Are Protein Powders Safe to Take Long-Term?

Even if we lived in a world bereft of statistical evidence, the anecdotal cues would be enough to clue you into the fact that protein powders are among the most popular nutritional supplements in the world. 

If you took the most shallow of historical dives, you’d notice that protein powders were the first serious supplements to become popular with the gymgoing crowd, and also amongst serious athletes. If you started going to the gym in the 1980s or 1990s, you probably noticed how protein powders were the first supplements being sold directly inside of the gyms, with major chains like Bally Total Fitness selling self-branded protein powders to members inside of their facilities.

Outside of this historical context of protein powder, it’s also easy to gauge the popularity of protein powder from its impressive variety. Supplement-makers wouldn’t go out of their way to produce so many options of a product for which there was no market. Yet, aside from the original offerings of whey and soy protein, several other powdered protein alternatives have sprouted up. 

Whether you prefer protein powder that’s formulated from protein-packed staples like yellow peas, or you want something more exotic or seasonal like hemp or pumpkin, there is a protein powder to accommodate seemingly every craving.

Your instincts are correct; the global protein powder market sits at approximately $26 billion and is steadily rising. The reason for this popularity is twofold: Protein is essential for health, and protein powder works. While the recommended range of protein intake can vary based on the last dietitian or nutrition expert you consulted with, protein remains essential for the maintenance and growth of muscle and other body tissues. 

This perceived dependence on protein leads to an obvious concern: Is protein powder safe to take on a daily basis for many years in succession? That answer to this question is both simple and complex, because it depends on the type of protein powder you’re consuming, the safety of that protein powder with respect to both its source and its preparation, and then the quantity of protein powder you’ve consumed that might not be as healthy as you initially believed.

Safety of Daily, Long-Term Protein Powder Intake

Fortunately for you, there is nothing inherently wrong with protein powder supplementation for extended periods of time, and for a very good reason. At its essence, protein powder is simply a refined form of a natural food with some of its situationally undesired traits stripped away. 

Or, to offer a clear example, pea protein powder usually consists primarily of yellow peas that have had their ample carbohydrate content stripped away, leaving almost exclusively the protein content of the peas remaining. This elimination of the peas’ carbohydrate content allows you to amplify only your protein content without experiencing the undesired caloric boost that would occur if the carbohydrate content was permitted to remain.

Similarly, the creation of whey protein powder from its original milk source — even a low-fat form of milk like 2% milk — separates the whey protein powder from an immense number of calories. For instance, a single cup of 2% milk provides 8 grams of protein, 12 grams of carbohydrates, and 5 grams of fat, meaning that approximately 75 percent of the milk’s calories comes from non-protein sources.

By way of extrapolation, a 28-gram dose of Transparent Labs grass-fed whey protein powder, which contains 3.5 times the protein of a serving of 2% milk, only has 140 calories, and 80 percent of the overall caloric content comes from protein. To consume an equivalent amount of protein from 2% milk, you would have to drink more than 450 calories, resulting in the consumption of more than 300 unnecessary calories.

Moreover, by separating the protein from its whole-food source, it can reduce the occurrence of allergic reactions resulting from the consumption of certain allergens. For instance, the refining process of some whey protein powders filters out the lactose, making it tolerable to people who otherwise suffer from lactose intolerance.

Muscle Maintenance

Plenty of research has been conducted that has proven how protein powder has been an integral part of many nutrition programs that have accelerated the growth of lean muscle and boosted strength. This has been especially obvious when the intake of protein powder has accompanied an exercise program that features resistance training and progressive overload.

A meta-analysis of studies clearly shows that increases in lean muscle mass and strength are experienced by test subjects who have already engaged in resistance training and are otherwise healthy whether they’re older or younger than the age of 65. (1) In addition, the preponderance of the evidence demonstrates that protein consumption also accelerates improvements in both aerobic and anaerobic power. (2)

Satiety

One of the underrated benefits of protein — particularly in the context of a scenario where your body would benefit from a reduction in calories — is the increased feeling of satiety that accompanies protein consumption.

There are two primary causes for these feelings of satiety. First, protein takes a longer time for your body to digest than fats and carbohydrates, which lengthens the periods of time in between cravings, resulting in fewer instances of hunger pangs. 

Second, protein intake floods your body with amino acids, which trigger the release of specific satiety hormones in your brain, which elicit feelings of satisfaction. Because of this, you are less likely to reach for food out of a sense of felt need if you are regularly consuming protein. 

As an added bonus, protein has a much higher thermic effect than carbohydrates and fats, which simply means that your body uses more energy to digest protein than it does to digest the other macronutrients. Therefore, not only is the intake of protein powder likely to lead to fewer instances of overeating, but it also leads to a higher percentage of your calories from food being burned without conscious effort.

Convenience

Dropping 25 or more grams of protein powder into a shaker bottle and drinking it down enables you to consume an entire meal’s worth of high-quality protein content in mere seconds. Over the course of a work day, this can transform a one-hour lunch break into an almost imperceptible two-minute delay, allowing you to maintain your productivity as you turn aside your urge to eat foods that might be unhealthy.

In a training setting, a shake made from protein powder can grant your body instant access to the amino acids that it requires to repair the damage caused by your workout, allowing you to maximize the benefits of your workout, and eliminating any possibility that you might forget to give your muscles access to the nutrients they require to capitalize on all of your hard work.

For what it’s worth, a 2023 meta-analysis of eligible studies that factored the timing of protein ingestion into their consideration found that protein intake either shortly before or after exercise was the most productive time to consume protein for the purpose of muscle growth, while protein intake at night seemed to be more directly correlated with protein-supported improvements in strength. (3)

Potential Concerns

While there are several myths connected with the consumption of protein powder, and with protein in general, some of the concerns around protein powder are rooted in at least some semblance of fact. However, most of these causes for concern are built around easily diagnosable matters that can be easily overcome with a few modifications in behavior and protein powder selection as opposed to outright avoidance of protein powder.

Digestive Issues

The consumption of protein powders can lead to digestive issues that usually stem from a consumer’s sensitivity to the specific source of protein in question. For instance, someone who is lactose intolerant may be somewhat sensitive to a whey protein powder that hasn’t had its lactose filtered out, and someone with actual allergies to dairy may have to avoid milk-derived protein powders altogether. 

Fortunately, the supplement industry has adapted to such an extent that even people who experience allergic reactions or gut discomfort from milk-based proteins can get easy access to an organic vegan protein powder that is formulated to administer a complete dose of amino acids on par with that of whey or casein protein powder, and without the digestive discomfort.

Quality and Regulation

Many of the problems with protein powders stem from the dishonesty of the manufacturer. These opportunities are made possible due to a lack of FDA regulation for supplements, which is not on par with that of whole food. The result is that some supplement companies will resort to disreputable tactics to shield the inferiority of their products while they mislead consumers.

For example, some supplement-makers will attempt to game the system by resorting to methods like nitrogen spiking, which artificially inflate the nitrogen content of the protein so that it tests at a higher protein level than is actually present in the container. One of the ways to avoid this is to look for supplements that have had their contents verified by reputable third-party authenticators that can certify the supplements as valid.

Risks of Poor Quality Protein Powders

Another matter entirely is the problem posed by protein powders that contain unhealthy ingredients, or that are created in facilities with poor quality controls that permit contaminants to find their way into the final product.

For example, the majority of protein powders contain unnatural colors, artificial sweeteners, unnecessary fillers and preservatives, and other ingredients that have been proven to have harmful effects on the human body. Testing has revealed how these ingredients can cause digestive discomfort, cognitive problems, and other issues.

While these ingredients can be accounted for, others cannot. Third-party testing has indicated that the overwhelming majority of popular protein powders tested positive for unacceptable quantities of lead, and other heavy metals and toxic ingredients. 

Therefore, unless your protein powder has its contents verified, along with some form of testing for harmful ingredients that are not identified on its label, you may be exposing yourself to hidden dangers that only increase if you engage in the long-term consumption of an unsafe protein powder.

Overconsumption

The adaptability of your body with respect to its ability to consume copious amounts of protein is a contentious matter. This stems from the fact that there is an ongoing debate with respect to how much protein your body can consume during a standard meal’s worth of time, and also how much protein your body can tolerate without experiencing self-imposed stress.

To begin with, there is evidence that consuming large quantities of whey protein has effects on renal function even in healthy individuals, but there is ongoing debate as to whether or not it is simply a harmless individual adaptation to the presence of high protein. At the moment, any negative response to ingesting high levels of whey protein seems to be reserved for those who persist in a sedentary lifestyle while undertaking a high protein diet. (4)

Meanwhile, the same high levels of protein consumption have seemed to have beneficial effects on intestinal microbiota while working in favor of boosting muscle mass, even in elderly populations. (4) 

Of course, since any concerns about diminished renal function seem to be centered around the use of animal proteins, switching to a plant-based protein powder like pea protein isolate can immediately eliminate any perceived problems.

Do You Need to Take Breaks?

The belief that cycling on and off protein supplements is not only beneficial but essential to maximize the benefits of protein powder seems to be a misunderstanding that stems from the use of anabolic steroids and other chemical interventions used by bodybuilders and others who directly manipulate their hormone levels to achieve results at a potentially dangerous cost.

Because the process of artificially causing testosterone levels to surge can shut down the natural production of testosterone, people who take testosterone boosters regularly cycle themselves off of those chemical enhancers in order to preserve their body’s ability to create its own testosterone.

None of these concerns are present with respect to protein consumption. Again, because your body perceives protein powder as food — because it is — there is no greater need to cycle off of protein powder than there is to cycle off of milk, chicken, eggs, cheese, peas, or any other high-quality sources of protein. 

What this means is that there is no need to seasonally alter your daily protein requirements on the basis of your body’s ability to process it, especially due to the unfounded belief that ingesting protein at high levels for long periods of time will inhibit your ability to process it beyond a certain threshold or timetable.

How to Choose a Safe Protein Powder for Long-Term Use

With all of this information at hand, you are now free to select a protein based on information that is rooted in face. As such, here are the factors that you should use to help you identify which protein powders are suitable for long-term use.

Look for Third-party Testing and Transparency

Thankfully, there are multiple certifying marks that supplements seek out to verify the cleanliness and purity of their products. This includes the NSF’s “Certified for Sport” third-party certification program, which verifies that a product does not contain “unsafe levels of contaminants, prohibited substances or masking agents, and that what is on the label matches what is in the product.”

This also applies to the Informed Sport certification, which confirms the cleanliness of supplements both before and after their initial approval process. Once a supplements manufacturing process is reviewed and approved, and a sample has been decreed to be contaminant-free, the verified supplement becomes subject to regular blind testing in order to ensure that the product remains in compliance with the Informed certification requirements.

Certifications aside, the most helpful item that a supplement-maker can present you with for verifying the cleanliness of its products is a certificate of analysis from an independent testing authority. 

A COA not only authenticates the macronutrient and caloric content on the container, but it also reveal the levels of lead, mercury, arsenic, cadmium, and other toxic metals that may be present in the protein powder, along with undesirable microbes like yeast or salmonella. When this level of transparency is working in your favor, you know you’re making a fully informed decision.

Search for High Ingredient Quality

While it’s clearly beneficial to ensure that there are no toxic impurities lurking within your supplements, it’s also ideal if your protein powder is made of all-natural ingredients, and is free of artificial sweeteners, colors, or preservatives. 

This is an underrated element of your quest to remain healthy throughout your long-term use of protein powder, because protein powder may be harmless to consume when it’s in a pristine form, but many protein powders are loaded with ingredients that have been proven to cause harm when consumed with regularity.

The type and severity of these problems varies widely, from neurobehavioral effects like hyperactivity to unhealthy changes in the gut microbiome, to  cardiovascular disease. (5) (6) (7) Theoretically, it could be truthfully stated that it’s only safe to take protein powder on a long-term basis as long as the protein powder formulation is safe in and of itself. 

Select the Right Protein to Suit Personal Needs

Your days of only being permitted to choose between whey and soy protein are long behind you. Nowadays, you can choose from amongst a dozen varieties of protein powder. With that being said, some protein powders are more effective than others, which has resulted in a handful of protein powders rising to prominence due to their efficiency and reliability, combined with other traits that align with the personal needs of targeted groups of consumers.

For example, while whey protein powder is the standard by which all other protein powders are judged due to its overall effectiveness at building muscle by rapidly spiking amino acid levels, the slower digestion of casein protein makes it an ideal protein powder for nighttime consumption because it is known to prevent catabolism, or breakdown. 

On the other hand, if you suffer from a dairy allergy and are unable to consume either whey or casein due to their dairy derived natures — or if you simply don’t consume animal-based products because of your lifestyle choices — modern vegan protein powders have been formulated to compete favorably with the amino acid ratios of whey and casein protein. 

What all of this ultimately means is that you can now allow your personal needs to play a role in dictating the variety of protein you consume without compromising your outcomes with respect to lean muscle growth, strength gains, and commensurate decreases in unwanted body fat.

Practical Guidelines for Readers

If you’re going to set yourself on a path to long-term success with protein powder as a central feature of your nutrition plan, it’s ideal to have some healthy guidelines in place for its use. This starts with acknowledging the healthy ranges of protein intake for your size, goals, and circumstances.

The present guidance for minimum protein intake for a healthy adult to prevent deficiency is 0.8 grams of protein per kilogram of body weight. Therefore, a 170-pound person (77 kg) would require about 62 grams of protein to avoid deficiency, whereas a 200-pound person (90 kg) would require 72 grams of protein to accomplish the same goal. 

Then again, for athletes, physically active individuals, or older adults, the guidance typically shifts to 1.2 to 1.6 grams of protein per kilogram of body weight. Still, similar studies have shown that active individuals are able to tolerate daily protein intake as high as 2.2 grams per kilogram. (8)

In order to achieve dietary goals that require the sustained ingestion of 100 grams of protein or more on a daily basis, you are advised to use a mixture of whole food and supplemental protein sources. By averaging 20 or more grams of protein across five meals, snacks, and supplemental protein sources each day, it can considerably simplify the process of meeting protein intake goals. 

As such, protein powder becomes an easily consumed complement to the protein you consume from snacks and meals, possibly boosting your daily protein intake by 50 percent or more with a single scoop.

With this being said, if you have any pre-existing health conditions that might be exacerbated by high protein intake, like kidney disease or other kidney-related issues, you should definitely consult with a physician before adopting a high-protein dietary strategy. (9)

Healthy Protein; Healthy Body

The truth is that for most people, protein powders are perfectly safe to consume as a long-term part of your nutrition plan. The key is to ensure that your protein powder is inherently healthy. To that end, you are advised to avail yourself of one of the protein powders offered by Transparent Labs, which are sourced from clean farms, processed and packaged in clean facilities, and certified by reputable third-parties. This way, by starting with a clean, healthy protein source, the health of your body will never be in question.

Sources:

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2. Pasiakos SM, McLellan TM, Lieberman HR. The effects of protein supplements on muscle mass, strength, and aerobic and anaerobic power in healthy adults: a systematic review. Sports Med. 2015 Jan;45(1):111-31. doi: 10.1007/s40279-014-0242-2. PMID: 25169440.

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5. Miller MD, Steinmaus C, Golub MS, Castorina R, Thilakartne R, Bradman A, Marty MA. Potential impacts of synthetic food dyes on activity and attention in children: a review of the human and animal evidence. Environ Health. 2022 Apr 29;21(1):45. doi: 10.1186/s12940-022-00849-9. PMID: 35484553; PMCID: PMC9052604.

6. Seto T, Grondin JA, Khan WI. Food Additives: Emerging Detrimental Roles on Gut Health. FASEB J. 2025 Jul 15;39(13):e70810. doi: 10.1096/fj.202500737R. PMID: 40622070; PMCID: PMC12232514.

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9. Ko GJ, Rhee CM, Kalantar-Zadeh K, Joshi S. The Effects of High-Protein Diets on Kidney Health and Longevity. J Am Soc Nephrol. 2020 Aug;31(8):1667-1679. doi: 10.1681/ASN.2020010028. Epub 2020 Jul 15. PMID: 32669325; PMCID: PMC7460905.