"According to the latest information available, we simply don't know," concededed the late pharmacognosist Varro E. Tyler, Ph.D, who served as a professor emeritus at the Purdue University School of Pharmacy in Indiana.
We do know that valerian contains volatile oils, alkaloids, and unstable chemicals known as esters. Esters are lost when valerian root is dried and kept for extended periods. For that reason, the herb's effectiveness may vary considerably, depending on the quality of the brand.
Valerian contains chemicals with strong muscle-relaxant and sedative properties called valepotriates. All parts of the plant contain these chemicals, but they are most concentrated in the roots. Ironically, even valerian preparations without valepotriates have helped some people to fall asleep, raising the possibility that some still unidentified chemical, or a reaction amongst various compounds in the root, may produce a calming effect.
Animal studies conducted in the 1960s demonstrated that valerian acts as a powerful tranquilizer, and subsequent studies with humans replicated those effects. Valerian appears to work by affecting the central nervous system.
Researchers monitored electroencephalograph (a device that measures brain-wave activity) changes in rats that had been given a valerian preparation. They found significant sedative activity, recorded as an increase in brain waves associated with relaxation.
In another study, a tincture of valerian root was given to 23 hypertensive men. The preparation had a distinct tranquilizing effect, as measured by subsequent brain-wave activity.
Melatonin is another natural substance that may be used to treat insomnia. Continue to the next page to learn more.