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Whey protein and male fertility

Whey is a primary protein found in dairy products, which contains substantial levels of amino acids. Whey protein can be processed into a powder and added to food or drink to boost protein consumption and benefit muscle growth, weight loss, or athletic performance.

Though consuming whey is a convenient method of increasing your daily intake of protein, some research shows whey powders and supplements may have a negative impact on male fertility when such products contain harmful ingredients like anabolic steroids. Here is what you should know about whey protein’s effects on male fertility, and other protein-packed alternatives to consider.


  • Whey is a primary protein found in dairy products and contains substantial levels of amino acids.
  • While whey protein powders and supplements can help users increase their daily protein intake, research is mixed on how they affect male fertility.
  • Some whey protein powders and supplements contain harmful ingredients like anabolic steroids, which lower sperm count and concentration.
  • Healthier alternatives to whey protein include lean proteins like poultry and fish.

Why do people use whey protein?

Proteins are made up of “building blocks” called amino acids. Our bodies produce amino acids naturally, except for what are known as “essential” amino acids, which must come from our diet. These amino acids serve a number of functions in the body, including building muscle and creating new immune cells.

Whey protein is known as a complete protein because it contains all nine essential amino acids. Studies show that consuming whey protein can help increase muscle mass, speed muscle recovery, and aid weight loss. This makes whey protein appealing for bodybuilders, athletes, or anyone looking for a nutritional boost.

Does whey protein consumption affect male fertility?

Though there are nutritional benefits to consuming whey protein, some research suggests that some powders and supplements may have a negative impact on male fertility. This is especially true when whey protein products contain harmful ingredients like anabolic steroids.

How whey protein affects male fertility

When it comes to how whey protein affects male fertility, research is mixed. A 2020 animal study showed that the highest recommended human dose of whey protein supplementation did not significantly impair the sperm quality or fertility in male mice. An earlier study of 40 male gym-goers found the same in humans, while also noting an increase in motile sperm by those who consumed whey protein supplements.

Gynecologist Sarah Martins Da Silva, of the University of Dundee, told The Sun in 2018 that steroid derivatives in protein shakes may affect testosterone “and therefore sperm production.” However, a 2019 study by the University of South Australia found that consuming high-protein, low-fat foods like whey protein and egg whites naturally improved testosterone levels for obese men with hormone imbalance, potentially also enhancing fertility.

However, not all powders and supplements are created equally, and unfortunately protein powders and supplements are not well regulated. When whey protein powders and supplements contain harmful ingredients, there can be adverse effects on reproductive health.

Harmful ingredients in protein powders and supplements

Though whey protein is generally safe, many powders and supplements contain ingredients that may be harmful when it comes to male fertility. And some of those ingredients may not be listed on the label.

For instance, a 2015 study showed that 23 out of 24 dietary supplements available in fitness equipment shops contained anabolic steroids (synthetic testosterone). Because anabolic steroids disrupt the balance of testosterone and other male fertility hormones, use of steroids can cause decreased sperm quality and low sperm count. A 2019 study found that when subfertile men abstained from taking protein supplements, they had a significant increase in median sperm concentration.

Other ingredients commonly found in whey protein powders and supplements that may be detrimental to health include artificial sweeteners and added sugars. Researchers have found a correlation between excessive sugar intake and low sperm motility. Some whey protein supplements contain stevia instead, which is thought to be safer because it is a natural sweetener. However, animal studies suggest an association between stevia consumption and impaired fertility.

Losing weight for male fertility

Many choose whey protein or whey-based products to help with weight loss. High-protein diets may help people lose excess weight because they’ll feel fuller longer, be less likely to snack, and build and maintain more muscle mass.

Being overweight or obese has been associated in research with lower sperm count and decreased motility. A 2016 study assessed male partners in subfertile couples, classifying them into four categories: underweight, normal, overweight, and obese. Researchers concluded that sperm quality, concentration, count, and motility were all slightly lower in overweight and obese participants than in those with normal weight. Additionally, rates of oligospermia (low sperm count) and azoospermia (sperm count of zero) were more prevalent among obese patients, compared with normal weight men.

For men with a high body mass index, losing weight has been shown to be associated with improved semen parameters and hormonal profiles. We know that, for those who are overweight, losing weight can help improve fertility. However, whey protein may not be the best way to increase your protein intake for weight loss.

Why lean proteins are more beneficial

To avoid the harmful effects of hidden ingredients in whey protein powders and supplements, it may be beneficial to explore other sources of the nine essential amino acids. The following foods are complete proteins:

  • Fish
  • Poultry
  • Eggs
  • Beef
  • Pork
  • Dairy
  • Some grains like quinoa and buckwheat

Some of these proteins, such as fish and poultry, have additional positive effects on male fertility:

  • Fish: Those who consume white meat fish, like cod or halibut, have higher sperm quality, according to one study. Eating fatty fish like salmon, bluefish, or tuna has been shown to increase sperm count. Fish and eggs are also significant sources of vitamin B12; a literature review suggests that B12 may reduce oxidative stress on sperm and decrease inflammation-induced semen impairment.
  • Poultry: In a 2015 study, researchers found that while processed meat intake was inversely related to fertilization rate in conventional IVF cycles, men who mostly ate poultry had a 13% higher fertilization rate.

The bottom line: Whey protein powders may not be the best choice if you’re trying to conceive or are concerned about your fertility.

Though whey protein supplements and powders may boost your athletic performance and increase your muscle mass and strength, these products should be avoided if you are trying to conceive. Protein powders are not regulated by the FDA, and while they are periodically tested, some products may fly under the radar, especially when they are sold online.

Following a healthy diet of lean proteins, whole fruits and vegetables, and unprocessed foods is a better way to support an active lifestyle as well as your reproductive health. Explore superfoods for male fertility and check out our comprehensive guide to sperm improvement for more tips.

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