O.P.M.S. Silver Kratom Capsules The O.P.M.S. half gram capsules of Silver Mitragyna Speciosa (Kratom) from O.P.M.S. All O.P.M.S. products are all-natural and never adulterated. O.P.M.S. Gold and Liquid products utilize an all-natural process that is specifically designed to preserve the delicate nature of the plant’s alkaloids through out the extraction process.