Zinc sulfate heptahydrate is a hydrate that is the heptahydrate form of zinc sulfate. Zinc sulfate heptahydrate is a dietary supplement used for zinc deficiency and can also accelerate the rate of healing. It is also used in prepration of zinc tris(thiourea) sulphate (ZTS), a semiorganic nonlinear optic (NLO) material that may be useful in laser fusion experiments and in second-harmonic-generation (SHG) devices.