Many of us here I think are having trouble wrapping our heads around the info that's spread over many threads and the recommendations have changed over time. I've attempted to condense the latest discussions down to just what someone with brain fog would need to know to get started. If I've gotten anything wrong or important info is missing please contribute to the thread. To start: “A low dose B-complex suitable for twice a day use without folic or folinic acid and without CyCbl is needed. A, C (minimum 5000mg), D, E, magnesium, zinc, calcium, selenium, chromium, trace minerals, lecithin (or variants), omega3 oils are all needed before starting the active b12 and folate.” A deficiency in any of these can prevent the protocol from being effective. For the multi B Freddd is currently using NatureMade B-Complex with C, product # 1338. (I suspect that magnesium l-threonate might be more effective for our purposes. It is said to be the only form that crosses the blood-brain barrier.) Once this basic supplementation is underway the “deadlock quartet” can be started: “1 - 1mg of Enzymatic Therapy B12 infusion or 1/4 of a Country Life Methyl B12 5mg product # 6304 (not their similar products), and 1/4 of an Anabol Naturals Dibencoplex Capsule or tablet, both held between cheek and gum for up to two hours to maximize absorption. It takes some practice. Longer contact to skin means more absorbed. (The Jarrow brand has ceased being effective for many here.) 2 - L-methylfolate, Metafolin is the one I've used and tested. I will be testing the new variety, Quatrefolic soon and have heard only good things about it. For starters, 400mcg twice a day (half a tablet twice a day) is a good place to start for many.” At this point many of us will experience a worsening of symptoms due to low potassium. THIS CAN BE DANGEROUS, EVEN FATAL. It’s important to have some form of potassium on hand before starting. Potassium interferes with methylfolate absorbtion so they need to be taken separately. Four doses/day of both methylfolate and potassium are preferable to one or two doses. As the B12s start to wake up the damaged nerves it’s common to experience a heightened perception of the senses, both positive and negative. If nerve damage exists in the brain there may be strong emotional and personality changes. All of these changes should become less noticeable with time. After potassium and methylfolate have balanced out carnitine can be added in the form of l-carnitine fumarate. Jarrow freebase liquid carnitine works well for many. It’s best to start at a very low dose and titrate up to avoid anxiety. Liquid carnitine is ideal for this.