Study: Polyester Underwear Lowers Sperm Counts, Atrophies Testicles, and Decreases Sexual Desire

Sperm count underwear

Sperm - EndAllDiseaseAccording to a study in 2003, average sperm counts have dropped 50 percent worldwide since World War II, and the World Health Organization reports up to 12 percent of couples with women of childbearing age are infertile.

Studies show environmental chemicals are one contributor to the epidemic of infertility, and now we have strong evidence that synthetic underwear is also to blame.

Study #1: Underwear Causes Lowered Sperm Counts & Shrunken Testicles

In a 1993 study, published in the medical journal Urological Research, researchers compared the effects of polyester underwear to cotton underwear by putting loose-fitting polyester underpants on a group of male dogs, and loose-fitting cotton underpants on another group of male dogs. Over a period of 24 months, the researchers examined their semen quality, testicular temperature, hormones, and testicular biopsies of the dogs.

While dogs outfitted with cotton undergarments experienced no reproductive side effects, degeneration of the testes and “significant decreases” in the sperm counts for all dogs were found in the group wearing polyester undergarments.

What was it about the polyester underwear that affected fertility in the male dogs?
The medical researchers concluded: “It may be assumed that the electrostatic potentials generated by the polyester fabric play a role.” It was the electrostatic charge generated around the crotch area by the polyester fabric that caused the side effects.

Study #2: Underwear Causes Reduced Sexual Desire and Frequency

infertile_man_clinical_evaluationIn a 1996 study, also published in the medical journal Urological Research, fifty men were divided into four groups to measure how sexual desire and the frequency of sexual activity were affected by different types of textile underpants. The four types of underpants that distinguished each group were:

  1. 100% polyester
  2. 50% polyester, 50% cotton
  3. 100% cotton
  4. 100% wool

According to the study, “Sexual behavior was assessed before and after six and twelve months of wearing the pants, and six months after their removal,” and “Behavioral response was rated as potent if the subject’s penis became erect, entered the vagina, and ejaculated. The electrostatic potentials generated on the penis and scrotum were measured by an electrostatic kilovoltmeter.”

The study found “significantly reduced” sexual desire and sexual activity in the men who wore 100% polyester and the polyester-cotton mix underpants. “The polyester-containing pants generated electrostatic potentials, which may induce electrostatic fields in the intrapenile structures and could explain the diminished sexual activity. The cotton and wool textiles did not generate electrostatic potentials. Thus, polyester underpants could have an injurious effect on human sexual activity.”

Chemical Dangers from Underwear

An estimated 8000 chemicals are used to transform raw materials into fabric. “Often, the clippings from fabric mills are so loaded with dangerous chemicals they are handled like toxic waste,” stated German Chemist Michael Braungart in the book Killer Clothes.

The genital area is the most sensitive part of the human body for chemical absorption. In addition to the electrostatic charge from polyester contributing to infertility, wearing underwear made of fabric that is not organic means your genitals are being directly exposed to a multitude of toxic chemicals.

Chemists Arlene Blum and Bruce Ames from University of California have stated that the scrotum is “about twenty times more permeable to chemicals than is other skin.”

A New York University Medical School professor concurred in a December 1989 article when he wrote in Cutis medical journal stating: “The scrotum muse be recognized as a skin area with remarkable permeability. It provides a unique percutaneous doorway for the entrance of drugs into the circulation and is thus uniquely susceptible to toxic and irritant agents.”

Which chemicals is your scrotum being exposed to when wearing conventional cotton underwear?

Chemicals Added to Produce Conventional Fabric

  • Heavy Metals
  • Softeners
  • Bleaches
  • Harsh Petroleum Scours
  • Ammonia
  • Chemical Dyes
  • Flame Retardants
  • Formaldehyde

The Solution: Organic Cotton Underwear

After researching the dangers of synthetic underwear, I knew immediately that the only option for me was to switch all of my 50% polyester/50% cotton underwear to 100% organic cotton.


1. Shafik, A. Effect of different types of textile fabric on spermatogenesis: an experimental study. Urology Res. 1993;21:367-70.
2. Shafik, A. Effect of different types of textiles on male sexual activity. Archives of Androl. Sep-Oct. 1996;37:111-5.
3. Clement, R. Brian, Clement, Maria Anna, Killer Clothes: How Seemingly Innocent Clothing Choices Endanger your Health. 2011.