Among the different medicines lauded in Ayurveda is a curious resin called shilajatu (‘shilajit’ in Hindi, pictured above), found as an exudate from steep rock faces in the Himalayan mountain range. Shilajatu is not only among the most unique of remedies utilized by Ayurveda, but among the most valuable as well. Shilajatu is found at altitudes of between 1000 and 5000 meters, typically when the hot summer sun beats down upon the rocks, causing the resin to liquefy and exude, and then harden again upon cooling. Similar exudates have also been found in other mountain ranges in what is called the Tethyan mountain system, including the Caucasus, Urals, Pamir, Hindu Kush, Karakoram, Tian Shan and Kunlun Shan ranges.
As its older common name of bitumen suggests, shilajatu was once thought to be the ancient fossilized organic material from what was once the coastline of the tropical Tethys Sea region that existed between the subcontinent of India and Eurasia some 200 million years ago. As the subcontinent gradually collided with Eurasia the ancient coastline and seabed of the Tethys was thrown up as the Himalayas and the plant material was compressed between the rocks, where it became fossilized. More recent research, however, has indicated that shilajatu is composed primarily of humus with other organic constituents, and is thus likely to be of relatively recent origin. Researchers have found the degraded components of several different medicinal plants in samples of shilajatu including Euphorbia royleana and Trifolium repens, leading to the idea that shilajatu is in large part derived from the humification of a variety of resin or latex containing plants.
A medieval Indian text called the Bhavaprakasha states that there are four types of shilajatu, each with a different medicinal activity. Sauvarna is reddish; rajata shilajatu is yellowish; tamra shilajatu is bluish; and lauha shilajatu is blackish. A much older classical text Charaka samhita classifies shilajatu based on the morphological features of the rock from which it exudes. Modern research supports these time-honored perspectives, as it appears that the composition of shilajatu is influenced by a variety of factors, including the particular humified plant species involved, the geological nature of the rock, local temperature, humidity and altitude.
According to Ayurveda, all varieties of shilajatu are pungent (kata) and bitter (tikta) in flavor. The Bhavaprakasha states that sauvarna shilajatu is also sweet (madhura) in flavor, whereas lauha shilajatu has a salty (lavana) flavor. As for the energy, or virya, only tamra shilajatu is hot (ushna) in nature, whereas lauha, sauvarna, and rajata varieties of shilajatu have a cooling (shita) energy.
Shilajatu is called tridoshaghna, meaning that it reduces and balances all three doshas. Specifically, shilajatu is used to enhance digestion, inhibit parasites, dispel mucus, resolve cough, alleviate dyspnea, clear skin issues, strengthen the kidneys, reduce obesity, promote healing, resolve poisoning, benefit the heart, enhance the intellect, boost fertility, and ameliorate the effects of aging. According to the Charaka samhita, “there is no disease in the world that cannot be cured by shilajatu”, when administered at the appropriate time, in combination with suitable medicines, and by using the proper method of preparation. Charaka further adds that by taking shilajatu the body becomes strong and sturdy, as if “made of stone”.
The chemistry of shilajatu is highly variable depending upon the where it was collected and the processing methods utilized. Early chemical research on crude shilajatu indicated a variety of constituents, including a mixture of organic constituents (e.g. benzoic acid, hippuric acid, fatty acids, resins, waxes, gums, albuminoids and vegetable matter) and inorganic constituents (e.g. calcium, potassium, nitrogen, silica, aluminum, magnesium and sodium). Further work concluded that crude shilajatu is composed upwards of 80% humus, decaying plant material acted upon by bacteria and fungi, and most notably, fulvic and humic acids. Recent analysis has yielded the presence of biphenyl metabolites including a benzocoumarin and low molecular weight oxygenated dibenzo-α-pyrones in shilajatu, as well as triterpenes, phenolic lipids, and additional trace minerals including antimony, cobalt, copper, iron, lithium, manganese, molybdenum, phosphorous, strontium and zinc.
While Ayurveda has utilized shilajatu as a medicine for thousands of years, medical researchers are only now just beginning to scratch the surface. Reflecting the traditional perspective that shilajatu is a medhya rasayana, a Sanskrit term that means to “rejuvenate the intellect”, medical research has demonstrated cognitive enhancing and nootropic effects shilajatu, as well as the ability to attenuate addiction and withdrawal. Likewise, research has validated the use of shilajatu in the treatment of diabetes and cardiometabolic disorders, reducing blood glucose, total cholesterol and triglyceride levels, while significantly enhancing “healthy” HDL levels.
Tradition in India states that humans first became aware of the benefits of shilajatu by watching wild animals such as monkeys utilize it as a food source. Shilajatu is generally regarded as being quite safe, but crude unprocessed shilajatu may contain mycotoxins from contaminating fungi such as Aspergillus niger, A. ochraceous and Trichothecium roseum. Unprocessed shilajatu may also contain free radicals in the humic constituents that increase in concentration with an increasing pH, and thus certain sources of shilajatu that tends to have a higher pH, such as that obtained from Russia, may be a less desirable source.
As the crude shilajatu is not considered fit for use as a medicament, a variety of processing techniques are utilized to both purify it and modify its therapeutic properties. According to both the Chakradatta and the Sharangadhara samhita, the crude shilajatu is powdered and then macerated in hot water (or a decoction of Triphala) for several hours. This maceration is then filtered and the liquid collected in an earthen plate and exposed to the sun until a scum begins to form on the surface. This scum is then skimmed off the surface of the liquid and dried in the sun until it forms a hard mass. This substance is now considered to be pure and can be processed further or “impregnated” by macerating the shilajatu in the decoction of different medications chosen specifically for their activities in particular diseases.
While shilajatu is now found in the North America, often marketed as a kind of “superfood”, most commercial sources of shilajatu do not undergo the specific processing techniques described by Ayurveda, and cannot be considered the authentic product. Instead, shilajatu supplements may be standardized to fulvic acid and dibenzo-α-pyrone content, which many researchers consider to be the active constituents. The problem with this assertion, however, is that both fulvic acid and dibenzo-α-pyrones are widespread in the soil, as metabolites derived from fungi, plants, and animal feces. Thus, what is called “shilajit” could be just about anything that is rotting in the dirt. Previous efforts to obtain accurate information on where resellers are obtaining their product, and how it is being processed, has not yielded any fruit, and as such, I have long avoided all shilajatu sold in the marketplace. To ensure the highest quality, any shilajatu I use in my clinical practice is always obtained from my physician colleagues in Nepal, that have been preparing shilajatu-based remedies as a continuous tradition for the last 800 years.
When it comes to therapeutic use, shilajatu is considered to be an important rasayana, or rejuvenative, used in the treatment of a wide number of conditions, to prevent illness, and to ward off the effects of old age. It is best known, however, as a treatment for madhu meha (diabetes mellitus), and for this purpose the Ashtanga Hrdaya recommends that it be macerated in a decoction of kapha-reducing herbs (i.e. the Asanadigana group of herbs). This preparation is taken as part of the diet along with the meat of desert animals and aged rice, in combination with rigorous exercise. Another common remedy in the treatment of diabetes is to combine shilajatu with “blood-cleansing” herbs such as triphala and guduchi.
The rich mineral content and sandhaniya (healing) properties of shilajatu make it a good choice when treating musculoskeletal disorders, including osteoarthritis and osteoporosis. It is also used as a specific in the treatment of paralysis, the Chakradatta recommending a combination of shilajatu, guggulu, and pippali with a decoction of Dashamula (the ‘ten roots’ formula). Shilajatu can be used in any disease, however, and as a rasayana it has a special ability to treat deficiency conditions, including reproductive problems. Shilajatu can be used as an adjunct to the primary treatment of conditions such as cancer, and to enhance the potency of other medicaments.
According to the Charaka samhita, the truly excellent benefits of shilajatu are only obtained when it is consumed at dosages that begin at one karsha, or about 12 g per day, for at least seven weeks. Most modern practitioners, however, typically start with a lower dose of 2-3 g, twice daily. In its soft resinous form, a pea-sized amount can be licked off a spoon, followed by a couple sips of warm water or milk as an anupana, or ‘vehicle’. In it’s dried form, shilajatu can be powdered and taken in capsules, simply held in the mouth until it dissolves, or melted in a little warm water or milk. Be advised, however, that shilajatu has a very strong flavor that is reminiscent of ashphalt, hence its original Latin name of ‘ashphaltum’. As such, it is recommended to start with a small amount, and gradually work your way up to a larger dose.