English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

What do the letters "Rx" have to do with medicine prescriptions?

share|improve this question
Is this used in countries outside the US? – Steve Melnikoff Nov 19 '10 at 16:37
Yes it is. At least here in Argentina. As it's from Latin, it might be well spread across the world. – Petruza Feb 3 '11 at 20:21
up vote 3 down vote accepted

Rx means "prescription", for example an "Rx-only drug" is one available only on prescription. It is derived loosely from the Latin recipe, to take.


share|improve this answer
Side note: In German, "recipe" and "prescription" are identical words ("Rezept"). – balpha Nov 22 '10 at 12:29

It's because doctors have terrible handwriting...

No, actually, I think it stands for the Latin "recipe", a Latin imperative form meaning "take".

share|improve this answer
Terrible handwriting is a much better etymology for this :) – Joe Kearney Nov 19 '10 at 0:34
Yes, note the similarity between recipe, reception and receive. All related to take or receive. – Petruza Feb 3 '11 at 20:19

Rx was originally written (and still is preprinted on some prescription forms) as a ligature, consisting of an upper case R with a bar across its tail. The ligature was used as a time-saving abbreviation for the imperative Recipe "Take thou" because in the days before packaged medications, prescriptions were (and to some extent still are) written in Latin and Latin abbreviations, and their function was to direct the pharmacist to gather certain ingredients and combine them in a customized way.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.