True Cellular Formulas Team - December 05, 2023

Polyester Underwear

Unraveling the Potential Impact on Fertility


In the realm of everyday clothing, underwear is an essential yet often overlooked aspect. Particularly, the choice of fabric for underwear has garnered attention due to emerging research. One such material at the center of this debate is polyester, a common fabric in the underwear industry. Recent studies have shed light on an unexpected aspect of polyester underwear: its potential impact on fertility. The revelation that polyester could be an effective, albeit unintentional, form of birth control for men raises significant questions. Furthermore, preliminary research suggests that women might not be immune to its effects. This blog delves into the science behind these claims, exploring how something as simple as the choice of underwear material could have profound implications for reproductive health.

The Science Behind Polyester and Fertility

Polyester, a synthetic fabric, is prized for its durability, resistance to wrinkling, and ease of care, making it a popular choice for underwear. However, its synthetic nature raises concerns regarding its impact on human fertility. A pivotal study that brought this issue to light explored the use of polyester as a male contraceptive.[1] The study found that wearing polyester underwear could significantly raise the temperature of the scrotum. This increase in temperature is crucial because sperm production, or spermatogenesis, requires a temperature slightly cooler than the average body temperature. Elevated temperatures can lead to a decrease in sperm count and quality, potentially impacting fertility.

Another concern with polyester is its ability to generate a static electrical charge. This static charge is not just a minor annoyance but could have biological implications.[1] The study suggested that the static electricity generated by polyester could interfere with the normal function of the testicles, further hindering sperm production and quality. These findings offer a compelling look into how a seemingly innocuous choice of fabric could have unintended physiological consequences.

Polyester's Effect on Men's Fertility

The impact of polyester underwear on male fertility deserves a closer examination. The core issue lies in the fact that elevated scrotal temperatures can be detrimental to sperm production. The human testicles are external to the body precisely to maintain a temperature conducive to sperm production, which is typically a few degrees cooler than the body's core temperature.[2] Polyester, being less breathable than natural fabrics, traps heat close to the body, leading to an increase in scrotal temperature. This rise in temperature can lead to a condition known as "heat stress" on the testes, resulting in a significant reduction in sperm count and motility, as well as potential damage to sperm DNA.[2]

Supporting studies have corroborated these findings, indicating a clear link between the type of underwear worn and sperm health. Men who primarily wore tighter, synthetic underwear were found to have lower sperm counts compared to those who opted for looser, natural-fabric underwear.[3] This correlation underscores the importance of fabric choice in underwear for maintaining optimal testicular health and fertility.

The implications of these studies are far-reaching. For couples trying to conceive, or for men concerned about their reproductive health, reevaluating the choice of underwear fabric could be a simple yet effective step. The growing body of research in this area serves as a caution, prompting a reexamination of how everyday lifestyle choices, down to the type of underwear worn, can have a profound impact on health and wellbeing.

The Impact on Women's Fertility

While much of the focus has been on polyester's effects on male fertility, emerging research suggests that women may also be affected. Studies indicate that wearing polyester underwear could potentially inhibit the production of progesterone, a key hormone in women's reproductive health.[4] Progesterone plays a crucial role in regulating the menstrual cycle and is essential for maintaining a healthy pregnancy. A disruption in progesterone levels can lead to various reproductive issues, including irregular menstrual cycles and difficulties in conceiving.

The mechanism behind this effect is more complex than the temperature-related issues seen in men. However, the potential for synthetic materials like polyester to disrupt hormonal balance is a growing area of concern. Researchers are exploring how synthetic fibers might interact with the body's natural processes, possibly leading to hormonal imbalances. While this field of study is still in its early stages, the preliminary findings add to the growing body of evidence that the choice of underwear material can have significant health implications.

Alternatives to Polyester Underwear

Given the concerns raised about polyester's impact on fertility, it's important to consider alternative materials for underwear. Natural fabrics offer several advantages over synthetic ones like polyester, particularly in terms of breathability and overall impact on reproductive health.

  • Organic Cotton: Organic cotton is a popular choice for underwear due to its softness, breathability, and hypoallergenic properties. Unlike conventional cotton, organic cotton is grown without the use of harmful pesticides or synthetic fertilizers, making it a more eco-friendly and health-conscious option.
  • Linen: Linen, made from the fibers of the flax plant, is another excellent choice. It's highly breathable, lightweight, and has natural moisture-wicking properties, making it ideal for maintaining a healthy and comfortable temperature.
  • Silk: Silk is known for its luxurious feel and natural temperature-regulating properties. It's exceptionally soft and can be a good option for those with sensitive skin. However, it requires more delicate care than other fabrics.
  • Hemp: Hemp underwear is gaining popularity due to its durability, breathability, and environmental benefits. Hemp fabric is made from the fibers of the cannabis sativa plant and is often grown with minimal chemical inputs.

When choosing natural fabric underwear, it's essential to consider the fit as well. Loose-fitting underwear can further aid in maintaining an optimal temperature and ensuring proper airflow, which is beneficial for both men's and women's reproductive health.

Switching to underwear made from natural materials can be a simple yet effective way to potentially improve fertility and overall well-being. As awareness grows about the potential drawbacks of synthetic fabrics like polyester, more people are turning to these natural alternatives for their comfort, health benefits, and environmental sustainability.

The implications of this research are especially significant given the widespread use of polyester in women's underwear. Women considering pregnancy or experiencing fertility issues might benefit from being aware of these findings. As research continues to unfold, it could lead to a broader reevaluation of the materials used in women's clothing, especially items worn close to the body, like underwear. The potential impact of polyester on women's fertility adds another dimension to the conversation about reproductive health and the everyday choices that influence it.


The emerging research highlighting the impact of polyester underwear on fertility underscores the importance of fabric choice in our daily wear. Men and women alike can face significant reproductive health challenges due to the heat-trapping and potential hormonal-disrupting properties of synthetic materials. Switching to natural fabrics like organic cotton, linen, silk, and hemp offers a practical solution. These materials not only provide comfort and breathability but also potentially contribute to better reproductive health outcomes. Therefore, reevaluating our choices in something as commonplace as underwear becomes not just a matter of personal preference, but a health-conscious decision, vital for our overall well-being and fertility.

  1. Shafik, A. “Contraceptive efficacy of polyester-induced azoospermia in normal men.” Contraception vol. 45,5 (1992): 439-51. doi:10.1016/0010-7824(92)90157-o
  2. Ivell, Richard. “Lifestyle impact and the biology of the human scrotum.” Reproductive biology and endocrinology : RB&E vol. 5 15. 20 Apr. 2007, doi:10.1186/1477-7827-5-15
  3. Mínguez-Alarcón, Lidia et al. “Type of underwear worn and markers of testicular function among men attending a fertility center.” Human reproduction (Oxford, England) vol. 33,9 (2018): 1749-1756. doi:10.1093/humrep/dey259
  4. Shafik, A. “Effect of different types of textiles on pregnancy.” Clinical and experimental obstetrics & gynecology vol. 34,4 (2007): 244-6.

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