By XLoveLab Health Team
Think your underwear is safe? The fabric you're wearing might be secretly causing health problems. Here's what medical experts say.
1. Polyester
According to NBC Select, "one of the most common risks is skin irritation" from synthetic fabrics like polyester (NBC Select). Polyester traps heat and moisture, creating a breeding ground for bacteria.
2. Nylon
Healthline warns that "synthetic materials like nylon and spandex don't allow the area to breathe. Instead, they trap heat and moisture" ("8 Underwear Tips"). This creates an ideal environment for yeast infections.
3. Spandex/Elastane
ThirdLove explains that "synthetic-made materials like nylon and spandex" can cause "bacterial growth and yeast infections" ("Best and Worst Types").
4. Synthetic Lace
The New York Post reports that "synthetic lace underwear" is among the worst offenders for vaginal health, especially when worn daily (Ross).
5. Rayon
Kiseau explains that many brands advertise "organic cotton," but if only the gusset is cotton and the rest is a synthetic blend, you're still at risk ("What Fabrics Are Bad").
What to Choose Instead
| Fabric | Breathability | Moisture-Wicking | Recommendation |
|---|---|---|---|
| 100% Cotton | ★★★★★ | ★★★★☆ | Best choice |
| Bamboo | ★★★★★ | ★★★★★ | Great alternative |
| Modal | ★★★★☆ | ★★★★★ | Good for sensitive skin |
| Merino Wool | ★★★★★ | ★★★★★ | Gynecologist-approved |
References
Healthline. "8 Underwear Tips for Vaginal Health." Healthline, Healthline Media, 2024, healthline.com/health/womens-health/underwear-hygiene.
NBC Select. "Is There Plastic in Your Underwear?" NBC News, 2024, nbcnews.com/select/shopping/plastic-in-underwear-rcna241678.
Ross, MD. "The Best and Worst Underwear for Your Vaginal Health." New York Post, 16 June 2025, nypost.com/2025/06/16/health/the-best-and-worst-underwear-for-your-vaginal-health/.
ThirdLove. "The Best and Worst Types of Underwear For Your Health." ThirdLove Blog, thirdlove.com/blogs/learn/the-best-and-worst-types-of-underwear-for-your-health.