Your Complete Guide to Whey Protein

woman mixing protein shakel

You’re likely aware of whey protein powder as a supplement. Maybe you’ve tried it or even consume it regularly. It’s commonly used as a method to increase muscle mass and comes in a variety of forms. As with numerous health and wellness supplements on the market, understanding the ins and outs of whey can be overwhelming.

Whether you take it as a post-workout recovery drink or are wondering if it could help you gain muscle, this guide to whey protein will answer all of your questions. Let’s get started!

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What Is Whey Protein?

This wouldn’t be a guide to whey protein if we didn’t start with the basics. Whey protein is one of the two main proteins found in cow’s milk. In the nursery rhyme where Little Miss Muffet is eating her curds and whey, the whey is the liquid that has separated from the cheese curds. It is a byproduct of the cheesemaking process. Liquid whey becomes a concentrated whey protein when dried. Not only is it manufactured as a protein supplement, but it is also used as a food additive.

Whey protein contains all nine essential amino acids (this includes branched-chain amino acids) and is therefore considered a complete protein. It is quickly absorbed and has been found to enhance the benefits of physical activity alone.(1) Whey protein has been associated with weight loss, muscle growth, improved strength, and muscle recovery.(2)

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Benefits of Whey Protein

Whey protein used as a supplement provides a wide variety of potential benefits:

  1. Helps meet protein needs. The International Society of Sports Nutrition (ISSN) recommends using protein supplements to meet your specific protein needs throughout the day.(3) Because active individuals likely require a higher protein intake throughout the day, it can be difficult to meet these requirements through whole foods alone. Taking a protein supplement, like whey protein, ensures enough high-quality protein is being provided to meet the body’s protein needs.
  2. Supports muscle growth. Whey protein has been shown to improve lean body (muscle) mass in people participating in resistance training.(4) It acts to help build muscle and improve the repair process. In other words, whey protein can increase muscle mass without having an effect on fat mass.(5) Any weight put on during this time is muscle only, and no additional fat is gained.
  3. Provides a concentrated source of protein. Most whey protein supplements provide anywhere from 20 to 30 grams of protein per serving. Because you can get such a boost of protein from one or two scoops of powder, consuming whey protein can be a very convenient way to ensure that you are meeting your protein needs.
  4. May help lower blood pressure. Research indicates that consumption of whey protein can actually decrease blood pressure over time. One study in particular found that those taking whey protein lost a significant amount of weight compared to those not taking whey protein.(6) This weight loss could also contribute to a reduction in blood pressure. Sounds like two for the price of one.
  5. May help skin and wound healing. An adequate supply of protein is crucial to wound healing. Considered one of the highest quality proteins available, whey protein contains all essential amino acids and supplies nutrients essential for cell growth, thus promoting wound healing.(7)
  6. May help blood sugar control. A large meta-analysis that included 22 studies(8) suggests that whey protein produces a significant reduction in glucose response and A1c measurements. When taken around mealtimes, whey protein can reduce blood glucose levels after eating.(9) This effect may be related to protein’s ability to slow digestion and ultimately slow carbohydrate absorption.
  7. Hunger reduction. Whey protein can reduce the feeling of hunger between meals. Studies show that it can suppress the appetite depending on the time of consumption.(10) For example, when paired with a balanced meal, consuming a whey protein supplement has been shown to increase feelings of satisfaction and fullness after a meal.(11)
  8. May help aid in weight loss. After learning about the numerous benefits of whey protein, it should come as little surprise that it also helps support weight loss and weight maintenance. This is likely due to many of the reasons mentioned above, such as its hunger-reducing and blood-sugar controlling effects. Research suggests that whey protein can be an effective tool in weight loss.(12)

Effects of Whey Protein on Muscle Building

From a scientific perspective, we are always interested in the effect protein has on muscle protein synthesis, which is really just a fancy way of saying muscle growth. It has been mentioned throughout the literature that whey protein is a high-quality protein which is easily absorbed by the body.(13) This is especially true when compared to other plant-based proteins, like soy or wheat proteins. When protein is easily absorbed by the body, more of it can be utilized by the muscles. In fact, the protein consumed can actually stimulate muscle protein synthesis and jumpstart muscle repair and growth.

Additionally, when focusing on muscle growth, we have to consider muscle breakdown. Muscle breakdown occurs after exercise or when we’re not taking in enough calories. It’s common for people trying to lose weight to lose fat and muscle because they aren’t meeting their caloric needs or supporting muscle mass by eating enough protein. Ensuring adequate protein supplementation with a high-quality protein, like whey, will help preserve muscle during weight loss.

So to summarize, it’s important to start with a high-quality, easily absorbed protein, like whey, in order to maximize potential muscle growth.

How to Take Whey Protein

Whey protein most commonly comes in powder form. This form can be added into drinks and baked goods. It is recommended to take protein supplements as a means of meeting daily protein needs.

To determine your protein requirements, the ISSN recommends consuming 1.4 to 2.0 grams of protein per kilogram (kg) per day. This is higher than the Recommended Daily Allowance (RDA) of 0.8 grams of protein per kilogram because it takes into account activity and muscle growth.

We can work this out with an example of a 175-pound person. First, we need to convert pounds (lb) to kilograms (kg) by taking the weight in pounds and dividing it by 2.2.

  • 175 lb / 2.2 = 80 kg

Now we can multiply the weight in kilograms by the protein recommendation of 1.4–2.0 grams.

  • 80 kg weight x 1.4 g protein = 112 g protein per day

We now know that 112 grams of protein per day is the low end of the range for this individual’s protein requirements. Now let’s calculate the high end of their recommended protein range.

  • 80 kg weight x 2.0 g protein = 160 g protein per day

Based on protein recommendations provided by the ISSN, this individual’s protein needs are between 112 grams and 160 grams of protein per day.

It’s important to note that bodybuilders and certain athletes may require even more protein throughout the day. A high-protein diet, however, is not suitable for some medical conditions. Be sure to get clearance from your doctor before you decide to significantly increase your protein intake.

Incorporating Whey Protein Into the Diet

As mentioned, whey protein often comes in powder form that can be mixed into drinks and baked goods. It’s also readily available in protein bars, packaged goods, and premixed shakes. Here are some ways to incorporate whey protein into your diet:

  • Start your day off with a protein punch by adding a scoop of whey to your morning coffee. This works especially well with an unflavored whey supplement.
  • Not a coffee drinker? Add a serving of whey to overnight oats or a yogurt parfait. This is when it can be fun to mix up the flavors.
  • Bump up the protein in your pancakes by replacing some of the flour with protein powder.
  • You can enjoy your whey protein in a shake before or after exercising as a pre-workout or recovery drink or as a snack any time of the day.
  • Have a minimally processed protein bar a couple of hours after lunch to avoid that mid-afternoon slump.
  • Mix unflavored whey protein into your mashed sweet potatoes, white potatoes, or cauliflower during lunch or dinner.

Types of Protein

Whey protein is often sold in three main forms: whey protein concentrate, whey protein isolate, and hydrolyzed whey protein. Let’s get into the differences and similarities between each.

Whey Protein Concentrate

During the cheesemaking process, milk is curdled and separated from the remaining liquid. This liquid is called whey, and it is high in protein. The liquid is later dried and made into a concentrated form. This is the most basic form of whey protein.

This concentrated form is used in many applications in the food manufacturing process. It’s also sold in powdered form as a nutrition supplement or mixed into protein bars, sports beverages, and other baked goods. Whey protein concentrate is a rich source of protein containing all nine essential amino acids, including branch-chain amino acids, as well as glutamine. It’s also the least expensive form of whey protein sold on the market.

Whey Protein Isolate

Whey protein isolate is, as it sounds, whey protein that has been isolated from other ingredients. For example, it’s natural for whey protein to contain small amounts of lactose. Lactose is a sugar that many people can’t digest, causing gas, bloating, and diarrhea. Whey protein isolate is devoid of lactose because it has undergone a microfiltration process to remove any lactose.

This filtration process also removes additional fat, cholesterol, and carbohydrates, resulting in a lower-calorie product that typically has a slightly higher protein content than that of whey protein concentrate. The major benefit of whey protein isolate is that it is more easily digested. It can be a great option for those who feel stomach upset or bloating after consuming a traditional whey protein supplement.

Hydrolyzed Whey Protein

Hydrolyzed whey protein is whey protein isolate that has been even further processed. The term hydrolysis means that water plays a role in the biochemical breakdown of bonds. Heat, enzymes, or acids are often used in this breakdown process. In terms of hydrolyzed whey protein, bonds between the amino acids have been broken down.

In essence, the whey protein has been pre-digested because the hydrolysis has done some of the initial digestion work. This is a selling point for manufacturers which claim that the absorption rate of the protein will be much faster due to the pre-digestion. However, whey protein is generally absorbed by the body very quickly, so a slight increase in speed may not offer much additional benefit. At this time, there is no evidence that hydrolyzed whey protein has an increased beneficial effect on muscle growth.(14)

FAQs About Whey Protein

How should I take whey protein for best results?

For best results, whey protein should be taken to meet your unique protein needs. First determine how much protein you need in a day, then figure out how much protein you usually consume. The difference between the two will tell you how much additional protein you need if any. You can meet your remaining protein needs with a whey protein supplement taken anytime during the day.

Which whey protein is best for beginners?

Look for a whey protein that comes in a wide range of flavors. Getting used to the taste of protein supplements can take time for some. By trying different flavor options, you’ll eventually find one that you enjoy and can easily incorporate into your routine.

Is whey protein better with milk or water?

This depends on the type of whey protein and flavor chosen. Let your taste buds decide. Just remember that with the addition of milk, you will be taking in added calories, protein, and, potentially, fat from the milk itself.

Can I drink whey protein every day?

Sure. If you are in good health and have been cleared by a physician to consume a protein supplement, whey protein is safe to have daily.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.


  1. Ha E, Zemel MB. Functional properties of whey, whey components, and essential amino acids: mechanisms underlying health benefits for active people (review). J Nutr Biochem. 2003 May;14(5):251-8. doi: 10.1016/s0955-2863(03)00030-5. PMID: 12832028.
  2. Hulmi JJ, Lockwood CM, Stout JR. Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein. Nutr Metab (Lond). 2010 Jun 17;7:51. doi: 10.1186/1743-7075-7-51. PMID: 20565767; PMCID: PMC2901380.
  3. Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M, Ziegenfuss TN, Ferrando AA, Arent SM, Smith-Ryan AE, Stout JR, Arciero PJ, Ormsbee MJ, Taylor LW, Wilborn CD, Kalman DS, Kreider RB, Willoughby DS, Hoffman JR, Krzykowski JL, Antonio J. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017 Jun 20;14:20. doi: 10.1186/s12970-017-0177-8. PMID: 28642676; PMCID: PMC5477153.
  4. West DWD, Abou Sawan S, Mazzulla M, Williamson E, Moore DR. Whey protein supplementation enhances whole body protein metabolism and performance recovery after resistance exercise: a double-blind crossover study. Nutrients. 2017 Jul 11;9(7):735. doi: 10.3390/nu9070735. PMID: 28696380; PMCID: PMC5537849.
  5. Duarte NM, Cruz AL, Silva DC, Cruz GM. Intake of whey isolate supplement and muscle mass gains in young healthy adults when combined with resistance training: a blinded randomized clinical trial (pilot study). J Sports Med Phys Fitness. 2020 Jan;60(1):75-84. doi: 10.23736/S0022-4707.19.09741-X. Epub 2019 Sep 23. PMID: 31565912.
  6. Yang J, Wang HP, Tong X, Li ZN, Xu JY, Zhou L, Zhou BY, Qin LQ. Effect of whey protein on blood pressure in pre- and mildly hypertensive adults: a randomized controlled study. Food Sci Nutr. 2019 Apr 21;7(5):1857-1864. doi: 10.1002/fsn3.1040. PMID: 31139400; PMCID: PMC6526665.
  7. Garraud O, Hozzein WN, Badr G. Wound healing: time to look for intelligent, 'natural' immunological approaches? BMC Immunol. 2017 Jun 21;18(Suppl 1):23. doi: 10.1186/s12865-017-0207-y. PMID: 28681702; PMCID: PMC5499069.
  8. Amirani E, Milajerdi A, Reiner Ž, Mirzaei H, Mansournia MA, Asemi Z. Effects of whey protein on glycemic control and serum lipoproteins in patients with metabolic syndrome and related conditions: a systematic review and meta-analysis of randomized controlled clinical trials. Lipids Health Dis. 2020 Sep 21;19(1):209. doi: 10.1186/s12944-020-01384-7. PMID: 32958070; PMCID: PMC7504833.
  9. Stevenson EJ, Allerton DM. The role of whey protein in postprandial glycaemic control. Proc Nutr Soc. 2018 Feb;77(1):42-51. doi: 10.1017/S0029665117002002. Epub 2017 Sep 25. PMID: 28942740.
  10. Rigamonti AE, Leoncini R, Casnici C, Marelli O, Col A, Tamini S, Lucchetti E, Cicolini S, Abbruzzese L, Cella SG, Sartorio A. Whey proteins reduce appetite, stimulate anorexigenic gastrointestinal peptides and improve glucometabolic homeostasis in young obese women. Nutrients. 2019 Jan 23;11(2):247. doi: 10.3390/nu11020247. PMID: 30678029; PMCID: PMC6412413.
  11. King DG, Walker M, Campbell MD, Breen L, Stevenson EJ, West DJ. A small dose of whey protein co-ingested with mixed-macronutrient breakfast and lunch meals improves postprandial glycemia and suppresses appetite in men with type 2 diabetes: a randomized controlled trial. Am J Clin Nutr. 2018 Apr 1;107(4):550-557. doi: 10.1093/ajcn/nqy019. PMID: 29635505.
  12. Batsis JA, Petersen CL, Cook SB, Al-Nimr RI, Driesse T, Pidgeon D, Fielding R. Impact of whey protein supplementation in a weight-loss intervention in rural dwelling adults: A feasibility study. Clin Nutr ESPEN. 2021 Oct;45:426-432. doi: 10.1016/j.clnesp.2021.07.006. Epub 2021 Jul 24. PMID: 34620350; PMCID: PMC8502229.
  13. Stokes T, Hector AJ, Morton RW, McGlory C, Phillips SM. Recent perspectives regarding the role of dietary protein for the promotion of muscle hypertrophy with resistance exercise training. Nutrients. 2018 Feb 7;10(2):180. doi: 10.3390/nu10020180. PMID: 29414855; PMCID: PMC5852756.
  14. A Castro LH, S de Araújo FH, M Olimpio MY, B de B Primo R, T Pereira T, F Lopes LA, B S de M Trindade E, Fernandes R, A Oesterreich S. Comparative meta-analysis of the effect of concentrated, hydrolyzed, and isolated whey protein supplementation on body composition of physical activity practitioners. Nutrients. 2019 Sep 2;11(9):2047. doi: 10.3390/nu11092047. PMID: 31480653; PMCID: PMC6769754.