Thebaine (paramorphine), also known as codeine methyl enol ether, is an opiate alkaloid, its name coming from the Greek Θῆβαι, Thēbai (Thebes), an ancient city in Upper Egypt.

[3] While thebaine is not used therapeutically, it is the main alkaloid extracted from Papaver bracteatum (Iranian opium / Persian poppy) and can be converted industrially into a variety of compounds, including hydrocodone, hydromorphone, oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine, butorphanol and etorphine.

[5] The 2013 US Drug Enforcement Administration (DEA) aggregate manufacturing quota for thebaine (ACSCN 9333) was unchanged from the previous year at 145 metric tons.

[9][10] The Canberra Times of 16 November 2022[11] reported that four batches of Hoyts brand poppy seeds were being recalled due to unusually high levels of thebaine, and that at least twelve people in New South Wales had required medical attention after ingesting them.

As of 15 November 2022, Food Standards Australia New Zealand (FSANZ) is coordinating a national recall of a number of poppy seed products due to the potential presence of thebaine.