Biotest Z-12 is an encapsulated, non-addictive formula that contains three anxiety reducing, sleep-inducing ingredients: 4-amino-3-phenyl-butanoic acid HCL (Ph GABA), L-theanine, 5-hydroxytryptophan (5-HTP). Biotest Z-12 provides a full night's sleep without the sleep "hangover" associated with virtually all other prescription or non-prescription sleep aids.Z-12 is also useful to people who might not generally have trouble sleeping, but who might occasionally need a guarantee of a good night's rest, like the night before an exam, a job interview, or athletic meet. Travelers might find it useful, too, in overcoming the first-night insomnia that often afflicts those who sleep in beds they're not accustomed to; & Z-12 is helpful for making an anxiety-packed day a lot more tolerable.