Since ZMA is a registered trademark of SNAC Nutrition (SNAC Systems Inc.) but not a patented formula, other manufacturers using the abbreviation for their products may introduce various formulae with different chelated or other compounds (such as citrate, gluconate, and oxide) of basic components (i.e. zinc, magnesium, and vitamin B6), additional ingredients (such as copper, melatonin, fenugreek, Tribulus terrestris, Suma root, and Mucuna pruriens) with properties that are supposedly synergistic with the basic components. Nevertheless, some manufacturers market products of a similar basic formula but do not use the trademark ZMA abbreviation. Furthermore, SNAC Nutrition itself has ZMA-5 (ZMA formula with 5-Hydroxytryptophan) marketed as a sleep enhancer and ZMA Nightcap (ZMA-based proprietary blend with 5-hydroxytryptophan) marketed as an anabolic mineral support.