Fabrics and Fertility

Recently I was forwarded an interesting article from Sayer Ji’s Substack from August 8, 2025, regarding the impact of fabrics on fertility. Probably due to a certain amount f suppression by the fabric industry, not much of it has made it to light as yet. So here’s the deal:

62% of all fabric worldwide are synthetic. For all intents and purposes, synthetic fabrics are basically various forms of plastic spun into thread.

As you may know, the skin, your skin, is a permeable membrane. Everything you put on your skin eventually ends up in your blood stream. Consider, as many fertility patients know, the use skin patches as a medical delivery system. Many medications are delivered into the body via the skin as in estrogen patches, hormonal creams, and pain management medications. (Think Fentanyl patches, for example.)

This is an issue for both men and women. In men, underwear made of synthetic material have caused grave concerns for fertility. In one study in 1992, Dr. Ahmed Shafik had 14 men, (yes I know, small sample size) who were trying to conceive with fertile women, wear a “scrotal sling” made of polyester resembling a pair of polyester briefs. After 5 months, NONE of the female partners were pregnant. Part of the explanation for this may be that the sling carried the testicles too close to the body, so scrotal temperature went up. (Obviously briefs are hotter than boxers.) Another issue is the that the polyester apparently leached environmental toxins into the seminal fluid and sperm. Microplastics have been actually found in testicular tissue. Also, some research has shown that synthetic underwear sets up an electrostatic charge that is detrimental to sperm.

Further, for women, plolyester underwear can cause difficulty in conception due to many of the same reasons. Yoga pants, popular and comfortable, are usually made from synthetics which have BPAs and PFAs, endocrine disruptors which can contribute to polycystic ovarian syndrome and recurrent pregnancy loss. BPAs are the “forever chemicals” that you may have heard about. BPAs and microplastics have been found in placenta tissue.

With all of this said, we can reduce it to a couple of easy instructions. Women, find underwear and yoga pants made from natural fabric. Cotton, pure silk, or bamboo are good options. For men, ditch those stretch briefs and move to natural fabric boxers. Again, cotton and bamboo are good options. Hemp is also good, but requires several washings to be really comfortable.

There are other concerns about synthetic fabrics also. To quote Sayer Ji’s article,

“While Dr. Shafik's subjects recovered their fertility after removing polyester, we're now learning that chemical exposures don't always leave without a trace. Recent groundbreaking research has shown that body cells can transfer genetic information directly to sperm cells—no sexual reproduction required. This means that environmental toxins affecting any part of your

body could potentially alter the genetic information in your sperm, passing changes to future generations32. This discovery, published in peer-reviewed journals, reveals that harmful exposures might cause subclinical damage and epigenetic changes that persist even after the initial threat is removed.

The implications are sobering: those polyester underwear might not just temporarily suppress your sperm count—they could potentially be altering genetic information that gets passed to your children. While full fertility might return, the epigenetic legacy of synthetic fabric exposure could linger in ways we're only beginning to understand. This makes the case for natural fibers even more compelling—it's not just about your fertility today, but about the genetic health you're passing forward.”