Parents: Have You Heard of 7 OH? A new substance called 7 OH ( 7 Hydroxymitragynine) is starting to appear in gas stations, vape shops, and online stores, and many people don't realize the risks. 7 OH, kratom removed in Florida. What to know about addictive drug Today, we announced the issuance of seven warning letters to companies illegally marketing products containing 7 hydroxymitragynine (7 OH). https: www.fda.gov news events press announcements fda issues warning letters firms marketing products 7 Oh Mitragynine Vape What is 7 OH? 7 OH stands for 7 Hydroxymitragynine. It is a strong chemical found in very small amounts in the kratom plant. Some products sold in stores have much Operation Vape Trail' cracks down on synthetic marijuana, 7 OH, kratom, more