Frequently Asked Questions
PRODUCT
How does period underwear work?
UNDERDAY combines a soft top layer, an absorbent core and a protective barrier layer built into the underwear itself, so it looks and feels like everyday underwear while helping manage period flow.
Can I wear UNDERDAY by itself?
Yes — UNDERDAY is designed to be worn on its own. Choose the protection level (LIGHT, REGULAR, HEAVY or NIGHT) that matches your flow.
How do I choose my protection level?
Match the level to your day: LIGHT for spotting or light days, REGULAR for typical flow, HEAVY for heavier days, and NIGHT for overnight wear. See our How It Works page for more detail.
Can I wear it overnight?
Our NIGHT style is designed specifically for overnight wear. [MERCHANT TO PROVIDE] any additional overnight guidance.
FIT
How do I choose my size?
See our Size Guide for measurements by size.
Should period underwear fit tightly?
UNDERDAY is designed to fit like everyday underwear — snug but comfortable, not compressive. If you're between sizes, see the guidance on our Size Guide page.
CARE
How do I wash UNDERDAY?
Rinse, then machine wash and air dry. See our Care Guide for the full process.
Can it go in the dryer?
We recommend air drying only. [REQUIRES PRODUCT TEST DATA / CARE LABEL SPECIFICATIONS] for exact care instructions.
ORDERS
Where do you ship?
[MERCHANT TO PROVIDE] current shipping destinations. See our Shipping Policy for details.
How long does shipping take?
[MERCHANT TO PROVIDE] shipping timelines. See our Shipping Policy for details.
RETURNS
Can underwear be returned?
See our Refund Policy for current eligibility and timelines.
What happens if I receive the wrong size?
Contact us at hello@underday.com or visit our Contact page and we'll help sort it out.