best time to use whey protein?
Your intake of protein from any source should be spaced throughout the day, as your body can only process about 20 to 40 g of protein at once. That said, it’s beneficial to take part of your daily dose of protein about 30 to 60 minutes after a workout to support muscle growth and recovery. Research also suggests that consuming whey protein before a meal may help regulate high blood sugar levels in people with type 2 diabetes.
Is whey protein used for weight loss?
Whey protein alone won’t make you lose weight. But it may help you reduce body weight and fat mass while maintaining muscle when used as part of a diet and exercise regimen.
Can whey protein make you gain weight?
Yes. If you’re underweight or want to gain muscle mass, whey supplements may help you meet your recommended daily protein intake, especially if you don’t have an appetite. If gaining weight isn’t your goal, though, it’s important to pay attention to the calorie content of whey protein products. Eating more calories than you burn will ultimately contribute to weight gain.
Additional reporting by Kathleen Ferraro.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
- Is Whey Protein Good for You? Cleveland Clinic. January 4, 2021.
- Cava E et al. Investigating the Health Implications of Whey Protein Consumption: A Narrative Review of Risks, Adverse Effects, and Associated Health Issues. Healthcare. January 18, 2024.
- Kamińska MS et al. The Impact of Whey Protein Supplementation on Sarcopenia Progression among the Elderly: A Systematic Review and Meta-Analysis. Nutrients. Apr 23, 2023.
- Sepandi M et al. Effect of Whey Protein Supplementation on Weight and Body Composition Indicators: A Meta-Analysis of Randomized Clinical Trials. Clinical Nutrition ESPEN. June 6, 2022.
- Rabie AS et al. Impact of Whey Protein Supplementation as Adjuvant Therapy on Malnourished Cancer Patients: Systemic Review and Meta-Analysis. Discover Food. October 24, 2024.
- Ang T et al. The Impact of a Single Dose of Whey Protein on Glucose Flux and Metabolite Profiles in Normoglycemic Males: Insights Into Glucagon and Insulin Biology. American Journal of Physiology-Endocrinology and Metabolism. November 17, 2023.
- Chiang S-W et al. Whey Protein Supplementation Improves Postprandial Glycemia in Persons With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrition Research. April 18, 2022.
- Vajdi M et al. The Effects of Whey Protein on Blood Pressure: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials. Nutrition, Metabolism, and Cardiovascular Diseases. May 25, 2023.
- Prokopidis K et al. The effects of whey protein supplementation on indices of cardiometabolic health: A systematic review and meta-analysis of randomized controlled trials. Clinical Nutrition. January 1, 2025.
- Samimi S et al. The Topical Formulation of Whey Protein for the Prevention of Pressure Ulcers in Critically Ill Patients: A Novel Intervention in a Randomized-Controlled Clinical Trial. Advanced Biomedical Research. June 30, 2023.
- Giglio BM et al. Effects of Whey Protein Supplementation on Adiposity, Body Weight, and Glycemic Parameters: A Synthesis of Evidence. Nutrition, Metabolism & Cardiovascular Diseases. February 2023.
- Get the Facts: Added Sugars. Centers for Disease Control and Prevention. January 5, 2024.
- DiNicolantonio JJ et al. Added Sugars Drive Insulin Resistance, Hyperinsulinemia, Hypertension, Type 2 Diabetes and Coronary Heart Disease. Missouri Medicine. December 2022.
- Yang M et al. Protein Powder Supplementation in Early Pregnancy and the Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study. Food & Function. April 24, 2023.
- Whey Protein: Interactions. Mosaic Life Care.
- Dietary Supplements: What You Need to Know. National Institutes of Health. January 4, 2023.
- Innocente-Alves et al. Whey as a Biotechnological Resource: Current Trends and Future Directions. ACS Food Science & Technology. July 31, 2025.
- Milk, whole, 3.25% milkfat, with added vitamin D. U.S. Department of Agriculture. December 16, 2019.
- Patel S. Emerging trends in nutraceutical applications of whey protein and its derivatives. Journal of Food Science and Technology. Jun 9, 2015.
- Yogurt, Greek, plain, whole milk. U.S. Department of Agriculture. April 28, 2022.
- Asaduzzaman M et al. Heat-Induced Interaction of Milk Proteins: Impact on Yoghurt Structure. International Journal of Food Science. September 22, 2021.
- Cheese, ricotta, whole milk. U.S. Department of Agriculture. December 16, 2019.
- Florio M et al. Evaluation of Chemical and Nutritional Characteristics of Ricotta Cheese from Two Different Breeds: The Endangered Italian Teramana Goat and the Cosmopolitan Saneen Goat. Foods. April 18, 2024.
- Rodriguez-Lopez P et al. Analysis and Screening of Commercialized Protein Supplements for Sports Practice. Foods. November 3, 2022.
- Tunick MH et al. Physical and Chemical Changes in Whey Protein Concentrate Stored at Elevated Temperature and Humidity. Journal of Dairy Science. March 2016.
- Dietary Guidelines for Americans. U.S. Department of Agriculture. December 2020.
- Assessing Protein Needs for Performance. Mayo Clinic Health System. July 17, 2023.
- Chapman I et al. Rational Use of Protein Supplements in the Elderly—Relevance of Gastrointestinal Mechanisms. Nutrients. April 8, 2021.
- Moon J et al. Clinical Evidence and Mechanisms of High-Protein Diet-Induced Weight Loss. Journal of Obesity & Metabolic Syndrome. September 30, 2020.
Meet Our Experts
Roxana Ehsani, MS, RD, CSSD, LDN
Medical Reviewer
Roxana Ehsani, MS, RD, CSSD, LDN, is a Washington, DC–based registered dietitian-nutritionist, board-certified specialist in sports dietetics, and media spokesperson, consultant, and content creator for food and nutrition brands.
Ehsani has appeared as a food and nutrition expert for television stations across the nation and in national publications, including Runner's World, Women's Health, and Glamour, and is a contributing writer for EatingWell. She has a strong background in sports nutrition and has worked with professional, Olympic, collegiate, and high school teams and individual athletes.
Kristeen Cherney, PhD
Author
Kristeen Cherney, PhD, is a freelance writer, essayist, author, and poet with more than 15 years of health writing experience for digital platforms such as Healthline, The Mighty, and LiveStrong. She’s covered nutrition, women’s and children’s wellness issues, as well as specialized topics ranging from diabetes and thyroid disease to anxiety, depression, asthma, allergies, and skin conditions.
With a doctorate in English (rhetoric and composition), Dr. Cherney focuses her academic scholarship on the intersection between disability and literacy. She also holds a Master of Arts in English and a Bachelor of Arts in communication.
Cherney has contributed to the books The Wiley Handbook on Violence in Education: Forms, Factors, and Preventions, Composing in Four Acts: Readings for Writers, and Georgia State University's Guide to First-Year Writing, as well as to scholarly journals like Praxis, the Journal of Teaching Writing, and the Journal of Dracula Studies.
Cherney enjoys running, meditating, hiking, and paddleboarding.
With a doctorate in English (rhetoric and composition), Dr. Cherney focuses her academic scholarship on the intersection between disability and literacy. She also holds a Master of Arts in English and a Bachelor of Arts in communication.
Cherney has contributed to the books The Wiley Handbook on Violence in Education: Forms, Factors, and Preventions, Composing in Four Acts: Readings for Writers, and Georgia State University's Guide to First-Year Writing, as well as to scholarly journals like Praxis, the Journal of Teaching Writing, and the Journal of Dracula Studies.
Cherney enjoys running, meditating, hiking, and paddleboarding.