Vanadyl sulfate

Vanadyl(IV) sulfate, VOSO₄, is a blue crystalline solid that is normally stable in room conditions. It is a moderately strong reducing agent, being oxidized in acidic solution to the vanadyl(V) ion and in alkaline solutions to the vanadate ion, both of which are yellow-orange in colour. It is reduced by zinc amalgam to a mixture of green vanadium(III) and purple vanadium(II) ions. It is also used in conjunction with chromium picolinate in a sugar blocker. Here it is said to improve blood sugar levels, and thereby increase energy, although these statements have not been evaluated by the FDA.