What does PO mean on a prescription?
PO means by mouth. A medicine marked PO is swallowed — a tablet, capsule, or liquid taken orally rather than injected or applied to the skin.
- Means:
- by mouth
- From:
- per os
- Type:
- How to take it
- Also written:
- po, p.o., PO
What it means in practice
PO comes from the Latin per os, literally “through the mouth”. It tells you the route, not the timing, so it almost always appears next to a frequency abbreviation. In “PO BID”, the PO is the how and the BID is the how often.
Example on a prescription
Amoxicillin 500 mg PO TID x 7 days
Take one 500 mg amoxicillin tablet by mouth three times a day for seven days.
Commonly confused with
- PRPR is per rectum, not by mouth. A single letter changes the route completely.
- NPONPO is nil per os — nothing by mouth. It is the opposite instruction, used before surgery or procedures.
- SLSL means sublingual: the tablet dissolves under the tongue rather than being swallowed.
Frequently asked questions
Does PO mean I can take it with food?
No. PO only tells you to take it by mouth. Food instructions are written separately as AC (before meals) or PC (after meals), or spelled out on the label.
What does 1 tab PO QD mean?
Take one tablet by mouth once a day. 'Tab' is the form, PO is the route, QD is the frequency.
Is PO the same as oral?
Yes. PO and 'oral' mean the same route. Pharmacy labels increasingly print 'by mouth' instead of PO because plain wording causes fewer errors.
Related abbreviations
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This page explains prescription notation for general information. It is not medical advice and does not replace your prescriber or pharmacist. If a label is unclear or differs from what you were told, check with your pharmacy before taking the medicine.