Built by a licensed pharmacist

See How Drugs Move
Through Your Body

Visualize drug absorption, half-life, and elimination with beautiful, interactive simulations. Explore 35+ common drugs with clinically accurate data.

35+ drugsFree foreverNo account neededClinically accurate
t½ ≈ 5 h

Caffeine 200 mg — elimination over 20 hours

0 h
200 mg
5 h
100 mg
10 h
50 mg
15 h
25 mg
20 h
12.5 mg

Each half-life removes 50% of the remaining drug. After five half-lives (≈25 h for caffeine), <3% remains — considered clinically eliminated.

Pharmacokinetics made visible

35+ Common Drugs

From caffeine to prescription medications, explore accurate half-life data sourced from clinical pharmacokinetic references.

Multi-Dose Simulation

See how drug levels build up with repeated dosing and reach steady state — the way pharmacists actually think about it.

Built by a Pharmacist

Every calculation is backed by real pharmacokinetic data and clinical knowledge, not guesswork or Wikipedia.

Clinical Accuracy

Half-life values are drawn from peer-reviewed literature and standard references such as Goodman & Gilman and Clinical Pharmacokinetics.

Three steps to understanding

01

Pick a Drug

Choose from 35+ common medications or enter a custom half-life value.

02

Set Your Schedule

Define dose amount, frequency, and number of doses to simulate.

03

See the Science

Watch an interactive concentration-time curve render in real time.

Common drug half-lives at a glance

Half-life values from peer-reviewed pharmacokinetic literature. Click any drug to simulate it.

DrugHalf-LifeDosing FrequencyCategorySimulate
Caffeine3–7 hAs neededStimulantView →
Ibuprofen2 hQ6HPain ReliefView →
Acetaminophen2–3 hQ4–6HPain ReliefView →
Aspirin0.25 h*VariesPain ReliefView →
Fluoxetine1–6 daysDailyMental HealthView →
Amoxicillin1.5 hQ8HAntibioticView →
Warfarin20–60 hDailyCardiovascularView →
Metformin4–9 hQ12HMetabolicView →

* Aspirin's pharmacological effect lasts far longer than its 15-minute plasma half-life because it irreversibly inhibits COX enzymes. Platelet effects persist for the platelet's entire 7–10 day lifespan.

Start with something familiar

Caffeine5–6 h

The world's most used stimulant. Found in coffee, tea, and energy drinks.

Acetaminophen2–3 h

Common pain reliever sold as Tylenol. Rapid onset, moderate duration.

Ibuprofen2 h

NSAID anti-inflammatory. Short half-life means frequent dosing.

Fluoxetine1–6 days

Antidepressant (Prozac). Exceptionally long half-life simplifies dosing.

Melatonin30–60 min

Sleep hormone. Clears quickly — timing your dose matters.

Ethanol~4–5 h

Alcohol metabolism follows zero-order kinetics at typical doses.

Alprazolam6–27 h

Benzodiazepine (Xanax). Intermediate half-life in the benzo class.

Amoxicillin1.5 h

Broad-spectrum antibiotic. Short half-life drives the Q8H dosing schedule.

Warfarin20–60 h

Anticoagulant with wide half-life variability due to genetic polymorphism.

Explore All 35+ Drugs in the Simulator

Understand the science

Pharmacist-written guides that explain the concepts behind the simulator, without the textbook jargon.

01Basics

What is Drug Half-Life?

The foundational concept explained simply: what the t½ number means, why it matters for dosing, and how your body eliminates drugs.

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02Concepts

Pharmacokinetics 101

Absorption, distribution, metabolism, excretion — the four pillars of pharmacokinetics and how they shape the concentration-time curve.

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03Dosing

Understanding Steady State

Why drugs need several doses to reach stable blood levels, and how half-life predicts exactly when that happens.

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04Deep Dive

The Science Behind Caffeine

A deep dive into caffeine pharmacokinetics: why your afternoon coffee disrupts sleep, and what a 5-hour half-life really means in practice.

Read article →
View all 8 articles →

Ready to see the science?

No account required. No download. Open the simulator and start exploring exactly how medications behave inside the body.

Start ExploringRead the Guides