What do bid, tid and qid mean on a prescription label?
On a prescription label, bid means twice a day, tid means three times a day and qid means four times a day; prn means as needed and po means by mouth. They are Latin shorthand, and the National Institute on Aging (2022) publishes the same short list for older adults and the people who help them, with one firm tip: ask your pharmacist to explain any term you do not understand.
The shorthand tells you how often. It does not tell you which clock times, and it never replaces the pharmacist's instructions. That part is a two-minute conversation at the counter.
| On the label | Plain English | Latin | Note |
|---|---|---|---|
| bid | twice a day | bis in die | NIA |
| tid | three times a day | ter in die | NIA |
| qid | four times a day | quater in die | NIA |
| qd | every day | quaque die | NIA · easy to misread |
| qod | every other day | – | easy to misread |
| prn | as needed | pro re nata | NIA |
| po | by mouth | per os | NIA |
| ac | before meals | ante cibum | NIA |
| pc | after meals | post cibum | NIA |
| hs / qhs | at bedtime | hora somni | NIA · easy to misread |
| ea | each | – | NIA |
| Rx | prescription | – | NIA |
| q4h, q6h, q8h | every 4, 6 or 8 hours | quaque … hora | standard shorthand |
| tab / cap | tablet / capsule | – | standard shorthand |
| gtt | drops | guttae | standard shorthand |
| OD / OS / OU | right eye / left eye / both eyes (OD can also mean once daily) | – | easy to misread |
| U, IU, cc | unit, international unit, cubic centimeter (mL) | – | easy to misread |
Easy to misread means the abbreviation appears on published lists of error-prone shorthand: qd can be read as qid, hs as half-strength, OD as right eye, U as a zero (Cao, Taylor and Vidimos, Dermatology Online Journal (2010)). If you see one, ask the pharmacy to write the words out. That is a normal request.
Prescription abbreviation questions, answered
What does bid mean on a prescription?
Twice a day. It comes from the Latin bis in die. The National Institute on Aging (2022) lists it with tid (three times a day) and qid (four times a day). Which two clock times to use is a question for the pharmacist.
What is the difference between qd and qid?
qd means every day (once); qid means four times a day. Because a badly written q can turn one into the other, qd appears on published lists of error-prone abbreviations, with "daily" as the safer wording (Cao, Taylor and Vidimos, Dermatology Online Journal (2010)).
What does prn mean on a pill bottle?
As needed. The medicine is not on a fixed schedule. The National Institute on Aging (2022) suggests asking the pharmacist what "as needed" means for that specific medicine.
What do ac and pc mean?
ac means before meals and pc means after meals (National Institute on Aging (2022)). Ask how long before or after if the label does not say.
What does hs or qhs mean?
At bedtime. Safety reviews note hs can be misread as half-strength and qhs as every hour, so the safer wording is simply "bedtime" (Cao, Taylor and Vidimos, Dermatology Online Journal (2010)).
Can DoseBeacon read my prescription label?
It can scan a pharmacy label and create a draft using on-device text recognition. You then check every field before any reminder turns on. It does not decode Latin shorthand for you, which is why this page exists.
Does DoseBeacon tell me how much to take?
No. DoseBeacon is a reminder and record-keeping app, not a medical device. It never recommends doses. If you are unsure about a dose, ask a pharmacist or prescriber.
Label shorthand vs a reminder in plain words
A bottle is written for the pharmacy. A reminder should be written for the person holding the pill.
On the bottle
Metoprolol 25 mg
1 tab po bid pc
Qty 60
On the DoseBeacon card
Morning heart pill
Metoprolol 25 mg · Take 1 tablet
Take with breakfast · With food
The card shows what you type in, in your own words. That is the example from the app's store screenshots, using made-up people and medications.
How to turn a label into reminders in 3 steps
- Decode it. Use the table above, then confirm clock times with the pharmacist. "Twice a day" might mean breakfast and dinner, or every 12 hours.
- Scan and check. DoseBeacon scans a pharmacy label into a draft with on-device text recognition. You check every field before any reminder turns on.
- Answer the reminder. Senior Mode shows one large card at a time with four choices: Log as taken, Later, Not sure and I need help.
Who DoseBeacon is not for
- Anyone hoping an app will say how much to take. It never recommends doses.
- Android households. DoseBeacon is iPhone and iPad only, and each helper in a Care Circle needs it on an iPhone or iPad.
- Someone on one daily pill who never forgets. A phone alarm is enough, honestly.
- Families who need proof a pill was swallowed. A logged dose is a report, not proof.
Free covers reminders, one patient, two active medications, one helper, full history, reports and the emergency card. DoseBeacon Family ($8.99/month or $59.99/year) adds unlimited active medications, more caregivers and the Dose Handshake.
A Sunday at the kitchen table
A new bottle comes home after a check-up: 1 tab po bid pc. Nobody at the table is sure what pc means. The decoder says: one tablet, by mouth, twice a day, after meals. A quick call to the pharmacy settles the times: after breakfast and after dinner. The medicine goes into DoseBeacon as "Morning heart pill, take with breakfast" and an evening twin.
One design decision we made for moments like this: if nobody reports a dose, the record says "Not confirmed yet", never "missed". Guessing is how double doses happen; an honest blank is safer.
Inside DoseBeacon
Try it tonight
Decode one bottle, add it to DoseBeacon, and let tomorrow's reminder speak plain English. This is general information, not medical advice. Talk to your clinician or pharmacist.
Related
- DoseBeacon: large-text pill reminders with a family Care CircleLarge-text pill reminders for aging parents, plus a shared record of reported doses for family helpers. Free on iPhone, works offline.
- Can't remember if you took your medication? What to do nowNot sure you took your pill? Why doubling up is the risky move, what NHS pharmacy guidance says, and how to stop the doubt tomorrow.
- Medication checklist after hospital discharge, with a list-compare toolWhat to do with a parent's pills in the first 48 hours home: a 9-step checklist and a tool that compares the old list with the discharge list.
- How to prevent double dosing at home: six mistakes and fixesSix everyday mistakes that lead to a double dose at home, and the fix for each. Pick your household setup and see the one check that matters most.