ARENA Capsules contains Methylcobalamin and Pregabalin. Methylcobalamin is the neurologically active form of Vitamin B12, used by the enzyme methionine synthase to turn homocysteine (HCY) into methionine. Methionine is further converted to the important methyl donor, S-adenosylmethionine (SAMe). Pregabalin is a structural analogue of the neurotransmitter gamma-aminobutyric acid (GABA).