, with added zinc 15mg which contributes to the maintenance of normal testosterone concentrations relevant levels of the important bioflavonoid quercetin, 3 important amino acids alanine glycine & glutamic acid supplied in their free form for easy absorption., no-quibble money back guaranteeprostex® has been reformulated to include a higher level of beta sitosterols from a natural plant source. this plant source has enabled us to add a significantly higher level of these important ‘actives’ than was in the original prostex® formula & a level which matches current research.a full 320mg of extract of beta sitosterolswe’re pleased to say that we insist on the highest strength concentrated extract where the beta sitosterol level is standardised to provide the full 320mg of these ‘active’ compounds (in 2 tablets). many similar products contain less than half this amount! twice the nrv* for vitamin d we’ve taken the opportunity to add a decent level of vitamin d (10µg per 2 tablets) recognising the important role it plays in the normal function of the immune system & healthy inflammatory response. * nrv (nutrient reference value)with added zinc & pure quercetin. a healthy level of zinc at 15mg which contributes to the maintenance of normal testosterone concentrations in the blood & the protection of cell constituents from oxidative damage. & a relevant level of the important bioflavonoid quercetin in each tablet.