As I'm sure you know the concentration of active alkaloids (mescaline) in any species varies greatly from specimen to specimen. But in general, it is thought that T. peruvianus has perhaps an average of 2-4x the mescaline content of common T. pachanoi (San Pedro), and just slightly higher concentrations than the most potent San Pedro specimens. Unfortunately, there is only a small amount of testing data available, too little to verify this common wisdom (see "A Look at the Mescaline Content of T. peruvianus and T. pachanoi" for more information).