NOW Magnesium Inositol Relax Powder combines magnesium and inositol, two nutrients that support relaxation and a normal mood. Magnesium is a mineral that is critical for metabolism, energy production, nerve impulse transmission and more. Inositol is a member of the B-complex family that's found in all cell membranes, especially in the brain and central nervous system, where it plays an important role in neurotransmitter signaling. Natural color variation may occur in this product. This product is sold by weight not volume.