I'm trying to avoid using OTC antihistamine medications for hay fever due to grass pollen this summer and am seeking a natural alternative. As someone who has studied nutritional medicine at degree level I know that in theory vitamin C and associated bioflavonoids (e.g. quercetin) have antihistamine properties - but I have not experienced this effect in practice.

Does anyone use vitamin C and/or bioflavonoids for the treatment of hay fever and what dosages are you using to get a therapeutic effect?