“Refills: 2” on a label is a date in disguise. Put in when you last filled it, how many days each fill lasts and how many refills are left, and this turns it into the last day you are covered — and the day to ask for a new prescription so there is no gap.
Refills remaining
Refills left → last day covered
The prescription
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How it counts
The fill you have in hand covers its own days' supply, starting on the day it was filled. Each refill is assumed to be collected the day the previous fill runs out, so a 30-day fill on 1 October with 2 refills covers 90 days, through 29 December. Collect a refill early and the dates move earlier; the refill too soon calculator covers how early a plan will let you.
Refills expire
A refill on the label is not a refill forever. Prescriptions carry an expiry date, and a refill that would fall due after it cannot be filled at all. How long a prescription lasts depends on where you live and on what the medication is — controlled medications usually get less time and fewer refills — so the date to use is the one on your label or from your pharmacy.
That is why the expiry field matters: a 90-day supply with three refills looks like a year of cover, but if the prescription expires before the last refill is due, one of them is simply lost.
Ask before the last fill, not after
A renewal needs the prescriber, and prescribers need time — a request, a review, sometimes an appointment. The buffer is there so the new prescription exists before the last bottle is empty. Doz keeps each prescription as its own card with the prescriber and the course dates, and warns you while there are still pills left.
Common questions
How long will my refills last?
Add one to the number of refills remaining, for the fill you already have, and multiply by the days' supply. A 30-day prescription with 2 refills left covers 90 days from the last fill, assuming each refill is collected when the previous one runs out.
What happens to unused refills when a prescription expires?
They cannot be filled. A refill that would fall due after the prescription's expiry date is lost, and you need a new prescription from your prescriber to continue.
When should I ask my doctor for a new prescription?
Before the last fill runs out, with enough time for the request to be reviewed. A week ahead is a sensible default; more if your prescriber usually needs an appointment first.
One thing this cannot do
This is an arithmetic tool, not medical advice. It works out numbers from what you type in — it does not know your medication, your prescription, or what you should do if something goes wrong. Anything about changing a dose, spacing doses differently, or handling a missed dose is a question for your doctor or pharmacist.