Ketamine is a legal, safe and effective medicine used to treat a variety of mental health conditions. Ketamine has rapidly-acting antidepressant and mood-enhancing effects. It works by blocking the brain’s NMDA receptors as well as by stimulating AMPA receptors, which are thought to help form new synaptic connections and boost neural circuits that regulate stress and mood. Ketamine has also been shown to enhance overall neuroplasticity for lasting symptom improvement.