My dentist prescribed me tylenol with codeine. ive never taken codeine before so i wanted to google it & what came up was that the fda has banned tylenol with codeine. why? & why is it still allowed to be prescribed if its banned?

I am not sure if you got the right information. If a medication had been ordered and pharmacy filled it, the medication is not banned, especially a narcotic analgesic. In the USA, any medication which is not or no longer approved by FDA won't be available in the drug stores.

Google is not FDA knowledgeable or always up to date. I write prescriptions for Tylenol #3 when necessary, any drug not approved is not in a pharmacy formulary.

Tylenol with codeine has not been banned, but rather discontinued by the company that produces it. Janssen, inc. found that this product had too much liability associated with it (ie/ addiction, breathing problemsin children) to make it feasible for them to continue producing it. It was a business decision, the FDA has not banned this product in healthy adults.