Impact of the study: Given that L-cysteine is a natural (semi-essential) amino acid, converted to inert substance (MTCA) in the alimentary tract, it would comprise an ideal means to conduct migraine prophylaxis for years, without concern about the side effects that are inherent to many of the current treatment modalities. If the efficacy is proved in this formal RCT, the concept of using Acetium capsules in prophylactic treatment of migraines would represent a major step forward in a better clinical control of these frequently intractable syndromes.