Pick the size you usually wear in underwear. Our boxers have a snug, second-skin fit.

• Between two sizes? Size up for a relaxed feel, down for a firmer hold.
• Check the size chart above for body measurements.

Wrong size? Exchanges are free. Just email us.

• Machine wash cold, gentle cycle.
• Use a wash bag to protect the fabric.
• No bleach, no fabric softener.
• Hang dry or tumble dry low.

Treat them right and they'll keep their shape and softness wash after wash.

No bots. No auto-replies. A real person from our team answers every message.

Sizing, shipping, returns, or just a question before you order: reach out.

Message us: our contact page
Phone: +1 215 666 0549 (Mon–Fri, 8 AM – 5 PM US Eastern)

We usually reply within 24 hours.

We're confident you'll love them. If they don't feel right, no stress.

You have 45 days to get your money back.

1. Message us through our contact page with your order number.
2. We send you the return instructions.
3. Once your return arrives, we process your refund.

Full conditions in our refund policy.

We started Underline because we were tired of underwear that rides up, traps heat and loses its shape after a few washes.

So we built the boxer we wanted to wear: soft bamboo, real airflow, a waistband that stays put. No gimmicks, just everyday comfort done right.

Thanks for being here.

- The Underline Team