4.7 Loved by 35,000+ Guys

Ridiculously Soft. Incredibly Durable. Naturally Sustainable.

The secret to UnderFit’s superior comfort starts with the fabric. We use a luxurious, sustainably sourced TENCEL™ fabric blend. It feels great against your skin, provides all-day comfort and is built to last.

Why Beats Cotton (Hands Down)

Our products are made from the perfect combination of Lenzing TENCEL™ Modal and Lyocell, two incredibly resilient semi-synthetic fibers knit together to create undershirts that are breathable, move with you all day, and retain their shape for years to come. You’ll never want to go back to cotton.

Modal

  • Ultra‑soft with a silky feel
  • Retains softness after washing
  • Excellent moisture control
  • Eco‑friendly with lower water and carbon use

Lyocell

  • Smooth with a subtle
  • High strength and durability
  • Excellent wicking and breathability
  • Closed‑loop production with high solvent recovery
plants

Better for You. Better for the Planet.

  • From Nature

    Our fibers come from sustainably farmed Beechwood and Eucalyptus trees grown in Europe — never from old-growth forests.

  • Closed-Loop Production

    TENCEL™ is made in a revolutionary solvent-spinning process that recycles water and reuses 99% of its solvent. That means less waste, lower impact, and maximum efficiency.

  • Biodegradable & Compostable

    In the unlikely event your UnderFit ever hits a landfill, it will break down naturally — without leaving harmful chemical residue.

  • Certified & Ethical

    Lenzing Modal® and TENCEL™ have earned United States Department of Agriculture (USDA) BioPreferred® designation.

  • Ethical Manufacturing

    Our factory partner in Vietnam is FairLabor and WRAP Gold Certified, assuring safe, legal and ethical manufacturing processes.

  • Comfort You Can Feel Good About

    When you choose UnderFit, you’re not just upgrading your comfort — you’re making a choice that supports ethical manufacturing, reduces waste, and respects the planet.