Caution: "X" extracts can be much more potent than regular leaf. They may be desirable for those who have not had success in smoking regular leaf, or they may be desirable for those who wish to minimize the amount of smoke that they inhale. However, due to the potency of such extracts, the intelligent user will always exercise extreme caution when working with these preparations. The doses with "X" extracts are small enough that many people choose to accurately weigh them out prior to consumption.

The first discussion that we are aware of relating information about fortified "X" ("times") extracts was on page 174 of Dale Pendell's 1995 book Pharmako/Poeia: Plant Powers, Poisons, and Herbcraft, wherein he states:
"An excellent product I call ‘4X' can be prepared by evaporating an ethanolic (or methanolic) extraction of the dried leaves, and sopping up the oily goo left over after evaporating or distilling off the solvent with ‘cleaned' leaves rubbed through a strainer. Use an amount of cleaned leaf equal to about one-quarter the original weight of the leaves extracted. The 4X enrichment is suitable for smoking in small pipes." If one is using straight (non-extracted) leaf at "about one-quarter the original weight of the leaves extracted" as Pendell describes, most people would consider this product to actually be a "5X," since it contained all of the virtues of the "four parts" of the original leaves, plus an additional "part" from the one-quarter weight of straight non-extracted leaf that was added back in.

Pendell's description eventually brought forth the entrepreneurial spirit in some folks, and by 1997 there were commercially-available "5X" products. Then later came the 6X, the 7X, the 10X, and—not to be outdone—one vendor offered an 11X, stating, "Yeah, but mine goes to 11." The "X" number is increased by adding less and less straight (non-extracted) leaf back into the equation. As the "X" factor increases, eventually this approach will no longer work, as there is too much gooey stuff and not enough dried leaf, making the extract harder to work with. A straight acetone-to-goo extract (with no leaf added back into it; just the goo) would be considered about a "25X" (based on an average extracted salvinorin A content of 2.5 mg per gram of dried leaf). While Pendell suggested ethanol (or methanol), current opinion is that acetone is a better solvent, since salvinorin A is more soluble in this.