How long does methadrone stay in your system for?

Answer 1

apparently if you have a blood test it doesn't come up positive...

but i don't believe this, so just think of it as the same as most drugs... and most drugs stay in your system for 3 days

Answer 2

Mephedrone is a research chemical that is illegal for human consumption. It does not test positive on drug tests, although has been known to cause a false positive. If this happens, a lab test will come up negative.