Products
MUJI — Men's Smooth Front Open Boxer Brief

MUJI

Men's Smooth Front Open Boxer Brief

UnderwearSKU: 4550512582403
B

Strong across the board — well-made, safe to wear, and low planet cost.

Daily wear, no caveats.

Quality B · 79Health A · 98Eco · 82

Why this grade?

This product scored 79/100 based on its composition of Lyocell 95%, Spandex 5%. Blended from 95% Lyocell, 5% Spandex — the overall score is a weighted average based on each material's proportion.

B (70-84): Good quality — above average across most metrics.

Composition

Lyocell 95%, Spandex 5%

Good quality, eco-friendly

Solid fabric with strong environmental credentials. Lyocell (95%) is doing the heavy lifting. This is a smart buy.

🌍

This fabric will take 200+ years to decompose. That means a shirt you buy today will still exist in the year 2226.

🧺

Dryer heat destroys spandex/elastane over time. Your leggings and stretchy clothes will last 2x longer if you skip the dryer.

⚖️

Lyocell (score 80) is carrying this blend. Spandex (score 55) is pulling it down.

Eco Rating

82/100

Strong environmental credentials

Learn about eco ratings →

Biodegradability

Not Biodegradable

Materials will persist in the environment for decades.

Health & environmental impact →

Health Impact

Microplastic shedding · skin-contact synthetic load · likely chemical treatments

A98/100

Low health impact — predominantly natural fibers with no major treatment flags.

MicroplasticsLOW

Very low

Skin contactLOW

5% synthetic

ChemicalsLOW

No flags

Care Guide

Washcold (30°C)
Cycledelicate
Detergentmild
BleachDo not bleach
Dryline dry
Ironlow
Dry Cleanavoid
SoftenerNo

Best For

🏃Athletic Wear
Good

Good breathability (79) and moisture wicking (67) for light activity

👕Everyday Casual
Good

Good comfort (87) and care ease (62) for casual wear

👔Formal/Office
Good

Good durability (65) and comfort (87) for office wear

😴Sleepwear
Good

Good comfort (87) and breathability (79) for sleeping

🩲Underwear
Good

Good breathability (79) and comfort (87) for undergarments

🌧️Rain/Weather
Good

Good moisture wicking (67) and durability (65) for weather protection

⛰️Outdoor/Hiking
Good

Good durability (65) and breathability (79) for outdoor activities

🌱Sustainable Fashion
Good

Good sustainability score (82)