Two studies have evaluated the effects of MSM on allergic rhinitis. A 2004 multi-centered, open-label clinical trial found that MSM reduced both upper and lower respiratory symptoms associated with seasonal allergic rhinitis (SAR), and increased energy levels. It found no significant changes in IgE levels, although the duration of the study was not likely long enough to see changes. An RCT evaluated three doses of MSM and found that a 3g daily dose was most effective compared to 1g or 6g per day. Daily use at 3g decreased allergy-associated symptoms, including itchy eyes, itchy nose, watery eyes, rhinorrhea, sneezing, and nasal obstruction. The 3g dose also improved peak nasal inspiratory flow (PNIF) indicating improved breathing. The study also evaluated an acute 12g dose and found significant improvements in all symptoms except itching eyes and sneezing, but not for PNIF.