Shilajit: Ancient Remedy or Modern Marketing?

Shilajit is a blackish-brown sticky tar that seeps out of cracks in high-altitude mountain rocks. It forms over centuries as plant matter is squeezed and partly broken down between layers of stone. In Ayurvedic medicine it is classified as a rasayana, or rejuvenating substance. In the modern Western supplement market it is sold as a testosterone booster, energy aid, and anti-aging product at $50–$100 per month. The human evidence does not support most of those claims.

What It Contains and the Clinical Gap

Purified shilajit contains fulvic and humic acids (40–60% of content), dibenzo-alpha-pyrones, and a large number of trace minerals in ionic form (Carrasco-Gallardo 2012 PMID 22216264). The human trials are small, mostly funded by ingredient manufacturers, and inconsistent. A 2010 Andrologia RCT (Biswas 2010 PMID 19854048) tested processed shilajit in 60 infertile men and reported improved sperm count and motility — a result in a clinical population, not in healthy men. A follow-up open-label study in 28 oligospermic men found modest testosterone, FSH, and LH changes after 90 days of 100 mg twice daily (Pandit 2016 PMID 26395129). A 2019 Journal of the International Society of Sports Nutrition trial in healthy resistance-trained men (Keller 2019 PMID 30290359) reported small improvements in muscle strength but did not measure testosterone as a primary outcome. There is no high-quality RCT showing shilajit raises testosterone in healthy eugonadal men. The total clinical database is too small to support most of the marketing claims.

Contamination Risk

Raw or poorly purified shilajit can contain meaningful amounts of heavy metals — arsenic, lead, mercury, and cadmium — that reflect the geology of the rock it seeped out of (Wilson 2011 PMID 21470302). Purification quality varies a lot between brands, and unlike most plant-based supplements, shilajit has no formal pharmacopeial standard. The U.S. Pharmacopeia heavy-metal limits for dietary supplements (USP General Chapter <232>) cap daily oral lead at 5 µg and arsenic at 15 µg; older Indian Ayurvedic preparations including some shilajit products have exceeded those limits in independent surveys (Saper 2008 PMID 18728265). Independent third-party testing — or a USP- or NSF-verified product — is important before use.

Bottom Line

Marketing claims for shilajit — testosterone boosting, energy, anti-aging — outpace the clinical evidence by a wide margin. The contamination risk gives a second reason for caution if you cannot verify how a product was tested.