Mephedrone molecule. Molecular model showing the structure of the stimulant Mephedrone. Atoms are represented by spheres (carbon: light blue, nitrogen: dark blue, oxygen: orange, hydrogen: green). Mephedrone is increasingly being used recreationally as a substitute for illegal drugs that have similar effects, such as ecstasy. It is currently legal to own and use in the UK (as of early 2010) but has been banned in a number of countries, including Australia, Denmark and Germany. Little is yet known about it's pharmacology and toxicology.