Protein powder is one of the top nutrition supplements on the market.

Some people use it to support muscle growth, and others use it because they want to consume more protein than they’re getting from food alone. Protein powder can be part of a balanced diet.

However, you may wonder if consuming a lot of protein powder can be harmful. The short answer is no, but it may have minor side effects.

This article discusses whether consuming too much protein powder is dangerous, reviews the research on its side effects, and examines some misconceptions about protein powder.

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Protein powders are concentrated forms of protein from animal or plant sources. You can buy them at many health food stores and online, and there’s a wide range of brands, types, and flavors to choose from.

Animal-based protein powders are usually made of two milk proteins called whey and casein, with whey being more popular. While less common, protein powders containing beef or chicken protein are also available.

Whey protein powder is isolated from whey, a liquid byproduct of cheese making that manufacturers spray-dry into a powder (1, 2).

Plant protein powders can be made from various plant-based proteins, such as brown rice, pea, soy, and hemp. Typically, plant-based protein powders contain a blend of plant proteins (3).

Both types of protein powder will generally provide 20–30 grams of protein per scoop, so they are a great way to get additional protein in your diet. They also commonly contain added vitamins, flavors, and sweeteners.

People often use protein powder after workouts to support muscle growth. Your muscles need enough protein to rebuild muscle tissue after a strength training workout (4, 5, 6, 7).

You might use it if you have difficulty meeting your daily protein needs through food alone — for example, if you aren’t eating large amounts of food or you’re following a vegan diet (8, 9, 10).

That said, if you’re getting enough protein through food, it’s unlikely that you’ll see much benefit from taking protein powder.

The DRI (Dietary Reference Intake) for protein is 0.36 grams of protein per pound (0.8 grams per kg) of your body weight per day.

However, if you’re aiming to build muscle, this can go up to 0.6–0.9 grams per pound (1.4–2.0 grams per kg) per day. A good general rule is to try to get 20–40 grams of protein per meal (4, 5, 11, 12).

Summary

Protein powder is a concentrated form of protein from plant or animal sources. Available types include whey, casein, pea, soy, and rice.

Simply put, protein powder is not bad for you.

It’s a convenient source of protein that helps many people meet their daily protein needs.

Of course, if you have allergies to a certain type of protein or other ingredients in a protein powder, then it will cause you to have an allergic reaction. In that case, you should avoid that type of protein powder.

The ingredients in protein powders vary significantly among brands and products.

While the Food and Drug Administration regulates dietary supplements such as protein powder, manufacturers are responsible for evaluating the safety, effectiveness, and labeling of their products (13, 14).

This means that the labels on protein powders and other dietary supplements could provide misleading ingredient or product information. In fact, one study found that numerous protein powders actually contained lower-cost proteins such as chicken, rice, and soy (15).

Though this is rare, protein powders may sometimes contain harmful ingredients or substances that have been banned in sports. Fortunately, many reputable protein powder brands use third-party testing to demonstrate their products’ safety and transparency (16).

Try to select a protein powder from a reputable company with third-party testing. And make an effort to eat a balanced diet that includes plenty of protein-rich whole foods, such as lean meats, poultry, eggs, beans, lentils, tofu, nuts, and seeds.

Summary

Protein powder is not bad for you. Some protein powders may contain unwanted or harmful ingredients, but this is rare. Be sure to buy powders that have been through third-party testing — they will say this on the label.

You might be worried about taking too much protein powder because you’ve heard that it affects your liver, kidneys, or bones. But research has shown that these claims are false.

Here’s a look at these misconceptions in detail.

Kidney and liver function

One major concern some people raise about taking protein powder is that it affects the kidneys and liver.

Experts once thought that too much protein could damage the kidneys and liver in healthy people, but many recent studies have disproven this (17, 18, 19, 20).

In one study, 48 men and women consumed a high protein diet from both food and whey-beef protein powder during an 8-week heavy resistance training program. Those who took the protein powder didn’t have any difference in kidney function (21).

However, those with kidney disease or decreased kidney function have more difficulty excreting protein waste products in their urine and will need to monitor their protein intake.

Decreased kidney function is defined as an estimated glomerular filtration rate (eGFR) of less than 90 (22, 23).

Therefore, unless you have chronic kidney disease or decreased kidney function, consuming protein powder and other high protein foods is likely safe.

Bone health

People once thought a high protein diet was harmful for bone health. This myth was rooted in the idea that protein’s high acid content “stripped” bones of their calcium, leading to high calcium levels in the urine and weaker bones (24).

However, current research suggests that a high protein diet may actually boost bone health.

Researchers believe it does this by promoting calcium absorption, supporting the growth of skeletal muscle mass, and preserving bone mass during weight loss (24, 25, 26, 27).

In an 18-month high quality study, 280 older men and women consumed 45 grams of whey protein or a placebo each day. Results showed no differences in bone composition between the groups (28).

Interestingly, the whey protein group preserved significantly more muscle mass, suggesting that protein may help reduce age-related muscle loss. This may benefit bone health by allowing aging people to stay active longer (28).

Summary

To date, there is no evidence that consuming protein powder or high protein foods is harmful to bone, liver, or kidney health. If you have kidney issues, speak with a doctor before taking protein powder to make sure it’s safe for you.

Protein powders are generally recognized as safe, although you may experience digestive side effects if you consume large amounts of protein powder.

If you’re lactose intolerant or otherwise sensitive to lactose, dairy-based protein powder may lead to stomach upset, bloating, and gas. Instead, opt for a plant-based protein powder or try whey protein isolate, which is much lower in lactose than other dairy protein powders (29).

If you want to use plant-based protein powder, read the ingredient label carefully to identify any potential food allergens or sensitivities. For example, soy and gluten are common allergens found in plant-based protein powders (30).

Furthermore, those who have irritable bowel syndrome or are sensitive to FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols) may experience bloating and cramping from pea protein powder or powders with added sugar alcohols (31).

Companies may add sugar alcohols as low calorie sweeteners.

Trial and error will help you determine the best protein powder for you.

Summary

The main side effects of consuming a lot of protein powder are digestive issues such as bloating, gas, and cramping. If you have any food sensitivities, be sure to read the label first.

Most people’s bodies can process excess protein from food and supplements and can safely tolerate 1.14–1.5 grams per pound (2.5–3.3 grams per kg) of protein per day (4, 32).

However, more research is needed to investigate an upper limit for protein powder consumption.

Until then, if you want to use protein powder, stick to 1–2 servings per day and get the rest of your protein through food.

Summary

There’s no known safety limit for protein powder. Most research shows healthy people can tolerate up to 1.5 grams of protein per pound (3.3 grams per kg) of body weight per day from both food and protein supplements with no side effects.

Protein is important for growth and development during childhood and adolescence. Most experts agree that children and teens should get their protein from food sources such as (33, 34, 35):

  • meat
  • poultry
  • dairy
  • beans
  • lentils
  • eggs
  • tofu

In some cases, a healthcare professional might recommend that a child take a protein supplement, such as PediaSure, if the child is malnourished, is a picky eater, or has strict dietary restrictions.

While there is no data to suggest that protein powder is harmful to children and teens, relying on protein powder and supplements may displace nutritious, whole foods in the diet. Therefore, protein-rich whole foods should come first (36).

If you’re concerned that your child or teen isn’t getting enough protein, speak with a registered dietitian, a qualified nutritionist, or your child’s doctor.

Summary

Children and teens should aim to get their protein from food first to ensure they’re getting enough calories and nutrients. A healthcare professional may recommend a protein supplement for picky eaters or those with malnutrition.

Protein powder can be a great addition to a balanced diet. However, here are a few important considerations.

Purchasing a safe protein powder

It might feel overwhelming to choose a protein powder from the many available options online or at the health food store. Here are a few things you can do to make it easier:

  • Look for third-party testing. Check product labels for certifications from reputable third-party organizations such as NSF International’s Certified for Sport, USP, Informed Choice, ConsumerLab, and the Banned Substances Control Group.
  • Read the label. If you’re looking to avoid a certain ingredient, be sure to read the label carefully. In addition to the ingredients list, a label may give information about a product, such as whether it’s vegan or gluten-free.
  • Look at the serving size. The best protein powders will contain 20–30 grams of protein per scoop.

Use it as a supplement, not a replacement

Though protein powder can be a great addition to your diet, you don’t need to consume it to be healthy.

Whole, protein-rich foods contain vitamins and minerals that are important for health. What’s more, they take longer to digest than protein powder, so they may make you feel full longer.

On the other hand, protein powder is considered “predigested” and will leave your stomach more quickly after you consume it than whole foods do (37).

Instead, use protein powder to supplement your balanced diet at times when you may not be able to meet your protein needs.

Summary

When shopping for a protein powder, look at the label to ensure the product has been third-party tested and doesn’t contain any unwanted ingredients. Ideally, use protein powder in addition to a nutritious diet, not as a replacement for one.

If you’ve ever wondered whether protein powder is safe to use, you can rest assured that it is.

Due to protein powder’s popularity, many research studies have investigated its safety and effectiveness. They’ve found that it’s safe and does not pose a risk to bone, liver, or kidney health, even if you take it in large amounts.

Still, it’s best to get most of your protein from whole, minimally processed foods and use protein powder only to address any unmet protein needs.

The best protein powders will be third-party tested, contain 20–30 grams of protein per scoop, and contain ingredients you can personally tolerate.