Gugguls come from the resin of the Commiphora mukul tree that grows in northwest India. Gugguls penetrate deep into the tissues and help to mobilize lipids and excess fluids and that unique but unwanted substance referred to in Ayurveda as ama, a kind of congesting phlegm-like metabolic residual. Gugguls are also anti-inflammatory. Gugguls are mixed with other herbs in traditional blends with the same names regardless of whether or not the formulas are exactly the same.
Shilajit is a little harder to explain, and it is almost a panacea in some circles. There are entire books on fulvic acid. Shilajit is created by run off in the Himalayas that deposits organic material into the crevices and fissures of stones. These are placed in the sun so that the resinous substance comes to the surface and melts. It is sometimes called bituminous pitch or asphaltum. It is dark red to brown to almost black in color and very bitter and is said to enhance the efficacy of any other formula taken.
Sanskrit texts refer to shilajit as the "conqueror of mountains and destroyer of weakness." Shilajit has a high mineral content; so prized was the herb in ancient times that no major disease was believed to be curable without this asphaltum. Despite the very ancient history of use of shilajit, very little is really understood about its exact origin, even whether it is a plant material or mineral. Most likely, its resinous nature is due to the presence of mosses that have contributed to the formation of shilajit.