The Everyday Thong
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The Everyday Thong - Black
your underwear deserves better
You care about your skin, your wellness, your rituals. We’re pioneering care for your most intimate parts.
Powered by UNDERskin™
Prebiotics and probiotics, infused into the fabric, transferring to your skin all day. Supports your microbiome. Strengthens your skin barrier. Promotes a healthier appearance. 100% biobased. Developed in Switzerland.
Twice the softness of cotton
Our underwear is made from TENCEL™ Modal—sustainably derived from trees and twice as soft as cotton. Gentle on the skin and made to feel like nothing at all.
Let your ____ breathe freely
TENCEL™ fibers are unfavorable for bacteria growth. They wick away moisture and keep you fresh through the day. Designed to help reduce the risk of unwanted infections.
OEKO-TEX Certified
OEKO-TEX® certified —clean, non-toxic with no harmful substances
set apart by design
TENCEL™ modal antimicrobial fabric derived from trees
Prebiotics + probiotics infused in the fabric for a healthier skin microbiome
Tested by real women, with over 1,000 five-star reviews
Engineered for optimal airflow and breathability
A 2cm extra-long gusset for everyday protection
Soft leg elastics designed to eliminate digging in
frequently asked questions
The Everyday Thong is made from ultra-soft modal for daily comfort — ideal under work clothes, jeans, and dresses. The Workout Thong uses a moisture-wicking performance fabric that handles sweat and movement during exercise. Same flattering thong shape, different fabric engineered for different purposes.
Yes. The Everyday Thong is Underdays’ best option for completely invisible underwear under any outfit, including white, thin, or body-hugging fabrics.
Yes — that’s exactly what it’s designed for. The modal fabric is softer than cotton and the wider waistband sits flat without cutting in. Many of our customers wear the Everyday Thong as their daily go-to, not just for special occasions or specific outfits.
Our Everyday Collection is treated with HeiQ Skin Care™ — Swiss synbiotic technology that supports your skin's microbiome through fabric-to-skin contact. Underwear that works like skincare. It's a cosmetic treatment that promotes promotes healthy skin appearance, not a medical product, it doesn't diagnose, treat, or prevent disease.
No, it's already built in. HeiQ Skin Care™ is embedded directly into the fabric during production, so it's working from the very first wear. No creams, sprays, or steps required.
No change to handfeel, breathability, colour, or fit, it feels exactly like the Everyday you already love. Non-irritant, human skin patch tested, and all ingredients INCI-listed.
For light activities like walking, gentle yoga, or Pilates, the Everyday Thong works well. For anything higher intensity — running, HIIT, hot yoga, weight training — the Workout Thong’s moisture-wicking fabric will keep you drier and more comfortable.
We’re focused on making the best underwear possible. Bralettes are currently in development— sign up to our mailing list to be the first to know when they launch.
Our core colours such as Black and Sand are always available and restocked regularly. Fashion colours and seasonal drops are limited edition — once they sell out, they won't be coming back. If you spot a colour you love, we'd recommend grabbing it before it's gone. Follow us on social or sign up to our mailing list to be the first to know when new color drops land.
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