RCS-4

RCS-4, or 1-pentyl-3-(4-methoxybenzoyl)indole, is a synthetic cannabinoid drug sold under the names SR-19, BTM-4, or Eric-4 (later shortened to E-4), but originally, OBT-199.

Pharmacology

RCS-4 is a potent cannabinoid receptor agonist, with EC₅₀ values of 146 nM for human CB₁ receptors, and 46 nM for human CB₂ receptors. All methoxyphenyl regiosiomers, and N-butyl homologues of RCS-4 and its regiosiomers also display potent agonist activities at CB₁ and CB₂ receptors.

Legality

RCS-4 was banned in Sweden on 1 October 2010 as a hazardous good harmful to health, after being identified as an ingredient in "herbal" synthetic cannabis products.

It was outlawed in Denmark on 11 March 2011.

In August 2011, New Zealand added not only RCS-4 but also its 1-butyl homologue, and the 2-methoxybenzoyl isomers of both these compounds, to a temporary class drug schedule (i.e. equivalent to Class C but reviewed after 12 months, and with personal possession and use of small amounts decriminalised), which was newly created under the Misuse of Drugs Amendment Act 2011 passed a week earlier.