forms Oral forms are available in both standardized and unstandardized forms. Standardized products may be preferable considering the wide variation of the chemicals in the dried root, as noted above. When standardized, it is done so as a percentage of valerenic acid or valeric acid. In commonly used doses, valerian is recognized as GRAS in the United States. Adverse effects Because the compounds in valerian produce central nervous system depression, they should not be used with other depressants, such as ethanol (drinking alcohol), benzodiazepines, barbiturates, opiates, kava, or antihistamine drugs. As an unregulated product, the concentration, contents, and potential contaminants in valerian preparations cannot be easily determined. Because of this uncertainty and the potential for toxicity in the fetus and hepatotoxicity in the mother, valerian use is discouraged during pregnancy. Headache and diarrhea have occurred among subjects using valerian in clinical studies. Effect on cats Valerian root is a cat attractant in a way similar to catnip. Its roots and leaves are one of three alternatives for the one-third of domesticated or medium-sized cats who do not feel the effects of catnip. Floral asymmetry Valerian is unusual in having flowers with "handedness", that is, having neither radial nor bilateral symmetry. Invasive species Valerian is considered an invasive species in many jurisdictions outside its natural range, including the US state of Connecticut where it is officially banned, and in New Brunswick, Canada, where it is listed as a plant of concern. Image gallery See also Orvietan Spikenard Corvalol Notes References External links Valerian, National Center for Complementary and Integrative Health, US National Institutes of Health, October 2020 Valeriana Cat attractants CYP3A4 inhibitors Medicinal plants Anxiolytics Flora of Asia Flora of Europe Flora of Azerbaijan Flora of Armenia Flora of China Flora of Denmark Flora of Estonia Flora of Finland Flora of Georgia (country) Flora of Germany Flora of Great Britain Flora of Greece Flora of Ireland Flora of Italy Flora of Japan Flora of Latvia Flora of Lithuania Flora of Norway Flora of Portugal Flora of Romania Flora of Russia Flora of Spain Flora of Iran Flora of Turkey Plants described in 1753 Taxa named by Carl Linnaeus GABAA receptor positive allosteric modulators