Kratom is the name given to the leaves and tree preparations from the Mitragyna species Korth, a native tree to South Africa and South East Asia. In 2012, Kratom was one of the most common ‘legal highs’ sold online in Europe, followed by synthetic cathinones. Low doses produce a stimulant effect whereas high doses produce a sedative effect. The leaves from the rubiaceous plant Mitragyna speciosa have been used for their opium-like effects and several alkaloids have been derived from the leaves. Mitragynine, the main active component of kratom, acts on the μ and δ – opioid receptors. At low doses, mitragynine acts on the δ receptors and at higher doses, it crosses over to act on the μ opioid receptors.
