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Your Session History
Track your experiences and rate prediction accuracy
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Know your window

GummyClock is a harm-reduction tool for adults in jurisdictions where cannabis is legal. You must be 21 or older to continue.

GummyClock
Know your window

Finally know when your edible will hit.

Enter your body and your dose.
See exactly when you will peak and when you will come down.

Calculate my window
The Calculator

Your body.
Your dose.
Your window.

Your Profile
Your weight affects how THC distributes through your body
Used to estimate body composition
Metabolism naturally slows with age, affecting peak timing
Affects peak concentration — research shows meaningful difference
A heavy meal delays peak by up to 3.5 hours
Your Tolerance
Rare
First time Occasional Weekly Frequent Daily
Regular use builds tolerance — your peak will be lower and shorter
Peak Alert
Two ways to get pinged when your edible peaks. Pick either or both.
Option A — Text message
Best-effort
Works if your carrier is Verizon, T-Mobile, or AT&T. We send through free carrier email-to-SMS gateways — reliable for most, but not guaranteed. MVNOs and smaller carriers that ride on these networks (Cox Mobile, Mint, Visible, Cricket, etc.) usually work too. International numbers won't.
US 10-digit number. We don't store it anywhere other than your profile.
Send me a peak alert
Best-effort delivery. No promises.
Option B — Add to Home Screen
Reliable
A one-time setup that puts GummyClock on your phone's home screen and unlocks native push notifications — same satisfying ping as any app, no carrier gatekeeping. About 60 seconds of setup, works forever.
Once installed, return here to enable push notifications.
Your Dose
Check your package — standard dose is 5–10mg
Defaults to right now. Edit if you took it earlier.
🔒

Your numbers never leave your browser. We calculate, we do not collect. No account required.

Your Results

Your window

—
Peak time
—
Peak THC (ng/mL)
—
Mostly cleared
THC Concentration Over Time
Purple line — watch this for timing. It tells you when effects start, when you peak, and when you come down.

Dashed line — this is 11-OH-THC, your liver's amplified version of THC. The number looks smaller, but multiply it by 10 to get the true subjective effect. A dashed line reading of 2 ng/mL feels like 20 ng/mL of THC. This is why edibles hit harder and last longer than expected — and why taking a second dose before the first has peaked is how most people have a bad experience.

The purple line tells you when. The dashed line tells you how much.
Trace — barely noticeable
Mild — light relaxation
Moderate — clearly felt
Intense — most people uncomfortable above 5 ng/mL
— — Impaired for driving (5 ng/mL legal threshold)
THC Concentration Over Time
Estimates only — not medical advice. Individual responses vary significantly based on tolerance, product formulation, and metabolism. Do not drive or operate machinery while impaired. For use only where cannabis is legal. How this model works →
The Science

How GummyClock works

GummyClock uses a two-compartment pharmacokinetic model — the same mathematical framework used in clinical pharmacology research to describe how substances move through the body over time.

When you swallow an edible, THC absorbs from your gut at a rate described by an absorption constant (kₐ). It then enters your bloodstream and is eliminated primarily through hepatic (liver) metabolism at an elimination rate (kₑ). The resulting blood concentration curve follows a characteristic rise-and-fall shape.

Your body composition matters because THC is highly lipophilic — it binds to fat tissue. Higher body fat percentage lowers your blood peak but extends your duration. We estimate body fat using the Deurenberg formula calibrated separately for biological males and females.

GummyClock also models 11-OH-THC — the active metabolite produced when your liver processes THC. This metabolite is several times more potent than THC itself and crosses into the brain more readily, which is a primary reason edibles feel stronger than inhaled cannabis at equivalent doses.

Stomach state shifts your absorption rate: an empty stomach produces the fastest onset, while a high-fat meal has been shown in controlled studies to delay peak by up to 3.5× compared to fasted conditions.

Research basis: Vandrey et al. (2017), Ohlsson et al., PMC6922062 (fed vs. fasted THC pharmacokinetics), PMC2689518 (human cannabinoid pharmacokinetics), Deurenberg body composition formula.