If you have ever carefully observed any medical prescription, you must have seen one symbol ‘Rx‘. What we see on medicines and prescriptions usually as Rx is just an adapted form of this symbol.
The symbol simply means, ‘take this’. Where does the meaning originate? The symbol is actually the Roman capital letter R which stands for recipere. The word recipere is an imperative form of the verb ‘recipe’. So the entire symbol originates from the word ‘recipient’, making the symbol Rx a command, an instruction to ‘take this’ medicine. The word recipe continued to mean ‘medical prescription’ until the 1700s when it was applied to the methods of food preparation. The symbol dates back to the medieval times but has now come to mean ‘medicine’ or just ‘prescription’ generally.
If the symbol comes from the simple letter R, why is there a crossbar at the leg? Some believe the cross is the letter I that stands for Jupiter which is the king of Gods. Looking at the astronomical symbol of Jupiter, there is a striking similarity among both. If that is true, the command just means ‘take this and God help/heal you.’ Look at this symbol below, tilt it a bit, and you can see the similarity for yourself.
While the Jupiter symbol is one theory, it is believed the line was just to clarify that the R was a symbol.
The symbol of Jupiter is not the only one similar. Look at the Egyptian symbol Eye of Horus. Don’t they look alike?
The Eye of Horus was a symbol used in ancient Egypt to mean protection from evil and good health. Some pharmacies use the eye as their representative symbol, but there is very little evidence to support the theory that the symbol relates to the Eye of Horus.
Since the symbol was Medieval, we can not know for sure why it is the way it is, but it has now become popular in medical abbreviations. In the modern abbreviations, Dx for diagnosis, Bx for biopsy, Cx for cervix, Hx for history, Ex for examination are just a few of such examples.