That drawer full of underwear might be harboring something you never considered. Most people grab whatever’s on sale or looks cute without thinking twice about what it’s made from. But doctors and toxicologists are raising red flags about synthetic fabrics commonly used in underwear manufacturing. These materials contain plastics and chemicals that can affect your body in ways you probably didn’t expect. The underwear industry has shifted dramatically from natural fibers to synthetic materials over the past few decades, and your health might be paying the price. Understanding what’s actually touching your skin all day matters more than you think.
Synthetic fabrics are the main culprit doctors warn against
Walk into any store and you’ll find underwear made from polyester, spandex, nylon, and elastane dominating the shelves. These synthetic materials are essentially plastics that manufacturers use because they’re cheap to produce and offer stretch and durability. The problem is that these fabrics contain chemicals used in their production that remain in the finished product. Unlike cotton or other natural fibers, synthetics are created through chemical processes involving countless toxic substances. These materials might feel soft and stretchy, but they’re fundamentally different from what humans wore for centuries before the modern textile industry took over.
What makes synthetic underwear particularly concerning is how closely it sits against your skin for extended periods. Dr. Li Li, an environmental chemist, explains that chemicals can slowly leach from the fabric through natural diffusion or friction when the material rubs against skin. When you sweat, the moisture and natural oils on your skin actually help dissolve these chemicals, increasing absorption. Your body temperature also plays a role in releasing chemicals from synthetic fabrics. The combination of warmth, moisture, and constant contact creates an environment where chemical transfer happens more readily than with other clothing items you wear.
PFAS chemicals coat many underwear products
Beyond the synthetic fibers themselves, manufacturers often apply additional chemical coatings to underwear during the finishing process. Per- and polyfluoroalkyl substances, commonly called PFAS or “forever chemicals,” are frequently used to make fabrics water-resistant, oil-resistant, or stain-resistant. These chemicals earned their nickname because they’re incredibly stable and don’t break down in natural conditions. They accumulate in your body and in the environment over time. Melamine is another common coating chemical that manufacturers use to achieve certain fabric properties. Even underwear made from natural cotton can have these chemical finishes applied, though the base material itself is safer than synthetics.
The concerning part about PFAS exposure is the potential long-term effects. These chemicals have been linked to negative effects on the liver, kidneys, and nervous system according to research. While wearing underwear with PFAS isn’t automatically dangerous, the cumulative exposure from multiple sources throughout your day adds up. You’re already exposed to these chemicals through water bottles, food storage containers, non-stick cookware, and various other products. Your underwear represents another daily exposure source that you can actually control by making better choices about what you buy and wear regularly.
Skin irritation is the most common immediate problem
You might have experienced unexplained itching, burning, or discomfort in your genital area without knowing the cause. Synthetic underwear fabrics are often the hidden culprit behind these annoying symptoms. The chemicals in synthetic materials can trigger allergic reactions or irritate sensitive skin, especially in the warm, moist environment created by underwear. Contact dermatitis and eczema are common conditions that flare up when synthetic fabrics and their chemical treatments come into contact with delicate skin. Many people assume they have a yeast infection when the real problem is simply the underwear they’re wearing every day.
The genital area has particularly sensitive skin that’s more vulnerable to irritation than other parts of your body. Synthetic fabrics also trap heat and moisture rather than allowing air circulation. This creates an environment where bacteria and yeast thrive, potentially leading to infections beyond just irritation. Dr. Erica Newlin, an OB/GYN, points out that wrong underwear choices can contribute to bacterial vaginosis, vulvar itching, irritation, burning, pain, and yeast infections. If you’ve been dealing with recurring problems in these areas, your underwear fabric might be a major contributing factor that’s easy to overlook.
Washing doesn’t remove the chemicals from synthetic underwear
You might think throwing your underwear in the wash removes whatever chemicals are present, but that’s not how it works. Most garments go through multiple washes during the manufacturing process before they ever reach store shelves. These industrial washings don’t significantly reduce the chemical content in synthetic fabrics. Toxicologist Shannon Fitzgerald notes that although many harmful chemicals are rinsed out during production, residual concentrations remain and continue to be released during regular use. The chemicals are integrated into the fabric structure itself, not just sitting on the surface where water can wash them away.
In fact, your laundry routine might actually make things worse. Many conventional detergents leave chemical residues on clothing that can cause additional vulvar irritation and itching. Fabric softeners are particularly problematic because they coat fibers with silicones, oils, and other substances that reduce breathability and add more chemicals next to your skin. Dryer sheets create similar problems. If you’re experiencing irritation, switching to hypoallergenic, fragrance-free, and dye-free detergents can help. Some people find it beneficial to run underwear through an extra rinse cycle. But these steps only address detergent residue, not the chemicals inherent in synthetic fabric materials themselves.
Cotton underwear is the safest option available
Medical professionals consistently recommend 100% cotton underwear as the best choice for daily wear. Cotton is a natural fiber that breathes, allowing air circulation to keep the genital area dry. It wicks away excess sweat and moisture that bacteria and yeast need to grow. Unlike synthetic fabrics, cotton is far less likely to cause allergic reactions, making it ideal for people with sensitive skin. Pure cotton doesn’t contain the plastic-based chemicals found in polyester, spandex, or nylon. While cotton underwear might still have some dyes or minor finishing treatments, you’re exposing yourself to significantly fewer chemicals compared to synthetic options.
The challenge is finding underwear that’s actually 100% cotton. Many brands feel like cotton but contain synthetic fiber blends when you check the label. Some underwear has a small cotton crotch panel surrounded by synthetic fabric, but this doesn’t provide the same protection or breathability as all-cotton construction. For the best results, look for organic cotton options when possible. Organic cotton is grown without synthetic pesticides and often processed with fewer chemicals than conventional cotton. Plain white cotton is ideal if you want to avoid dyes completely. Brands like Quince, Jockey, Pact, Organic Signatures, and Nads offer underwear options that are 100% cotton or contain only minimal synthetic content.
Reading labels carefully prevents accidental synthetic purchases
Shopping for underwear requires more attention than you might expect. Packaging often emphasizes comfort or style without clearly stating fabric content. You need to physically check the label sewn into the garment or printed on the tag to see what materials are actually used. Look for “100% cotton” specifically, rather than assuming a product is cotton-based on how it looks or feels. Some underwear marketed as cotton contains 70% or 80% cotton mixed with polyester or spandex. Even small percentages of synthetic fibers introduce the chemical concerns that doctors warn about.
Be aware that terms like “cotton blend” or “cotton feel” are marketing language that indicates synthetic content. If an elastic waistband or leg openings contain spandex, that’s a small amount that most experts consider acceptable as long as the main body fabric is 100% cotton. However, synthetic elastic still introduces some chemical exposure. The safest approach is finding underwear with as close to 100% natural fiber content as possible. When shopping online, fabric composition should be listed in the product details. Don’t hesitate to contact customer service if this information isn’t clearly stated. Investing a bit more money in quality cotton underwear is worthwhile, given how many hours per day you wear it.
Special occasions don’t require compromising your health
You might worry that cotton underwear isn’t available in attractive styles for special occasions. While lacy synthetic underwear is common, you don’t have to choose between looking good and protecting your health. Non-cotton underwear is fine to wear occasionally if you don’t have sensitivity issues. The keyword is occasionally. Wearing synthetic underwear for a date night or special event once in a while won’t cause the same problems as daily synthetic underwear use. However, if you’re prone to yeast infections, bacterial vaginosis, or vulvar irritation, even occasional synthetic underwear might trigger problems.
More brands are recognizing consumer demand for natural fiber options in various styles beyond basic briefs. You can find cotton underwear in bikini cuts, boy shorts, hipsters, and other popular styles. Some companies specialize in organic cotton intimate apparel that doesn’t sacrifice style for health considerations. Thongs are a special case. Research shows they don’t necessarily increase infection risk for most people. But if you have recurrent vaginal or vulvar problems, medical professionals recommend choosing looser, more breathable styles in cotton fabric. Ultimately, your underwear drawer can contain a mix of everyday cotton basics and occasional special styles, as long as your regular daily underwear is made from natural fibers.
Persistent symptoms require professional medical attention
Switching to cotton underwear should help if synthetic fabrics are causing irritation or contributing to infections. However, if you continue experiencing vulvar burning, itching, pain, or recurring infections after making the switch, something else is going on. Many conditions can cause these symptoms, and they require different treatments. Don’t assume you have a yeast infection without getting it checked. Medical professionals often find other causes like contact dermatitis, eczema, bacterial vaginosis, or other conditions when patients come in complaining of itching they assumed was yeast-related.
A healthcare provider can properly diagnose what’s causing your symptoms and recommend appropriate treatment. Sometimes the solution is as simple as changing underwear fabric, switching detergents, or adjusting other hygiene practices. Other times, you might need medication or other interventions. Don’t let discomfort disrupt your life when help is available. Be prepared to discuss your underwear choices, laundry products, and hygiene habits with your doctor, as these factors often play a role in genital area problems. Once you know the specific cause of your symptoms, you can take targeted action to find relief rather than guessing what might help.
Your underwear choices matter more than most people realize. Synthetic fabrics containing plastics and chemical coatings can cause immediate irritation and potentially contribute to longer-term concerns. Cotton underwear, preferably 100% organic cotton, provides the safest option for daily wear. Reading labels carefully ensures you’re actually getting natural fibers rather than synthetic blends. Simple changes in what touches your skin all day can make a real difference in your comfort and well-being.
