Microplastics and Testosterone: They Found Plastic in Every Human Testicle They Checked

Researchers tested human testicles for microplastics. Every single one had them.

That is not a headline I made up. It is the result of a 2024 study, and it is not the only one.

What they found in men

• Testicles. Microplastics were present in all 47 dog and 23 human testes examined. The human average was 328 micrograms per gram of tissue, almost three times the level in dogs. Polyethylene was the main type. (Hu 2024)
• Semen. A Chinese team detected microplastics in both testis and semen samples, the first report of plastic in the human male reproductive system. (Zhao 2023)
• Sperm quality. In 113 men from three regions of China, microplastics were found in every semen and urine sample. Each additional type of plastic a man carried was linked to a lower total sperm count, lower concentration and lower motility. (Zhang 2024)

In the testis study, certain plastics, such as PVC and PET, were associated with lower testis weight.

What about testosterone?

Here the evidence comes from animals.

Mice drank water containing polystyrene microplastics for 180 days, at levels the authors describe as environmental. Their testosterone, LH and FSH all fell. Sperm viability dropped and abnormal sperm increased. (Jin 2022)

The mechanism the authors traced was a weaker LH signal to the testicle, which lowered the proteins that carry cholesterol into the cell to be turned into testosterone.

The honest part

No study has shown that microplastics lower testosterone in men. The human studies prove the plastic is there, and they show correlations with sperm quality. Correlation is not cause. The testosterone result is from mice.

So the fair summary is this: plastic reaches the testicle, it tracks with worse sperm in men, and it lowers testosterone in mice. Nobody knows yet how much of that carries over.

What I do about it

You cannot avoid microplastics completely. I think you can lower the load, and you can make your body harder to hurt.

• I do not heat food in plastic or drink hot drinks from plastic cups.
• I use glass or steel for water.
• I do not handle paper receipts. They carry a different plastic chemical. See BPA vs BPS.
• I keep my metabolic rate high. In my view a body with strong thyroid function and a liver that is well supplied with sugar clears foreign material better. That part is my opinion, not a study result.

For the other things that raise and lower androgens, read How to increase DHT.

Quick answers

Do microplastics lower testosterone?

In mice, yes: 180 days of polystyrene microplastics in drinking water lowered testosterone, LH and FSH. In men it has not been shown. Human studies so far show that microplastics are present in testicles and semen and correlate with lower sperm quality.

Are there microplastics in human testicles?

Yes. A 2024 study found microplastics in every human testis it examined, at an average of 328 micrograms per gram of tissue.

Do microplastics affect fertility?

In a study of 113 Chinese men, each additional type of microplastic found in the body was associated with a lower sperm count, concentration and motility. This is an association, not proof of cause.