(44.9 ± 3.7 mg/dL) and also versus the placebo group (42.7 ± 2.5 mg/dL at baseline vs 48.0 ± 4.9 mg/DL at 16 weeks). Other markers (inflammation, fasting glucose, resting heart rate, etc.) showed no significant changes between baseline and 16 weeks on either the placebo or the MSM groups with the exception of C-reactive protein levels, which were higher on the placebo group than on the MSM group at baseline and continued to increase up to the 16 weeks mark while showing a very slight decrease on the MSM group. However, the authors state they cannot explain why CRP levels were higher on the placebo group nor whether MSM may play a stabilizing role on CRP. The authors also state more and larger studies are required to establish the relationship between MSM and HDL. Safety The of MSM is greater than 17.5 grams per kilogram of body weight. In rats, no adverse events were observed after daily doses of 2 g MSM per kg of body weight. In a 90-day follow-up study, rats received daily MSM doses of 1.5 g/kg, and no changes were observed in terms of symptoms, blood chemistry or gross pathology. Extensive research in animal models indicates MSM has a very low toxicity when administered both orally and topically. In clinical trials, several studies reported minimal or absence of side effects after 12 weeks of dosing. Reported side effects from these studies included mild gastrointestinal issues, fatigue, and headache, although they did not appear to differ from placebo. A more recent 26-week study on large joint osteoarthritis observed no adverse events or abnormal changes in lab monitoring when taking 6 grams MSM per day. MSM is considered 'Possibly Safe' at therapeutic doses, although further research is still needed to assess its safety for long-term use. Osteoarthritis A review of two small randomized controlled trials of methylsulfonylmethane in osteoarthritis (OA) knee pain relief "reported significant improvement in pain outcomes in the treatment group compared to comparator treatments; however, methodological issues and concerns over optimal dosage and treatment period were highlighted." The two trials included 168 people, of whom 52 received MSM, either 1.5 g/day or 6.0 g/day. The review authors stated: "No definitive conclusion can currently be drawn" and there is "no definitive evidence that MSM is superior to placebo in the treatment of mild to moderate osteoarthritis of the knee." Subsequent to the 2008 review there