Quercetin, which is found in red grapes, red wine, apples, berries, and tea, is a potent antioxidant that has anti-inflammatory properties and has been shown to have health benefits for men with BPH (benign prostatic hyperplasia).
A study involving rats examined the impact of quercetin on inflammation induced by carrageenan versus rats that were not given quercetin. The results showed that quercetin modulated the inflammatory response in the rats compared with controls. (Morikawa 2003)
A more recent (2015) study examined the effectiveness of combining quercetin with tamsulosin (Flomax), a drug often prescribed to treat BPH. A significant side effect of tamsulosin is orthostatic hypotension (drop in blood pressure when standing from a seated or reclining position).
In this rat study, researchers discovered that combining quercetin with tamsulosin reduced the activity prompted by the drug that could lead to a drop in blood pressure. The authors concluded that “The strong pharmacodynamic interaction between the food supplement quercetin and tamsulosin underlines the potential of the impact of supplement-drug interactions that warrant more research.”
The suggested dose of quercetin is no more than 1 gram daily without consulting your healthcare provider.
Morikawa K et al. Inhibitory effect of quercetin on carrageenan-induced inflammation in rats. Life Science 2003 Dec 26; 74(6): 709-21
Vrolijk MF et al. The supplement-drug interaction of quercetin with tamsulosin on vasorelaxation. European Journal of Pharmacology 2015 Jan 5; 746:132-37