High Dose Selenium Significantly Improves My Fatigue and Brain Fog High dose selenium significantly improves my fatigue levels, and noticeably reduces my brain fog. I have consistently found selenium to be the best single supplement or drug I have tried for ME/CFS. I found that it requires a high(ish) dose of 400 mcg of selenium each day before these benefits manifest. The best form of selenium to take is yeast-free selenomethionine, as selenomethionine the best absorbed form of selenium. Selenium must be taken on an empty stomach, to ensure it is properly assimilated. I found that the improvements in fatigue and brain fog that selenium provides take a while to appear: it takes around 10 days of daily selenium supplementation before these improvements manifest. But these improvements begin to be noticeable by the 10 day stage. This amelioration in fatigue and brain fog is also maintained permanently, provided I continue to supplement with 400 mcg of selenium each day. Two other people who followed the same selenium protocol as me also said that they found noticeable improvements by 10 days. If I cease taking my daily dose of 400 mcg selenium, within about 3 or 4 days of stopping, my fatigue and brain fog will begin to get worse again. If you want to maintain the increased energy and cognitive abilities it provides, one should take selenium on a daily basis. I also found that if I reduce my dose to 200 mcg of selenium a day, the fatigue and fatigue and brain fog also creep back to some degree. Taking a 400 mcg daily dose of selenium seems to provide the best benefits. The maximum daily dose of selenium is 600 mcg (ref: here), so you can even try taking higher daily doses of selenium; but I personally found that these higher doses created some irritability side effects, so I went back to 400 mcg. However, other people may be perfectly fine with these higher doses. High Dose Selenium: Long Term Improvements in ME/CFS This daily dose of 400 mcg of selenium also appeared create to some significant long term improvements in my ME/CFS. Two years ago, my ME/CFS was much worse than it is now: at that time, for one or two days each week, it was common for me become so tired I would sleep in bed for 18 hours of the day. Nowadays, however, I never experience these very tired days, and my overall energy levels and mental concentration levels are much improved compared to two years ago. So something has caused my ME/CFS to get significantly better over the last two years. The only three supplements I have consistently taken every day over the last two years are: 400 mcg of selenium, 750 mg of N-acetyl-glucosamine, and 800 mg of horsetail herb (a source of silica). However, since the selenium supplement noticeably improved my energy levels and brain fog even in the short term (as mentioned, these improvements appear after 10 days of daily selenium), I suspect selenium is also responsible for the substantial long term benefits I experienced in my ME/CFS over the last two years. Anyone with ME/CFS looking for a sustainable gain in energy and improvement in brain fog might want to try taking 400 mcg of selenium (as yeast-free selenomethionine) on an empty stomach for 10 days or so, and see if you experience the same benefits as I did. If this high dose of selenium does provide you with noticeable improvements in your ME/CFS symptoms after 10 days, I suggest you stick with this supplement, as you may reap even further long-term improvements after a year or two on high dose selenium. Notes • Other forms of selenium supplement include sodium selenate, and sodium selenite, but the absorption of these two forms in the gut is only around 50%, whereas the absorption of selenomethionine in the gut is near 100%. If you take the less absorbable forms of selenium, you may have to increase your dose to compensate for the poorer assimilation. • Selenomethionine comes in both a yeast-free form, and a yeast-derived form. I would avoid the yeast-derived form of selenomethionine, because I found this yeast form caused significant depression symptoms when I took it, whereas the yeast-free selenomethionine had no such side effects. • Selenium must be taken on an empty stomach to ensure it is well absorbed. • Selenomethionine in supplements is also referred to as L-selenomethionine. • Selenium protects against cancer, so this is another benefit of taking this supplement on a daily basis. Though it may increase the risk of prostate cancer.1 High Dose Selenium Benefits: Mechanisms of Action Selenium has a number of effects in the body that may explain why it reduces fatigue and brain fog in ME/CFS. Some of these effects are as follows: ➤ Selenium has significant antiviral effects, as selenium deficiency is known to cause increased viral pathogenicity, and is known to make coxsackievirus B and echovirus infection more severe (coxsackievirus B and echovirus are two enteroviruses strongly linked to ME/CFS). See these studies: • Selenium and viral virulence (full paper here) • Increased virulence of a human enterovirus (coxsackievirus B3) in selenium-deficient mice • Increased virulence of coxsackievirus B3 in mice due to vitamin E or selenium deficiency • Selenium deficiency contributes to the chronic myocarditis in coxsackievirus-infected mice • Coxsackievirus B3-resistant mice become susceptible in Se/vitamin E deficiency • Benign human enterovirus becomes virulent in selenium-deficient mice • Selenium deficiency and viral infection • Selenium and host defence towards viruses • Selenium and vitamin E status: impact on viral pathogenicity ➤ Selenium increases toxic metal excretion from the body. Supplementation with just 100 mcg of selenium (in the form of selenomethionine) daily for 4 months led to a 34% reduction in levels of mercury detected in body hair. Selenium may act as a competitive inhibitor of mercury and lead absorption. Selenium also mitigates the toxicity of mercury and cadmium by modulating their interaction with certain biomolecules. Source: Heavy Metal Detoxification ➤ Selenium is a co-factor for glutathione peroxidase, which is an antioxidant enzyme that, with the help of reduced glutathione, scavenges hydrogen peroxide. This helps prevent the generation of free radicals and reactive oxygen species (ROS) by hydrogen peroxide. ➤ Selenium deficiency increases susceptibility to glutamate-induced excitotoxicity. Ref: here.