Are There Side Effects To Taking Protein Powder?

If you're thinking about trying protein powder to boost your health and fitness, you're in good company.

Once reserved for bodybuilders, athletes, and older people, protein powders have become pantry shelf staples for most health-conscious Americans.

People take protein powders for different reasons, but often it's to help with weight management, muscle building, curbing sugar cravings, or meeting specific protein targets.

But are there any protein powder side effects to consider before diving in?

The short answer is yes. Taking excess protein powder and/or protein powder from the wrong sources and brands can cause side effects. 

However, with an understanding of your nutritional needs and how to vet a high-quality and tested protein powder, you can enjoy all the benefits without the risks. 

What is Protein Powder?

Protein powders are dietary supplements comprising various forms of protein such as whey, soy, rice, pea, hemp, cranberry seed, casein, hydrolyzed beef, and others.

Protein powders, such as Biochem's Whey or Vegan proteins, can be purchased online or at your local grocery or natural foods store.

As mentioned previously, people take protein powders for various reasons including to support a healthy weight, help build muscle or prevent muscle loss, for exercise recovery, blood sugar balance, or to meet specific protein targets or requirements.

Protein powders can also be helpful for people who eat more restrictive diets, such as vegans or vegetarians, and older people.

As dietary supplements, protein powders must be manufactured under FDA Current Good Manufacturing Practices (cGMP) guidelines. 

However, not every supplement company goes above and beyond in its protein powder sourcing, formulations, and testing of raw materials and the end product.

This has caused some quality and contamination issues for many protein powder brands, and has led to some unfortunate side effects.

We'll discuss this more in subsequent sections, including how to choose a clean, safe, and tested protein powder.

What are the Benefits of Protein Powder?

Not everyone needs a protein supplement to be healthy.

If you're eating high-quality protein at most meals and snacks, you're likely getting enough protein and amino acids to meet your daily requirements.

However, supplemental protein has been shown to be beneficial for various aspects of health and fitness, including:

• Weight management
• Muscle building
• Exercise recovery
• Promoting a healthy inflammatory response and lowering oxidative stress
• Immune support (whey protein)
• Meeting daily protein requirements for people on restrictive diets
• A healthy pregnancy
• Blood sugar balance
• Preventing sarcopenia in older people

Many health and fitness practitioners also promote the perks of protein and protein powders to help promote metabolic health, curb sugar cravings, support balanced blood sugar, and promote a healthy appetite.

Protein shakes can also provide a quick source of high-quality protein and nutrients when you don't have time to stop for a healthy snack or a full meal.

The bottom line is that protein powder can provide various health benefits so long as it's from a high-quality source and taken responsibly as part of a healthy, balanced diet.

However, if protein powder is abused (like any food, drug, or supplement), it can cause mild to severe side effects, which we'll explore now.

Is Protein Powder Safe? Protein Powder Side Effects

Protein powder is generally very safe, even in higher doses for muscle building or athletic training.

However, some people experience side effects due to the type of protein powder, how it's used (or abused), and the brand or source.

Most side effects are mild and can be mitigated by dialing in the correct form and dosage of protein powder for you personally. Ask your healthcare provider if you need advice on dosage.

Others come from overuse or contaminants in protein powders, so proper dosage and choosing a clean brand are essential.

The following are five possible side effects of protein powders.

Protein Powders May Contain Harmful Contaminants

Several reports have exposed various contaminants of concern in protein powders, specifically plant and some whey varieties.

Some of the most concerning are: 

• Heavy metals like lead, cadmium, and arsenic, which are neurotoxic and potentially carcinogenic
• Pesticides, which can disrupt gut health, nervous system function, development, and some are possible or confirmed carcinogens
• BPA and BPS, plasticizer chemicals that are known endocrine disruptors and possible carcinogens

According to a recent study by The Clean Label Project, a whopping 47% of the protein powder brands tested exceed California's Prop 65 safety thresholds for toxic metals.

Not what you want in your designer protein shake!

So, where are these contaminants coming from?

• Pesticides come from raw materials that are not grown or raised (in the case of dairy cows) organically
• BPA and BPS likely come from product packaging. However, these pervasive chemicals also exist in water and our environment. They may also leach from manufacturing equipment
• Heavy metals, which were more of a problem in plant-based proteins and especially chocolate varieties, likely come from three sources:

1. The soil, which contains naturally occurring heavy metals and those from pollution
2. Pesticides used to grow the plants: Many pesticides are heavy-metal based
3. Manufacturing equipment

When consumed in large amounts, these contaminants can cause a wide range of side effects, including neurological damage, hormonal imbalance, weight gain, cancer, organ damage, cognitive decline, congenital abnormalities, and many other ailments.

That said, these contaminants are present in most foods we eat (even baby foods have a heavy metal problem), and not all protein powders tested posed a threat.

This is why it is essential to choose a clean, sustainably sourced brand that employs rigorous safety tests of raw materials and finished products!

Biochem is proud to have been listed as one of the cleanest and safest brands by Consumer Reports. 

We are also NSF cGMP-certified and certified gluten-free. We manufacture our products in certified organic facilities and employ raw material and end-product testing to ensure a safe and clean protein powder you can trust.

Related reading: Is Gluten-Free Protein Powder Healthier? Discover The Benefits Here

Certain Protein Powders May Cause Gastrointestinal Trouble For Some People

Not everyone responds favorably to all types of protein powder.

For example, people with lactose or casein intolerance or sensitivity likely will not digest whey protein very well.

Others have difficulty digesting certain plant protein types, like soy or pea.

If you have gluten intolerance or sensitivity, be sure only to use brands that are third-party certified gluten-free, like Biochem.

Consuming too much protein powder, especially without extra fiber, such as in smoothies, can also cause gastrointestinal trouble.

Here are a few tips to help reduce or prevent tummy trouble from protein powder:

• Avoid whey or casein-based protein if you're sensitive or allergic to dairy. Exception: Whey protein isolate is very low in lactose and is, therefore, typically suitable for lactose-tolerant people. Use your own discretion.
• If pea protein causes gas or bloating, try other varieties, like whey, or look for mixtures of pea with other plant proteins, like rice, hemp, or cranberry seed.
• Opt for whey protein isolate vs. whey protein concentrate, which may be better absorbed and is often easier to digest.
• Read labels carefully to rule out other gastrointestinal irritants. Fiber, fillers, soy, gluten, and sugar alcohols, like erythritol or xylitol, can cause gastrointestinal side effects.
• Avoid taking excessive amounts of protein powder, especially without adequate fiber and water.
• Consider and re-evaluate your overall protein intake, as too much protein from all sources can cause gastrointestinal issues.
• If all else fails, consider what else you're adding to your protein shakes, as it could be another ingredient or the combination that's the problem. Experiment and see what recipe works best.

Abusive Use of Whey Protein May Negatively Impact Liver and Kidney Health

These side effects are controversial due to conflicting research and opinions.

However, more research has shown that excessive or abusive intake of protein powders, specifically whey protein, may have adverse effects on the liver and kidneys.

The theory is that any type of protein increases body acidity in the form of uric acid, which must be broken down and excreted by the liver and kidneys.

Therefore, excess protein can cause weakening or damage, especially in people with pre-existing liver or kidney conditions.

There is also the issue of contaminants in certain protein powders, like heavy metals, which can also harm the liver and kidneys, and were not discussed in these studies.

Fortunately, there is no evidence that consuming moderate or recommended amounts of protein or protein powder (like one scoop a day) will cause harm.

However, if you have kidney or liver disease, talk with your healthcare practitioner before taking a protein powder supplement.

Related Reading: Benefits Of Whey Isolate Protein

Soy Protein Powder May Cause Hormonal Imbalance

Soy was once the darling of the natural health, fitness, plant-based, and supplement world.

Rich in protective isoflavones, calcium, and protein, it appeared to be nature's perfect source of plant-based protein.

However, most experts now recommend consuming soy in small quantities and in its whole, traditional, or least processed state, such as edamame, soymilk, or tofu.

This is NOT what you get in a soy protein isolate, the most common form used in soy protein powders.

Although a little soy protein isolate is unlikely to cause harm, soy is a rich source of phytoestrogens, a type of plant-based estrogen-mimicking compound. 

This is why moderate amounts of whole soy may be helpful for women during perimenopause or menopause.

However, since soy protein isolate is a concentrated form of soy, you could be getting too much of a potentially good thing.

So, if you don't want or need more estrogen in your body, or are dealing with any hormonal issues, supplementing with soy protein isolate may cause more hormonal harm than good.

Fortunately, other plant-based protein sources used in protein powders, such as hemp, cranberry seed, rice, and pea, will not upset estrogen balance.

Whey Protein May Lower Blood Pressure

Studies suggest dairy products, including whey protein, can help lower blood pressure.

If you have normal or high blood pressure, this could be a pleasant side effect! 

However, if you suffer from low blood pressure, talk to your doctor before taking whey protein supplements.

Plant proteins do not have this effect and may be a better option, but check with your doctor first.

How Much Protein Powder Should You Take?

The amount of protein powder you should take depends on your diet and your health or fitness goals.

The official Recommended Dietary Allowance (RDA) for protein is or 0.36 grams per pound of body weight.

So a 150-pound person would need to consume 54 grams daily.

However, some experts argue that's not enough and recommend aiming for 0.5-1 gram of protein per pound of body weight, especially if you're trying to build muscle, lose weight, support a healthy appetite, and/or improve endurance.

Most protein powders contain between 15-30 grams of protein, so one scoop is typically adequate for most people, although athletes or fitness buffs may choose to consume more.

Talk to your healthcare practitioner for individual recommendations.

How To Find Safe & Clean Protein Powders to Support Your Health

Protein powders can be a beneficial and nutrient-dense addition to a healthy diet, but, as you've just learned, quality really counts.

Ask the following questions when considering a protein powder supplement:

• Was the brand flagged as high in contaminants from recent studies, like Consumer Reports?
• Does the brand employ rigorous testing of raw materials and the finished product?
• Are the raw materials clean?
• For example, the cleanest whey protein comes from pasture-raised cows and plant proteins should be organic and/or sustainably sourced.
• Is the brand certified gluten-free?
• Is the product made in a third-party certified cGMP facility?
• For plant proteins, are they genetically verified vegan (some tests have revealed protein powders may contain animal products that are not disclosed on labels).
• Does the product contain any additives, preservatives, artificial colors or flavors?
• Is the product naturally sweetened or artificially sweetened?
• How many calories are in a scoop?
• Does the product contain soy or any other allergens?
• If you're vegetarian, look for a Vegetarian Certification on Whey Protein powders
• Do the plant proteins have a complete amino acid profile? This typically requires using more than one type of plant protein.

The good news is, there are a few brands out there that meet this criterion, including BioChem.

Shop our certified gluten-free Whey Protein Isolates (sugar-free or naturally sweetened, grass-fed, and ultra delicious) or Plant Proteins (sustainably-sourced, genetically-verified vegan, and certified vegetarian) to learn more.

References Mentioned in This Article

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• CLP Insights: 2024-25 Protein Powder Category Report. Clean Label Project.
• Quality assurance issues in the use of dietary supplements, with special reference to protein supplements. J Nutr. 
• Dietary protein recommendations and the prevention of sarcopenia. Curr Opin Clin Nutr Metab Care.
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• Differential effects of protein quality on postprandial lipemia in response to a fat-rich meal in type 2 diabetes: comparison of whey, casein, gluten, and cod protein. Am J Clin Nutr.
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• Pregnancy Nutrition: Healthy Eating While Pregnant. American Pregnancy Association.
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• Effects of soy protein and isoflavones on circulating hormone concentrations in pre- and post-menopausal women: a systematic review and meta-analysis. Hum Reprod Update.