The Short Answer
We recommend an avoid verdict for silver in period underwear. Many popular brands add silver as an antimicrobial to block odors. However, the FDA warns that silver can kill the beneficial Lactobacillus bacteria that keep your vagina healthy.
Disrupting this microbiome increases your risk of bacterial vaginosis (BV) and yeast infections. A **2023 study by UK watchdog Which? found potentially harmful levels of silver in several major brandsāwith some testing as high as 126.7 mg/kg**.
Why This Matters
The skin around the vulva is exceptionally thin and highly absorbent. Whatever chemicals are in your period underwear can easily migrate into your body during the long hours of wear, putting your sensitive tissue at risk. Is Period Underwear Safe
Your vaginal microbiome relies on a delicate balance of bacteria to fight off infections. Silver doesn't distinguish between good and bad bacteriaāit wipes them all out, significantly increasing your risk of vaginal irritation.
Washing silver-treated underwear is also an environmental hazard. Silver is highly toxic to aquatic life, and every trip through the washing machine sends these heavy metals straight into our waterways.
What's Actually In Period Underwear
- Silver Nanoparticles (Nanosilver) ā Ultrafine silver particles used to kill odor-causing bacteria. These are small enough to potentially penetrate the skin barrier and disrupt the microbiome.
- Silver Zeolite / Silver Chloride ā Other forms of silver biocides. They slowly release silver ions over time to maintain freshness, meaning continuous chemical exposure for your body.
- PFAS ā "Forever chemicals" historically used for waterproofing in period underwear. Many brands that used silver also faced lawsuits over PFAS contamination. Is There Pfas In Period Underwear
What to Look For
Green Flags:
- "Biocide-Free" labels ā The only way to guarantee a brand isn't using chemical antimicrobials in their gusset.
- Natural odor control ā Brands that rely on highly breathable, moisture-wicking fabrics like organic cotton, bamboo, or Tencel instead of chemical treatments.
- Oeko-Tex Standard 100 ā While it doesn't strictly limit silver, it ensures the product is tested for heavy metals and other harmful substances. Safest Period Underwear
Red Flags:
- "Anti-odor" or "Antimicrobial" claims ā These are almost always code words for silver treatments, Agion, or other chemical biocides.
- Silver, Nanosilver, or Agion in the materials list ā If you see these ingredients listed on the tag or website, leave it on the shelf.
- Lack of transparency ā If a brand won't disclose how they achieve their "odor-blocking" magic, it's highly likely they are using a biocide.
The Best Options
Biocide-free period underwear is the only way to protect your microbiome. Here are the brands getting it right, and the ones to avoid.
| Brand | Product | Verdict | Why |
|---|---|---|---|
| Hello Period | Hello Undies | ā | Independently tested to be free of silver, biocides, and PFAS. |
| Gotyu | Period Underwear | ā | Strictly biocide-free and uses natural fabrics for breathability. |
| Modibodi | Period Pants | ā ļø | A 2023 study found very low trace levels (<1mg/kg) of silver. |
| Intima by Bodyform | Period Pants | š« | Tested at a massive 126.7 mg/kg of silver in consumer testing. |
| Thinx | Period Underwear | š« | Tested positive for silver (8.3 mg/kg) and has a history of PFAS. Is Thinx Safe |
The Bottom Line
1. Ditch the "anti-odor" marketing. If period underwear claims to magically eliminate smells, it is almost certainly using silver or other chemical biocides.
2. Protect your microbiome. Your vagina is self-cleaning and relies on good bacteria; silver threatens that balance and invites yeast infections.
3. Go biocide-free. Look for brands that explicitly state they do not use silver, biocides, or PFAS in their gussets. Period Underwear No Pfas
FAQ
Does all period underwear have silver?
No, but many popular mainstream brands do. Silver treatments are incredibly common in the industry to market products as "odor-free," but a growing number of clean brands are shifting to completely biocide-free designs.
Can silver in underwear cause yeast infections?
Yes, it can significantly increase your risk. Silver kills the healthy Lactobacillus bacteria that keep yeast in check, making you much more susceptible to yeast infections and bacterial vaginosis (BV).
What is Agion?
Agion is a commercial antimicrobial technology that uses silver and copper. Many activewear and period underwear brands use it to fight odors, but because it relies on releasing silver ions, it carries the exact same microbiome-disrupting risks as other silver treatments.