Piracetam (sold under many brand names) is a nootropic drug in the racetams group, with chemical name 2-oxo-1-pyrrolidine acetamide. It shares the same 2-oxo-pyrrolidone base structure with pyroglutamic acid. Piracetam is a cyclic derivative of the neurotransmitter gamma-aminobutyric acid (GABA), originally marketed in 1971 by UCB Pharma. Presently piracetam is used in many European countries, Asia and South America. In the United States, it is not approved by the US Food and Drug Administration for any medical use and it is not permitted to be sold as a dietary supplement. In the UK, piracetam is prescribed mainly for myoclonus but is used off-label for other conditions. Evidence to support its use for many conditions is unclear. Piracetam's mechanism of action, as with racetams in general, is not fully understood. The drug influences neuronal and vascular functions and influences cognitive function without acting as a sedative or stimulant. It is hypothesized to act on ion channels or ion carriers, thus leading to increased neuron excitability. GABA brain metabolism and GABA receptors are not affected by piracetam. It has been found to increase blood flow and oxygen consumption in parts of the brain, but this may be a side effect of increased brain activity rather than a primary effector mechanism of action for the drug.