What it's actually good for
Shilajit is a tar-like resin that seeps from rock in the Himalayas and a few other mountain ranges, formed over centuries from compressed plant matter and minerals. Traditional Ayurvedic medicine has used it as a general tonic for millennia, and the modern supplement market has picked it up as a "natural testosterone booster" and recovery aid. That marketing is ahead of the evidence, but — unusually for this category — the evidence isn't nothing. There is one real, well-designed human RCT behind the testosterone claim, and one behind the muscle-recovery claim. The honest read is: legitimate early signal, badly under-replicated, sitting inside a supplement category with a genuine and well-documented safety problem.
What the research says
Testosterone (Grade C — real trial, single trial). Pandit et al. (2016, Andrologia) randomized 96 healthy men aged 45-55 to purified shilajit (250 mg twice daily) or placebo for 90 days. Total testosterone, free testosterone, and DHEAS all rose significantly versus placebo, with luteinizing hormone and follicle-stimulating hormone unchanged — a pattern consistent with a real physiological effect rather than a lab artifact. But it's one trial. No independent group has replicated it, the men studied were healthy rather than clinically low in testosterone, and a single 90-day study in fewer than 100 people isn't enough to call this settled, whatever the effect size looked like.
Muscular strength and recovery (Grade C). Keller et al. (2019, JISSN) randomized 63 recreationally active men to placebo, 250 mg/day, or 500 mg/day of the same purified extract for 8 weeks, then measured strength loss after a fatiguing exercise protocol. In the subgroup with higher baseline strength, the 500 mg group lost significantly less strength (8.9% vs. 16-17% for placebo and the low dose) and showed a smaller post-exercise rise in serum hydroxyproline, a marker of connective-tissue breakdown. The effect only reached significance in these subgroup analyses, not across the whole sample — a real finding, but a narrower one than "shilajit improves recovery" implies.
How much, and which form
Both trials used purified, standardized extract (PrimaVie, standardized for fulvic acid content) at 250-500 mg/day, split into two doses. That's the form and dose range with actual trial data behind it. Raw shilajit resin sold as a scoop-able tar or chewable chunk has essentially none of this evidence — it's a different, unstandardized product, and it's where the contamination risk concentrates.
Safety
This is the section that matters most for shilajit. The purified extract used in both trials was well tolerated over 90 days with no serious adverse events reported. But shilajit forms geologically and absorbs heavy metals from the surrounding rock, and this isn't a theoretical concern: a 2024 review found roughly 65 detectable heavy metals across tested shilajit samples, with most falling under WHO/FDA limits but some exceeding them. A 2025 lab analysis went further, finding thallium — a metal toxic even in small, chronic doses — in both crude shilajit and commercial supplements, with some finished supplements containing more thallium than the raw material they were made from. That means purification and manufacturing quality, not just sourcing, determine whether a given bottle is safe. Buy only from brands that publish batch-specific, third-party heavy-metal testing. This is informational, not medical advice — talk to a clinician before starting, particularly if you have an iron-overload condition or are on hormone therapy.
How we picked the brand
A shilajit product earns a spot here only if it uses a purified, standardized extract (not raw resin), publishes third-party heavy-metal testing with a batch-specific Certificate of Analysis, and — ideally — is the same standardized extract used in the clinical trials, so the dose on the label maps to a dose that's actually been studied.