Shilajit
Brief description
Shilajit is a sticky brown/black tar like substance found primarily from the layers of rock in the Himalayan, Tibetan and Altai mountains.
It has been used in traditional Ayruvedic medicine for thousands of years. It contains an important compound known as fulvic acid.
Evidence base
*Caution: Usually PreEventive will report outcomes based on multiple large studies (systematic reviews/SR), Shilajit has recently gained more popularity over the last 5-10 years, therefore, at the time of writing there are no good quality SRs present*.
Outcomes presented here are from randomised trials (RCTs) which convey the next most reliable form of evidence.
Bone Health: A study examining 60 postmenopausal women with osteopenia taking either placebo, 250mg or 500mg of shilajit, found supplementation was able to suppress declines in bone mineral density at 24 and 48 weeks, compared to placebo (p<0.001)(1).
Strength: 63 recreationally trained men (average age 21.2, H: 179.8 and W: 83.1) were randomised to receive placebo, low dose (250mg) or high dose (500mg) shilajit. Researchers found after 8 weeks, subjects taking high dose shilajit became less fatigued and were able to retain a greater level of maximum muscular strength compared to the low dose and placebo groups(2).
Testosterone: 96 males (mean age: ~49) were randomised to placebo or 250mg twice daily of shilajit. Supplementation was able to significantly increase testosterone and free testosterone levels on day 90 (20.45% and 19.14%, respectively) (P<0.05). This was also significantly better than the placebo group (p<0.05)(3). It is worth noting 21 subjects dropped out of this study, the small sample size may not be generalisable.
Recommended serving & duration.
Most studies have examined either low dose 250mg or high dose 500mg per day.
This supplement has very little good quality evidence, therefore I cannot safely recommend its use for any of the above outcomes. Please consult with your healthcare provider before considering this supplement.
Safety & tolerability
Lack of research on safety in both short and long term.
May increase iron levels – studies found in rats. Avoid in conditions such as haemochromatosis(4).
May increase testosterone levels(3, 5).
Important to note there may be variability in the composition of shilajit between different products. Some trials used a patented product “PrimaVie” and these studies were funded by the manufacturer.
References
Pingali U, Nutalapati C. Shilajit extract reduces oxidative stress, inflammation, and bone loss to dose-dependently preserve bone mineral density in postmenopausal women with osteopenia: A randomized, double-blind, placebo-controlled trial. Phytomedicine. 2022;105:154334.
Keller JL, Housh TJ, Hill EC, Smith CM, Schmidt RJ, Johnson GO. The effects of Shilajit supplementation on fatigue-induced decreases in muscular strength and serum hydroxyproline levels. J Int Soc Sports Nutr. 2019;16(1):3.
Pandit S, Biswas S, Jana U, De RK, Mukhopadhyay SC, Biswas TK. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia. 2016;48(5):570-5.
Velmurugan C, Vivek B, Wilson E, Bharathi T, Sundaram T. Evaluation of safety profile of black shilajit after 91 days repeated administration in rats. Asian Pacific Journal of Tropical Biomedicine. 2012;2(3):210-4.
Morgado A, Tsampoukas G, Sokolakis I, Schoentgen N, Urkmez A, Sarikaya S. Do "testosterone boosters" really increase serum total testosterone? A systematic review. Int J Impot Res. 2023.
