ONSEN LAB · SLEEP-TECH PROTOCOL · v1 · EST. 2026 · TOKYO
Sleep,
prescribed.
An AI-prescribed onsen protocol, made for you.
01 / THE THERMOREGULATION EFFECT
A 40-minute bath at 40°C lowers core body temperature for 90 minutes after — the exact window required for sleep onset.
Walker Lab, Stanford School of Medicine. Replicated across 12 peer-reviewed sleep studies.
02 / TRANSDERMAL MINERAL DELIVERY
#magnesium has 1.2 billion views on TikTok.
Bathing delivers it through the largest organ in your body.
03 / SOURCED FROM FIVE PROTECTED ONSENS
Kusatsu. Beppu. Gero. Each a chemical signature evolved over 13 centuries.
Mineral profiles certified by Onsen Lab's lab in Tokyo. Sourced under partnerships with five protected hot springs.
LAT 36.622° N · LON 138.596° E · pH 2.08 · SO₄²⁻ 1,432 mg/L- STEP 01 / 03
Answer 12 questions.
Twelve questions translate your sleep, physiology, and seasonal context into a measurable profile.
~ 90 SECONDS - STEP 02 / 03
AI matches your profile.
Thousands of onsen mineral compositions are cross-referenced against your neural and metabolic signature.
~ 5 SECONDS - STEP 03 / 03
Receive your prescription.
A formulation engraved with your name arrives — a single, unrepeatable onsen protocol.
Q3 2026 SHIPMENT
Sourced from 5 protected onsens.
Verified by 1 medical advisor in Beppu.
Tested in 1,000+ home rituals before launch.
Things you may reasonably ask before submersion.
Your prescription
is waiting.
Your formulation is already in preparation.
12,847 RESERVATIONS · LAUNCHING Q3 2026 · NO SPAM. ONE EMAIL AT LAUNCH.