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How Does Milk Affect Your Testosterone Levels?

Testosterone is the king of male hormones. When your levels are optimized you’ll feel strong and confident, athletic and dominating.

Make the right diet and lifestyle choices and your hormone levels will soar. Make the wrong choices and you’ll be digging yourself into an ever-deeper hole of belly fat and weakness.

One such food that’s always in the limelight when you research muscle building nutrition is milk – a food with the sole purpose of developing and sustaining health in newborn animals.

But what are the effects of milk on testosterone levels?

In this article we take a look…

What is Milk?

Milk is  obtained from the breast of non-human animals and is one of the most popular  and nutritious foods available. We drink over 750 million tonnes per year [1] and that figure is ever-growing.

We use it to make cheese, cream, yogurt and butter and dairy products make up a large proportion of many government healthy eating guidelines.

It has a complex nutrient composition that can help to serve a number of important function in the human body too.

Nutrient value

Because milk is designed to develop and sustain the health of newborn cows, it is packed full of nutrients.

Whole milk has a high fat content of around 4%, whereas a reduced fat variety is only around 1%. The fats are mostly saturated and composed heavily from triglycerides and the fatty acids lauric, myristic and palmitic acid.

In total there are over 350 different fatty acids in milk, making it complex in structure.

The carbohydrate content of the food is mainly made up of the lactose – a disaccharide made up of glucose and galactose and it is high in protein and branch chain amino acids (BCAAs) too.

Many dairy foods are also fortified with additional nutrients such as vitamin A and the testosterone-boosting vitamin D. However, even enriched milk only contains 65% of your daily vitamin D need. As vitamin A and D are fat soluble, the lower the fat of the food, the less of these important vitamins you’ll get from it.

You’ll also find a decent hit of calcium as well as modest amounts of potassium, riboflavin, phosphorous and vitamin B12 in this food too.

Key point: At face value, this dairy food is as near to a super food as you’ll get. Not only is there an abundance of macro and micro nutrients, but they are all in a favourable ratio too.

Build Muscle with Milk

The high protein content of milk makes it a great food for building muscle. It provides both soluble and insoluble protein which are more commonly known as whey and casein.

Whey is a great source of BCAAs and increases protein metabolism quickly. These protein building blocks are key to stimulating muscle protein synthesis [2]. Leucine – the most abundant BCAA found in the food – directly initiates the early cellular process of muscle building.

The other protein found in milk, casein, improves overnight recovery and protein metabolism. This means you’ll regenerate more protein cells throughout the night [3]. It digests much slower which means it provides a much more sustained release of BCAAs throughout the night.

Both of these groups of proteins are excellent quality, with good digestibility and a high proportion of essential amino acids.

If you’re looking to add muscle mass then milk is a great food to add to your diet.

Dairy Can Help You Lose Fat

There are a number of studies that show dairy products can help improve body composition.

A study based at McMaster University [4] tested the effects of milk on 3 groups of young men who were taking part in a 12-week exercise program, 5-days per week. After each workout, the volunteers were given either:

  • Skimmed milk
  • A soy drink
  • A carbohydrate drink

The group that ingested skimmed milk had much higher protein synthesis than the other two groups, which resulted in better lean muscle levels. They also lost twice as much fat as the other groups – 2lb.

An interesting study published in Obesity Research [5] found that even when not in a calorie deficit, a high dairy diet could help you lose fat mass.

In the study, 34 volunteers were given the same amount of calories, with one containing 500 mg per day of dairy food and the other containing 1,200 mg.

The amount of calories in each diet wasn’t only the same, but purposely chosen to so that it didn’t restrict energy – it was based on weight maintenance.

Although neither group lost any weight, the higher dairy group reported a 2.16 kg loss of fat mass, 1 kg of which was from the abdominal area.

Key point: Milk stimulates protein synthesis which speeds up muscle building. It can also help you reduce fat mass and improve body composition.

Can Milk Decrease Testosterone?

In order to optimize milk production, cattle are kept pregnant as often as possible, meaning a greater yield of milk. The process is relentless but productive.

As a food with the sole intention of providing nourishment for growth and development, you’d expect to find some active hormones in it. And you will – nearly 50 hormones in total.

According to research, milk typically contains growth hormone, prolactin, glucocorticoids, androgens and the female sex hormones, estrogens [6].

So your milk may well contain testosterone, but it will probably also contain the female hormone estrogen. It makes sense then that if these hormones could leach into the milk, you’d absorb them.


A research paper from 2010 detailed the effects of milk hormones in humans [7].

In the study, a small selection of male, female and child volunteers were asked to drink approximately 16 oz of cow’s milk. Their blood was then tested every 15 minutes afterwards for 2 hours.

Levels of the female hormones estrone and progesterone significantly increased. Testosterone levels went the other way – they significantly dropped, as did GnRH – a trigger hormone that stimulates testosterone development.

But how much does milk contribute to estrogen levels anyway?

The answer is potentially quite a lot.

Another study, this time published in Medical Hyptheses [8], investigated exactly how much of the human exposure to estrogen milk was responsible for.

The research team stated that they were concerned with the levels of female sex hormones in milk, and rightly so. They found that the dairy product was responsible for as much as 60-70% of all estrogens consumed.

The study went on to suggest that modern processing methods that allow cows to lactate during the latter half of pregnancy are resulting in more estrogens passing into milk than ever before.

The milk that we now consume may be quite unlike that consumed 100 years ago [8]


Milk is a nutritious food responsible for health and development of newborn animals. It has a high protein and fat content that is useful for anyone wanting to build muscle or lose body fat.

It does contain a worrying amount of female sex hormone which may affect your testosterone levels. For that reason you may want to be cautious not to over-consume it.

Does this mean that you should ditch the dairy altogether? No of course not. It provides a highly efficient source of nutrients. In combination with regular strength exercise, good food choices and effective T-boosting nutrients, drinking milk in moderation isn’t going to cause much damage.

However if you’re wanting to focus on the absolute minutiae of testosterone production then it may be a food to limit or even eliminate from your diet altogether.


  1. Food Outlook. Global Market Analysis. 2012: 1-117
  2. Tipton, KD et al. Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise. Am J Physiol Endocrinol Metab. 2007; 292(1): E71-6
  3. Res, PT et al. Protein ingestion before sleep improves postexercise overnight recovery. Med Sci Sports Exerc. 2012; 44(8): 1560-9
  4. Hartman, JW et al. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr. 2007; 86(2): 373-381
  5. Zemel, MB et al. Effects of calcium and dairy on body composition and weight loss in African-American adults Obes Res. 2005; 13(7): 1218-25.
  6. Jouan, PN et al. Hormones in bovine milk and milk products: A survey. Int Dairy J. 2006; 16(11): 1408-1414
  7. Maruyama, K et al. Exposure to exogenous estrogen through intake of commercial milk produced from pregnant cows. Pediatrics Int. 2010; 52(1): 33-38
  8. Ganmaa, D et al. Is milk responsible for male reproductive disorders?. Med Hypotheses. 2001; 57(4): 510-4