MeCbl has promising mechanisms and positive preclinical data from two different ALS models. Unfortunately, the anecdotal data we found did not identify any clear specific benefit, and the best of three clinical trials was unable to show an overall difference in ALSFRS-R progression or survival between PALS treated with MeCbl and those treated with placebo (26). A sub-group of patients with very specific pretreatment progression rates of 1–3 ALSFRS-R points over 12 weeks, and very early disease (less than 12 months from symptom onset) may have had benefit (26). This finding needs to be replicated, especially since an earlier study suggested patients with longer disease duration were more likely to benefit (20). We would like to see a full traditional sub-group analysis (28) carried out on the data from the third trial (26). This sub-group analysis could then be used to design inclusion criteria for a new phase III trial comparing MeCbl 50 mg twice a week IM to placebo. The new trial could measure serum B12 and homocysteine, and have pre-planned sub-group analyses that are both logical and practical. While we wait for this, PALS who wish to try MeCbl are reminded that the above studies used very high, injected doses, which appear to be available only by prescription. Lower over-the-counter doses administered orally have not been studied. It is well established that over-the-counter oral supplements may be of poor and inconsistent quality (32). Some over-the-counter oral vitamin B supplements contain not only B12 but also B6, which in large quantities can be harmful to the nervous system (33).