Let’s be honest–it can be hard to beat a good protein shake, especially if you’re looking to get more protein into your diet, supplement extra gains in the gym or drop a few pounds. This convenient source of nutrition has long been praised by athletes and recreational gym-goers alike for its convenient role in building lean muscle mass, improving strength, and promoting tissue repair. 

But with so many protein powder options available on the market these days, how do you know which one is best for you and your needs? Here's what science has to say about the differences between whey protein and vegan protein powder.

What is whey protein?

Whey protein is one of the primary proteins found in dairy foods, and is considered a complete protein, as it contains all of the essential 9 amino acids. Furthermore, it is highly digestible, rapidly absorbed, offers around 25 g of protein/serving and is rich in leucine (which helps kick start muscle repair and growth) [

1

]. For all of these reasons, whey is usually a top choice among gym-goers and athletes.

Another protein found in dairy products is casein protein, which provides your body with a slow, steady release of amino acids. This makes it ideal for fasting situations (such as while you sleep), weight loss (as it promotes satiety), and muscle growth. Casein differs from whey protein in the fact that whey is more rapidly absorbed, hence may be more useful after a workout. 

Some additional benefits of whey protein include:

• Lower blood pressure. Studies have found that whey protein may help lower blood pressure in pre-hypertensive adults [

  2

  ]. 

• More stable blood sugar. Whey protein can moderate blood sugar levels when taken before a high-carbohydrate meal and may therefore be beneficial for those with type 2 diabetes [

  3

  ]. 

• Lower cholesterol levels. Whey protein may be supportive of heart health, especially among those who are overweight or obese, as research has found that high doses of whey protein can help reduce cholesterol levels and improve lipids over time [

  4

  ,

  21

  ,

  22

  ]. 

Does whey protein cause acne?

Despite some cases reporting that whey protein causes acne, there isn’t enough compelling evidence to suggest a correlation between the two. Much of the research done is on very small samples of the population [

5

,

6

]. 

While whey protein may not directly cause acne, there might be other reasons as to why your skin is breaking out. Some common contributing factors to consider may include oily skin, humid environments, hormonal disruptions, poor sleep, obesity, and high fat and high sugar diets [

7

]. 

Whey isolate protein powder

The difference between whey protein and whey isolate protein powder is that the latter undergoes more processing, which results in a higher protein content with less carbs, lactose and fat, which have been filtered out [

8

]. As such, whey isolate may be a better option for those who are lactose intolerant or have sensitive digestive systems. 

How much whey protein per day?

According to the Recommended Dietary Allowance (RDA) for protein needs, you need at least 0.8 g of protein/kg of body weight/day to meet the body’s most fundamental nutritional needs (like repairing tissue, coordinating bodily functions, maintaining pH levels, and allowing metabolic reactions) [

9

]. However, physical activity can increase these needs to 1.2–2.0 g of protein/kg of body weight/day to further support muscle repair, remodeling, metabolic adaptation and protein turnover [

10

]. 

These numbers may vary depending on your activity level, age, and other needs, so talk with a dietitian or your healthcare provider to see what is right for you.

While you can obtain protein through dietary sources (like eggs, dairy, lean meat, poultry, fish, beans, lentils, soybeans, or tofu), whey protein powders may also be convenient and beneficial for meeting your nutritional needs. 

However, excessive consumption of whey protein may cause digestive problems (such as nausea, bloating, cramping, flatulence, and diarrhea), so be cautious of how much you consume.

When to take whey protein

When you should take whey protein depends on your health and performance goals. 

• Muscle repair and recovery. It’s recommended to drink protein shakes within two hours of exercise. According to the International Society of Sports Nutrition, consuming 20-40 g of high-quality protein with leucine (like quick-digesting whey protein) shortly after exercise stimulates robust increases in muscle protein synthesis that can benefit both performance and recovery [

  11

  ].

• Weight loss. Research suggests consuming 25-30 g of quality protein at breakfast, lunch, and dinner may benefit weight loss by improving energy metabolism, protein synthesis, and appetite control [

  12

  ]. If you’re trying to lose weight and are not getting at least 25-30 g of protein at breakfast, drinking a whey protein shake in the morning may help your weight loss efforts.

Does whey protein expire?

When stored in a dry, cool spot, whey protein powder has a shelf life of 9-18 months [

13

,

14

]. However, if you notice a rancid smell, bitter taste, changes in color, or clumping, it’s best to throw the product away and purchase a fresh one.

Vegan protein powder 

If you’re a vegetarian, vegan, or have a dairy allergy, you may want to consider some different options for protein supplementation. Here are some of the most common types of plant based protein powders.

Soy protein powder

Soy is a complete protein and aids in muscle building. It contains leucine (a branched-chain amino acid, or BCAA) to enhance muscle protein synthesis; however, studies have found that both whey and casein may be superior in this respect [

15

]. 

Soy protein comes from the protein found in soybeans [

23

]. Soy protein isolate powder is made from defatted soybean flakes that have been rinsed in alcohol or water to remove the sugars and fiber [

24

]. They're then dehydrated and powdered to create soy protein powder. 

With 23 g of protein/serving, soy can serve as a good source of protein for those who have a dairy allergy or follow a vegetarian or vegan diet.

Interestingly, emerging evidence suggests that combining dairy and soy protein may result in greater muscle protein synthesis than if you were to consume each one separately, though we’ll need further research in humans to have more conclusive evidence [

16

]. 

Hemp protein powder

Just like whey and soy, hemp protein is also considered a complete protein, as it has all 9 essential amino acids. Additionally, it’s easy to digest, and has 15 g of protein and 8 g of fiber/serving, making this a good option for those with dairy allergies or who follow a plant-based diet [

17

]. 

Hemp protein powder is made by grinding pressed hemp seeds into a fine powder. The seeds are taken from the whole hemp seed meal that has had the oil removed [

25

].

Pea protein powder

Coming in at 15 g of protein/serving, pea protein is another good vegan protein powder option. 

Not only is it rich in BCAAs, but it also contains arginine and leucine to promote healthy blood flow, muscle growth, and protein synthesis [

18

]. 

Pea protein powder is made by isolating the protein from ground yellow peas [

26

].

One study showed that active men who took pea protein powder experienced a greater increase in bicep muscle thickness than those who had whey protein [

19

]. Moreover, research has found that pea protein might assist with weight loss by increasing satiety [

20

]. 

Which option is best?

Whey protein and vegan protein powders are all good options when it comes to supplementation. Research supports both for performance improvements and meeting your daily protein needs. You may want to consider the other ingredients in the powder as well, especially if you have allergies or intolerances. Ultimately, the best choice for you is one that is accessible, fits your eating style and makes you feel your best. 

Some protein powders also contain additional vitamins and minerals, such as iron, B Vitamins and more. Check with your healthcare provider or dietitian to see if these are recommended for you and your health goals.  

Precautions

Despite the benefits, there are potential risks associated with protein powder. It’s considered to be a supplement (which means that it’s not regulated by the FDA), and some may contain possible contaminants like arsenic, cadmium, mercury, and lead [

27

,

28

]. Others might also be higher in sodium, which may be contraindicated for some people. Moreover, some people might also experience possible digestive upset from consuming excess amounts of protein. 

Furthermore, some protein powders may contain added sugars (which might increase the risk of chronic disease) and artificial sweeteners (like aspartame, acesulfame-K, and sucralose) that have been correlated with an increased risk of cancer [

29

,

30

]. 

FAQs on protein powder

Hungry for more? Check out these nutrition FAQs on protein powder.

• Are there any dangerous ingredients in protein powder?

   

• Is it okay to drink protein shakes everyday?

• Should you drink a

  protein shake before or after workout

  ?

• When to drink protein shakes for weight loss?

Summary

Protein powder has long been praised by athletes and recreational gym-goers alike for its role in building lean muscle mass, improving strength, and promoting tissue repair. But with so many protein powder options on the market, it can be hard to sort through the noise to decide which one works best for you and your needs. 

Whey protein (dairy-based) and vegan protein (like soy, hemp, and pea) are the two main categories when it comes to protein powders. While they are all good protein supplement options, the best choice for you is the one that fits your eating style and makes you feel your best. 

Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.