yok4dYok3D ® is the ultimate non-stimulant Nitic Oxide stimulator developed by USP Labs. The main ingredient in Yok3D ® is Inositol-stabilized Citrul Silicate (Citrul Silicate as Nitro-Rx ®), a proprietary complex of bonded arginineDescription Yok3d from USP Labs is a supplement desned to optimize blood flow for a sustained muscle pump. It is formulated without caffeine for a side-effect-free experience.