Better Comfort Protection for your Crown Jewels

100% plastic-free underwear. Hand-crafted from organic Royal Alpaca for the ultimate comfort.

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Nature's Best Underwear.

Hand-crafted from Royal Alpaca—a rare fiber that naturally stays dry, cool, and odor-free from dawn to dusk.

18μ Royal Fiber

18μ Royal Fiber

15% Royal Alpaca for luxury softness, 85% Tencel™ for breathable moisture control. Two natural fibers, one perfect blend.

Biological Cooling

Biological Cooling

Tencel™'s cellulose structure wicks moisture instantly while Royal Alpaca's hollow-core fibers regulate temperature naturally.

The Sanctuary Pouch™

The Sanctuary Pouch™

Every fiber is plant or animal-based. Zero synthetics, zero plastic, zero microplastics shed into your body or the environment.

Hand-Crafted in Peru

Hand-Crafted in Peru

Small batch production in a GOTS-certified Peruvian mill. Sustainably sourced, ethically crafted.

SMALL BATCH PRODUCTION MADE IN PERU

The Royal Boxer Brief

$54.00

Experience the world's only 100% plastic-free underwear. Hand-crafted from organic Royal Alpaca for the ultimate comfort and biological protection.

Select Color: Obsidian
Select Size
Select Bundle
Free shipping over $150
90-Day Fit Guarantee

Estimated delivery March 25 and March 27

The Royal Brief is engineered where it matters most — using the world’s most sophisticated natural fiber.

Born on the Peruvian Altiplano at 4,000 meters above sea level, Royal Alpaca evolved over thousands of years to adapt to extreme temperature swings. Its hollow-core fibers naturally regulate heat, manage moisture, and stay soft against skin. We apply this evolutionary advantage where comfort matters most, then balance it with breathable organic cotton, TENCEL™ Lyocell, and a fabric-encased waistband for all-day support.

Sourced and crafted entirely in Peru, The Royal Brief is designed for men who expect more from what they wear every day — without plastic, gimmicks, or shortcuts.

On skin: Royal Alpaca–powered comfort where it matters most. The Sanctuary Pouch™ combines ultra-fine alpaca fibers with organic cotton and silk for a surface that stays soft, dry, and irritation-free. The fabric-encased waistband sits comfortably without itching, pinching, or rolling.

On the move: A naturally flexible knit moves with you through long days, travel, and light training — maintaining its shape without relying on plastic stretch fibers. Breathable, supportive, and comfortable from morning to night.

Choosing your size: Designed for a true-to-size fit. If you prefer a slightly more relaxed feel or are between sizes, we recommend sizing up.

Details

  • 5.3" inseam — balanced everyday length
  • Sanctuary Pouch™ — targeted support and thermoregulation
  • Fabric-encased waistband — no exposed elastane against skin
  • No-roll construction — stays flat and comfortable
  • Vertical fly — functional, minimal, no excess bulk
  • Tagless interior — nothing to scratch or distract
  • Made in Peru

Sanctuary Pouch™

Royal Alpaca · 100% Organic Cotton · Silk

The most sensitive area deserves the most advanced natural fibers.

Royal Alpaca provides natural thermoregulation and odor resistance, organic cotton adds structure and durability, and a touch of silk reduces friction for all-day comfort.

Why it matters

  • Naturally temperature-regulating
  • Soft, dry, and irritation-free
  • Hypoallergenic and odor-resistant

Main Body Fabric

Organic Cotton · TENCEL™ Lyocell

A breathable, lightweight knit designed for daily wear. Organic cotton delivers durability and a familiar softness, while TENCEL™ Lyocell improves moisture management and long-term shape retention — without relying on plastic stretch fibers.

Why it matters

  • Breathable and moisture-wicking
  • Soft against skin
  • Durable through repeated washes

Waistband

Fabric-Encased Natural Rubber

A supportive waistband that stays comfortable all day. Natural rubber provides stretch and recovery, fully wrapped in soft fabric so no elastic or synthetics touch your skin.

Why it matters

  • Secure fit without digging
  • No exposed elastane
  • Comfortable for all-day wear

Lining & Trim

Organic Cotton

Soft, durable finishes where it counts — chosen for comfort, breathability, and longevity.

At a Glance

  • No plastic against skin
  • Naturally breathable and thermoregulating
  • Designed for male anatomy
  • Crafted for daily comfort and durability

Dyes: Non-toxic and OEKO-TEX® certified — safe for your skin and everything below the belt.

Care: Cold wash, tumble dry low. Shrinkage is normal — size up for the perfect post-wash fit.

SHIPPING
Please allow 1-2 business days for order processing. The cut off time for expedited order is 12pm EST which means orders after that time will go out the next business day. We will email you when the order is shipped. Please check junk/spam if you do not receive it in your inbox.

If you purchased shipping protection from Alti and have a lost, damaged, missing, or stolen package, email us to file a claim.

US SHIPPING RATES
All US orders are shipped via UPS/USPS and should be received within 3-6 business days after processing. Delivery time do not include Saturdays, Sundays or holidays. Shipping rates are calculated by USPS for all orders up to $150. Orders $150+ are eligible for Free Shipping.

We have a 90-day return policy, which means you have 90 days after receiving your item to request a return.

If you’re not satisfied with the fit of your Alti, we offer a 90-day refund guarantee. Here’s how it works:

Only open and try on one pair if you’ve ordered multiple.
Example: If you order an 8-pack, open and try on just one pair. If the fit isn’t right, Return all 8 pairs for a full refund. Make sure the opened pairs are easily recognized as the open ones. (Processing and handling fees may apply)

*We do NOT provide refunds for single pair orders that have been worn or washed.

Note: All shipping costs, duties/import taxes and any other associated fees such as exchange and transaction fees are non-refundable

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ENGINEERING EXCELLENCE

How It's Built

A simple breakdown of why these are the most comfortable boxers you'll ever wear.

Zone 1: The Sanctuary Pouch™

Royal Alpaca
Primary Goal: Pure Comfort Where It Matters Most
The liner concentrates Royal Alpaca fiber right where it counts — softer than cashmere, naturally temperature-regulating, and moisture-wicking. Paired with Tencel™ for structure and breathability. No synthetics, no plastic.

Zone 2: The Body

15% Royal Alpaca / 85% Tencel™
Primary Goal: Breathability, Softness, and Moisture Control
Tencel™ — made from sustainably harvested wood pulp — provides silky breathability and instant moisture management, while Royal Alpaca adds natural thermoregulation and luxury softness. 100% natural, zero microplastics.

Zone 3: The Soft-Density Waistband

Fabric-Encased Natural Rubber
Primary Goal: Secure Fit Without Synthetic Contact
Most luxury brands fail at the finish line by using exposed polyester or plastic elastics. We encase our natural rubber in soft organic fibers, ensuring only nature touches your skin.
OUR FIBERS

Why It's So Soft.

Two extraordinary natural fibers, each bringing something the other can't. Together, they create the most comfortable underwear you'll ever wear.

Royal Alpaca

Royal Alpaca

The world's rarest natural fiber

Thermoregulating

Hollow-core fibers expand to cool and contract to insulate — adapting to your body in real time.

Odor-Resistant

Naturally antimicrobial structure keeps you fresh for days without chemical treatments.

Softer Than Cashmere

Only the top 1% of alpaca fiber qualifies as Royal grade — silk-like to the touch.

Tencel™

Tencel™

Nature's performance fiber

Moisture-Wicking

Moves moisture 50% more efficiently than cotton. You stay dry, not damp.

Silky Breathability

Ultra-fine cellulose fibers create a smooth, cool-to-the-touch feel against skin.

Sustainably Made

Produced from responsibly harvested wood pulp in a closed-loop process. 100% biodegradable.

100% NATURAL
100% NATURAL
BIODEGRADABLE
BIODEGRADABLE
ZERO PLASTIC
ZERO PLASTIC

Alti vs. The Rest

Alti Cotton Synthetic
Temperature Control Yes No No
Moisture-Wicking Yes No Yes
Odor-Resistant Yes No No
Plastic-Free Yes Yes No
Biodegradable Yes Yes No
Stays Cool in Heat Yes No No
CUSTOMER STORIES

Real comfort, real results.

Rated 4.9/5 by our community

I used to overheat in everything. These are the only pairs that actually keep me cool and dry all day.

JR
James R.
Verified Buyer

100% plastic-free was the main reason I bought them. The comfort is just a massive bonus.

SM
Sarah M.
Verified Buyer

The blend of alpaca and Tencel feels like silk. Genuinely better than any cotton pair I've owned.

MT
Michael T.
Verified Buyer

Frequently Asked Questions

View all FAQs

We blend 15% Royal Alpaca — the rarest grade of alpaca fiber, ultra-fine at under 18 microns — with 85% Tencel™, a silky fiber made from sustainably harvested wood pulp. Together they create underwear that naturally regulates temperature, wicks moisture, and resists odor. Both fibers are 100% natural, plastic-free, and biodegradable.

Machine wash cold on a gentle cycle with similar colors. Lay flat to dry or tumble dry on low. No bleach, no fabric softener — the fiber is naturally soft and odor-resistant, so they stay fresh longer between washes.

We offer a 90-Day Fit Guarantee. If they're not the most comfortable underwear you've ever worn, send them back for a full refund. No questions asked.

They fit true to size. The Royal Alpaca and Tencel™ blend has a natural stretch that conforms to your body without losing shape. If you're between sizes, we recommend going with your usual size — the fabric adapts.

Royal Alpaca fiber is hand-sheared once a year by fourth-generation herders in Peru, sorted by micron count, and processed at a GOTS-certified mill. Small batch production means every pair gets the attention it deserves. The 3-pack and 6-pack bundles bring the per-pair price down significantly.

Yes. Every fiber is natural — 15% Royal Alpaca and 85% Tencel™, both biodegradable. Even our waistband uses fabric-encased natural rubber instead of exposed synthetic elastics. Zero microplastics, zero polyester, zero compromise.

Both Royal Alpaca and Tencel™ are naturally durable fibers. With proper care, expect these to outlast conventional underwear significantly. The blend resists pilling, maintains its shape, and actually gets softer with each wash.