Posinol is made with an extract from the leaves of Apocynum venetum L., a wild plant grown in Asia. Posinol™ contains no less than 4% of the flavonoid glycosides-isoquercitrin and hyperoside. Hyperoside is known to be most efficacious in mental relaxation and reducing blood pressure. It works with the brain's naturally-occurring chemicals called neurotransmitters, including norepinephrine and dopamine. Posinol™ differs from St. John's wort in that it does not contain hyperforin, an active compound that interacts with the metabolism of certain pharmaceuticals.
"An Asian botanical used for emotional well-being is Apocynum venetum L. In vitro trials suggest Apocynum venetum have significant antioxidant effects, which may inhibit lipid peroxidation in the central nervous system.20 Animal trials investigating the impact of the botanical extract have found it exerts antixolytic activity mediated by the GABAergic system,21 and also reduces norepinephrine and dopamine concentrations, similar to the action of imipramine.22 Further, studies have shown Apocynum venetum extract does not impact the CYP3A pathway the way St. John's wort does, eliminating the possibility of drug interactions.23 OptiPure offers a patented form of Apocynum venetum called Posinol™, which contains no less than 4 percent of the flavonoid glycosides isoquercitrin and hyperoside, which support mental relaxation. Case study reports, provided by the ingredient producer Tokiwa Phytochemical Co., show 50 mg/d of Posinol can help reduce symptoms of mild to moderate depression. Company studies also show Posinol shortens the immobility time in an animal model for antidepressant activity." - http://www.naturalpr...l-wellness.aspx
This is also supplied by Ecological Formulas.