The Substance
Salvinorin-A is the psychoactive ingredient in Salvia Divinorm. It also one of the stronger naturally occuring hallucinogenic compounds around. But, before you get to worked up, in the concentrations of the chemical in leaf, and even 5x-25x dried leaf is relatively low, approximately 0.89 mg per gram of dried leaf to 3.70 mg/g. Un/fortunately Salvinorin-A is alcohol soluble, and using only basic kitchen equipment it can easily be distilled (very sophisticated measuring equipment is needed to get the correct dosage of crystals). Although, because of the intensity of the effects, it must be known that this should not be used as a recreational substance, defiantly not something to do at a large party/concert etcetera.
The Effects
In pure samples it becomes psychoactive at 200 - 500 mcg, producing a detached feeling, and closed (occasionally open) eye visuals, with the effects becoming disturbing and unpleasant at 500 - 1000 mcg. Unfortunately it is very difficult to gauge how much Salvinorin-a you have ingested while smoking it. It has a relatively high boiling point, this means that with a standard butane lighter flame, it may/may not be vaporized (or will be in varying amounts). Also, it may condense back into a solid before it reaches your lungs. Because of this, some people end up taking more than is necessary and reporting a very unpleasant trip. Another thing to consider, is that the strength of 5x/10x/25x extract will vary wildly from different sources. A more sure-fire (although slower acting) way to get Salvinorin -A into your system is by chewing it, and holding it under your tongue (Sub-Lingual ingestion), this means that more of the good stuff gets into your system, but at a much slower rate.
Saying this, I have tried Salvia personally (smoked 10x extract) and have had wonderful results, Its not really the purpose of this node to describe my personal experience, but it is definably something I?d recommend for those interested in exploring their minds.
The Others
Salvinorin-a is very unusual as a hallucinogenic, it bears no resemblance to LSD, nor to the alkoid ethanogens its effects are likened to. It was first isolated as a compound in 1982, by Alfredo Ortega, who named it. Salvinorin-b was also isolated, but found to have no psychoactive effects. As recently as 2001, a further compound was isolated from Salvia leaf, Salvinorin-c which is at about 4% the concentration of Salvinorin-a in salvia leaf, it has been speculated that this may be even more powerful than A, but human bioassays are yet to occur.