ONSEN LABO · SLEEP-TECH PROTOCOL · v1 · EST. 2026 · TOKYO
Sleep,
prescribed.
Japanese onsen minerals, AI-matched to your sleep profile.
An evening ritual. Backed by sleep science.
WHY NOW
The bath is the next sleep device.
Wearables made sleep measurable. Pharmacology is racing to make it prescriptive. Onsen Labo is building the third lane — a non-pharma, mineral-based protocol with reproducible thermoregulation data behind it, delivered as a ritual you already know how to perform.
The cultural moment for hot-water immersion as a sleep input has arrived — well ahead of the supply chain built to serve it from real onsens.
- $5.2B+Sleep-tech categoryRecent valuations · 2024
- 1.2B+#magnesium viewsTikTok cumulative
- 36.8MInbound to Japan2024 — record year
- #1Heat-exposure protocolsTop wellness research, 2026
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 Labo'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/LNOBORIBETSU · HAKONE — sourcing partnerships in final confirmation. Full five-onsen lineup announced at launch.NOT A BATH BOMB
The end of the bath bomb era.
The legacy bath category was built around scent, color, and retail-shelf appeal. The new category is built around measurable inputs to sleep.
- STEP 01 / 03
Answer 12 questions.
About your sleep, your skin, your evening.
Twelve questions translate your sleep, physiology, and seasonal context into a measurable profile.
~ 90 SECONDS - STEP 02 / 03
AI matches your profile.
To one of 47 onsen mineral profiles.
Thousands of onsen mineral compositions are cross-referenced against your neural and metabolic signature.
~ 5 SECONDS - STEP 03 / 03
Receive your bath formula.
And your nightly ritual begins.
A formulation engraved with your name arrives — a single, unrepeatable onsen protocol.
Q3 2026 SHIPMENT
PRICING · PRE-LAUNCH
Two tiers. One protocol.
$89/ month
14 bath sachets · Handwritten Founder Letter, curated by Mitsuki.
Limited to the first cohort$55/ month
8–10 AI-personalized bath sachets · Prescription Card.
Launches Q3 2026No commitment · Cancel anytime before your next shipment
- INSPIRED BYKusatsu · Beppu · Gero · Noboribetsu · Hakone
- CURATED INTokyo, Japan
- SHIPS FROMTokyo → Worldwide
- BETA1,000+ rituals · 12 countries
Things you may reasonably ask before submersion.
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12,847 RESERVATIONS · LAUNCHING Q3 2026 · NO SPAM. ONE EMAIL AT LAUNCH.
THE 90-MINUTE RITUAL
A prescription. And a nightly ceremony.
Forty minutes in the water. Fifty more under cooling sheets. The Japanese bath has been used this way for thirteen centuries — closer to tea ceremony than to soak. We have kept the form. The minerals are matched to you; the rhythm is the one your evening already knows.
