I use 250mg Shiljit ext. since about 2012. The cheep kind from India considered contaminated. And my 5 hair tissue mineral analysis since then showed half my heavy metals in hair actually got less. Only Uranium increased just above normal range for 2 years, and decreased again. But that's also confounded, for example by having yearly vacations just 20 kms from an Indian atomic power plant, and Fukushima.
Shilajit is made of hummus (60 – 80%) and organic plant materials that have been compressed by layers of rocks over time. High pressure and blazing heat metamorphize these organic compounds. The warmer temperatures in the summer melt Shilajit, causing it to ooze from cracks in the rocks .
Over 84 types of minerals, including most essential minerals
Fulvic acid, the main active ingredient
Humic acid (and uronic acids)
Other plant and microbial metabolites (such as dibenzo-alphapyrones)
Small peptides and amino acids
The exact composition of Shilajit is influenced by factors such as [2+]:
Plant varieties that get incorporated into its mass (Sullu spurge, white clover, liverworts, mountain mosses, and others). Mosses are especially rich in minerals and metals such as copper, silver, zinc, and iron...
Proper Purification vs. Low-quality Products Shilajit in its natural form (so-called “native Shilajit”) is often contaminated by varying mycotoxins, heavy metals, free radicals, and other potentially hazardous compounds [2+]...
The government of Canada warned consumers in 2005 not to use Shilajit, as Indian Ayurvedic Products were found to contain dangerously high levels of heavy metal (such as lead, mercury, and arsenic). Measures were taken to remove most of these products from the market, especially those produced by Dabur India Ltd.