Tryptophan is alpha-aminoacid that is used in the biosynthesis of proteins. It is essential aminoacid in humans, meaning the body cannot synthesize and it must be obtained from the diet. Tryptophan is a precursor of serotonin, and as such is sold over the counter in many countries as a dietary supplement for use as an antidepressant, anxiolytic and sleep aid, however application of tryptophan in these indications is not approved by FDA.

Pirenzepine is a M1 muscarinic receptor antagonist, which is prescribed for the treatment of gastric and duodenal ulcer in Europe. The drug preferentially acts on the gastric mucosa to inhibit secretion of both gastric acid and pepsin. Experiment with healthy volunteers demonstrated that pirenzepine passes the blood-brain barrier, but only to a small extent.

Oxilofrine is a sympathomimetic used to treat hypotensive states, with cardiac stimulatory effects similar to those of ephedrine. It has never been approved for use in the USA as a prescription drug or as a dietary supplement. Oxilofrine has been found (1) to act predominantly as a beta1 agonist increasing the speed and force of heart muscle contraction (inotropic effects), specifically, increasing left ventricular ejection fraction and stroke volume; (2) to increase blood pressure; (3) to have variable effects on heart rate; and (4) to potentially increase oxygen uptake by the lungs.