Why is whey protein not recommended? Addressing health concerns and dietary downsides

December 4, 2025 •

4 min read

While celebrated for its rapid absorption and muscle-building properties, a 2020 review found less research on whey protein's potential risks, including its effect on the gut microbiome and skin. This raises important questions about why is whey protein not recommended in certain situations.

Quick Summary

This article explores the reasons whey protein may not be suitable for everyone, including digestive issues related to lactose, potential kidney and liver strain with excessive use, hormonal impacts linked to acne, and the risk of nutrient imbalances from over-reliance on supplements. It provides a balanced overview of common concerns and presents alternative options.

Key Points

Digestive Distress: Whey protein's lactose content can cause bloating, gas, and cramps, especially for those with lactose intolerance.
Kidney and Liver Strain: Excessive, long-term intake can put a heavy workload on the kidneys and liver, particularly for people with pre-existing conditions.
Acne Flare-ups: The dairy hormones in whey can increase IGF-1, stimulating sebum production and causing or worsening acne.
Nutrient Imbalance: Over-relying on whey shakes as a meal replacement can lead to deficiencies in essential nutrients found in whole foods.
Additives and Contaminants: Some brands may contain artificial sweeteners, fillers, or heavy metals, which can be harmful.
Unsuitable for Allergies: Individuals with a milk allergy should avoid whey protein entirely to prevent severe allergic reactions.
Best for Targeted Use: Whey is best for targeted, short-term use for specific fitness goals, not as a long-term dietary staple.
Whole Food Alternatives: Natural protein sources like eggs, legumes, and lean meats offer a more complete nutrient profile with fewer risks.

Common reasons whey protein is not recommended

While whey protein is widely used for its benefits in muscle repair and growth, it is not a perfect supplement for all individuals. For some, specific health conditions or dietary choices mean that whey protein is not recommended. Understanding these factors is key to making an informed decision about your protein intake.

Digestive and intolerance issues

One of the most common reasons people experience problems with whey protein is its dairy origin. As a byproduct of cheese-making, whey protein can contain varying levels of lactose, the milk sugar that many people are unable to digest properly. Lactose intolerance is prevalent globally, and for those affected, consuming whey can lead to uncomfortable gastrointestinal side effects.

Bloating and gas: In individuals with lactose intolerance, undigested lactose ferments in the gut, causing gas and abdominal distension.
Stomach cramps and pain: The digestive distress can result in painful cramping and discomfort.
Diarrhea: For some, the fermentation process can lead to loose stools or diarrhea.

Potential kidney and liver concerns

For healthy individuals, moderate intake of whey protein is not typically harmful to the kidneys or liver. However, excessive, long-term use can place a strain on these organs, particularly in individuals with pre-existing conditions. The body metabolizes protein, creating byproducts like urea, which the kidneys must filter. An exceptionally high protein load increases this workload. For those with compromised kidney or liver function, this additional strain can exacerbate existing issues.

Acne and skin problems

For some individuals, especially those with acne-prone skin, whey protein consumption can trigger or worsen breakouts. This is often linked to the dairy-derived hormones in whey, which can elevate insulin-like growth factor 1 (IGF-1). Increased IGF-1 levels can stimulate sebum (oil) production and lead to clogged pores and inflammation, resulting in acne. This hormonal effect makes whey a problematic choice for those trying to maintain clear skin.

Risk of nutrient imbalance

Over-relying on whey protein shakes as a meal replacement can lead to a significant nutrient imbalance. While protein is essential, whole foods offer a broader spectrum of vitamins, minerals, antioxidants, and fiber that supplements lack. Substituting regular, balanced meals with a whey shake can mean missing out on these critical nutrients, which can negatively impact overall health over time.

Presence of additives and heavy metals

Some whey protein products, especially less reputable brands, may contain unnecessary additives, artificial sweeteners, fillers, or even contaminants like heavy metals. Reading the ingredient list and choosing products with third-party testing certification is crucial. These additives can cause gut discomfort or other negative reactions in sensitive individuals.

Whey protein vs. natural protein: A comparison

To better understand why whey is not always the best choice, comparing it with natural protein sources is helpful.


Parameter	Natural Protein Sources (e.g., eggs, chicken, legumes)	Whey Protein Powder (Supplement)
Source	Found naturally in whole foods, offering a complete nutritional package.	A processed, powdered byproduct of cheese-making.
Nutrient Profile	Rich in a wide range of macronutrients, micronutrients, and fiber.	Provides a concentrated dose of protein and amino acids, but lacks the broad nutrient variety of whole foods.
Digestion Speed	Digests more slowly, providing sustained energy and satiety over time.	Absorbs very quickly, making it a fast fuel for post-workout recovery but less ideal for lasting fullness.
Convenience	Requires preparation and cooking, which can be less convenient for an on-the-go lifestyle.	Quick and easy to mix with liquid for an instant protein boost.
Health Impact	Safer for long-term health with a lower risk of overconsumption and associated side effects.	Excessive use can lead to side effects, especially in sensitive individuals.
Cost	Generally more affordable and sustainable for long-term dietary needs.	Can be more expensive, especially for high-quality, reputable brands.

Who should avoid whey protein?

Certain groups of people should consider avoiding or limiting their whey protein intake to prevent adverse health effects:

Individuals with lactose intolerance or a dairy allergy: As a milk derivative, whey can trigger allergic reactions or digestive issues in those sensitive to dairy. Whey isolate or plant-based proteins are better options.
People with pre-existing kidney or liver conditions: Those with compromised organ function should consult a doctor before taking any protein supplements, as high protein intake can worsen their condition.
Those prone to acne: If you notice that your breakouts increase after consuming whey, it may be beneficial to switch to a non-dairy alternative to manage skin health.
Pregnant or breastfeeding women: Due to a lack of sufficient research, it is recommended that pregnant and breastfeeding women avoid whey protein for safety.
People seeking a complete, whole-food diet: If your goal is to get all your nutrients from whole foods, relying on a supplement can lead to dietary deficiencies.

Conclusion

While whey protein is an effective supplement for many, it is not a universal recommendation for everyone. Its dairy origin can cause digestive problems for those with lactose intolerance or allergies, and excessive long-term use may pose risks to kidney and liver health, particularly in individuals with pre-existing conditions. Furthermore, whey has been linked to hormonal changes that can exacerbate acne and, when used as a meal replacement, can lead to nutrient deficiencies. Exploring alternatives like casein or plant-based proteins can provide a safer, more balanced approach for those who find whey unsuitable. Ultimately, a balanced diet based on whole foods remains the most reliable way to meet your protein needs and support overall health. It is crucial to consult a healthcare professional before making significant changes to your dietary supplements, especially if you have any underlying health concerns.

Frequently Asked Questions

Yes, even healthy individuals can experience side effects, particularly if they are lactose intolerant or consume high doses. Digestive issues like bloating, gas, and cramps are common. In some cases, it can also cause or worsen acne.

For healthy individuals, moderate consumption of whey protein does not damage the kidneys. However, excessive, long-term intake can increase the workload on the kidneys, which is a concern for those with pre-existing kidney disease.

For some people, yes. Whey protein can increase levels of IGF-1, a hormone that stimulates sebum (oil) production and can lead to clogged pores and inflammation, triggering acne breakouts.

Excellent alternatives to whey protein include plant-based options like pea protein, brown rice protein, and hemp protein. Other options include casein protein (for those without lactose intolerance), egg white protein, or simply increasing whole food protein sources like eggs, lean meats, and legumes.

To minimize digestive issues, you can try switching from whey concentrate to a whey isolate, which contains less lactose. Alternatively, use non-dairy alternatives, or ensure you are not consuming too much at once. Waiting 30 minutes after a workout before drinking a shake can also help.

It is not recommended to replace whole meals with whey protein shakes. Shakes lack the essential fiber, vitamins, and minerals that a balanced meal provides from whole food sources. Whey protein should be used as a supplement, not a replacement.

There is not enough reliable information to confirm whether whey protein is safe during pregnancy or breastfeeding. It is best to avoid use during this time and consult a doctor.

Look for reputable brands that provide transparency in their sourcing and have third-party testing certifications. These certifications ensure the product is free from heavy metals, contaminants, and banned substances.