Tavul
As-needed medication
Track as-needed (PRN) medication on iPhone
Last updated: October 30, 2026 · By Oleksandr Tarabaka, Tavul developer
Tavul is a free iPhone and iPad app for tracking as-needed medication. Record a dose when you take it, and Tavul shows how long ago that was, counts down the interval you set, and compares your recorded doses with your 24-hour limits. You choose those numbers, based on your clinician’s instructions or the label.
What does as-needed (PRN) mean?
PRN is short for the Latin pro re nata, “as the situation requires.” An as-needed medication has no fixed time. You take it when a symptom or situation calls for it, within the directions from your clinician or the label.
What Tavul tracks for as-needed doses
The interval. Enter the minimum time between doses, and Tavul counts down from your last recorded dose.
24-hour limits. Set a maximum number of doses, a maximum total amount, or both. Tavul checks each one separately against your history.
Earlier doses. Forgot to log one? Add it at the time you took it, and Tavul recalculates the interval and limits. Editing or deleting a dose updates them too.
Why Tavul uses a rolling 24-hour window
A calendar day resets at midnight. A rolling window looks back exactly 24 hours from now, so doses at 11:00 PM and 12:10 AM both count. Tavul measures elapsed time, so daylight saving and time zone changes do not shorten an interval.
Tracking products with the same active ingredient
The FDA notes that acetaminophen is found in hundreds of over-the-counter and prescription drugs. If you enter the same active ingredient for your as-needed medications, Tavul can count those doses together against a shared limit. This relies on what you enter, because Tavul has no drug database.
What Tavul does not do
Tavul does not tell you what to take, how much, or whether a dose is safe for you. It does not check drug interactions or diagnose anything. It compares your records with the settings you entered. Agree on doses, intervals, and combinations with your doctor or pharmacist.
Where your history goes
Your records stay on your device, with no account to create, and tracking works offline. You can export a CSV of your intake history to share with your clinician, or a JSON backup to restore in Tavul.
Tavul is a tracking tool, not medical advice. It does not determine whether a medication or dose is safe for you. Follow your clinician’s instructions and the medication leaflet.
Download on the App Store