Does use of mephedrone (meow meow/ mcat) cause impotence? is the impotence permanent? i have been a user for the past 4-5 months.

It could be: the only way to tell for sure is to stop the ephedrine (ephedrine sulfate) and see a physician to rule out other reasons for impotence

Here are some ...: His drug is a central nerve stimulant similar to cocaine, heroin, methylamphetamine, etc. which may result in a wide range of side effects including altering sexual performance of various degree among its user. Will its adverse effect be permanent? If you wish to better, just stop its use with a determining will & disregard symptom versatility. Stopping its use now; that is only choice you've.