What is Sulbutiamine?
Sulbutiamine is a nootropic, commonly known as Arcalion or Arcatamin, which is synthetically derived from thiamine (vitamin B). Sulbutiamine was discovered in Japan to provide a better alternative to thiamine in terms of drug uptake and circulation throughout the human body (pharmacokinetics). Though its clinical effectiveness is not well-established by experimental or trial studies, it is the only drug used for asthenia (abnormal physical weakness or lack of energy). Sulbutiamine can be used in enhancing memory, improving erectile function as well as reducing certain psychological inhibitions like fear, timidity, avoidance, shyness etc.
How does Sulbutiamine work?
Sulbutiamine crosses the blood-brain barrier and increases the thiamine level, even more effectively than thiamine itself. A number of derivatives of thiamine exist, but the advantage of this specific synthetic derivative of thiamine lies in the structures of its two molecules. Thiamine contains a positively charged part in its molecule which prevents it to diffuse across plasma membrane. Thus the blood-brain barrier prevents the thiamine to enter in brain and nerve cells. Whereas the sulbutiamine is a dimer of thiamine, or in other words, it is composed of two thiamine molecules. This makes the drug capable of dissolving in lipids and other non-polar solvents. Thus sulbutiamine is capable of crossing the plasma membrane and overcoming the blood-brain barrier.
Effects of Sulbutiamine
Sulbutiamine acts by a number of different mechanisms, all of which are initiated by increased production of certain chemicals and neurotransmitters. With the help of such mechanisms, sulbutiamine is reported to help in regulating sleep and therefore can help patients suffering insomnia. Moreover, facilitating the increase in memory, focus and learning. Some investigators have also reported that sulbutiamine can improve neuro-transmission and inter-neuron communication, therefore raising feelings of happiness and executive-level cognitive processes.
Depending on expectations, Sulbutiamine is usually combined with other supplements like those of the racetam family and other nootropics. It is usually recommended to take sulbutiamine with fish oil, milk and other fat-rich foods so that it can be absorbed rapidly and efficiently. Efficacy of the drug is also decreased with regular use and higher dosages may be required over time to get the desired effects. To avoid any dependency issues, it is suggested that sulbutiamine should not be used regularly. Sulbutiamine can be used in enhancing memory, improving erectile function  as well as reducing certain psychological inhibitions like fear, timidity, avoidance, shyness etc.
Studies on Sulbutiamine
Though its clinical effectiveness is not well-established by experimental or trial studies, it is the only drug used for asthenia (abnormal physical weakness or lack of energy). One study found evidence for neuroprotective effects of sulbutiamine .
Recommended Dosage / Usage Instructions
Optimum dosage can vary depending on body weight, biochemistry or medical conditions. However most sources suggest 200mg – 600mg spread accross a day.
Side-Effects of Sulbutiamine
Sulbutiamine is thought to be quite safe and no severe side effects have been reported. Some mild side effects including headache, nausea, skin rashes and agitation, are prone to occur when using higher dosages than recommended. If any of these side effects appear, administration of the drug should immediately be stopped and a physician should be consulted for further guidance.
A consultation with a physician is absolutely recommended for pregnant or lactating women before ingesting sulbutiamine.
 - Clinical efficacy of the drug enerion in the treatment of patients with psychogenic (functional) erectile dysfunction - http://www.ncbi.nlm.nih.gov/pubmed/15776829
 - Evidence for neuroprotective effect of sulbutiamine against oxygen-glucose deprivation in rat hippocampal CA1 pyramidal neurons - http://www.ncbi.nlm.nih.gov/pubmed/22040892