Shilajit

What it is

In mountain regions, shilajit seeps out of the rock as a dark brown to black, sticky mass. It consists of humic and fulvic acids, other organic compounds and minerals. There is no clear-cut definition: an assessment for the EU notes that mumijo is clearly defined neither in its origin nor in its composition.

Studies therefore mostly use a purified, standardized extract. The product from the most important testosterone study was standardized to at least 60 % bioactive constituents, of which at least 50 % were fulvic acids. What is sold as resin, powder or capsule does not automatically correspond to this.

How it is supposed to work

In the Ayurvedic tradition, shilajit is considered a rasayana, a remedy for rejuvenation and strengthening, including of male fertility. The modern studies build directly on this and measure hormones, sperm parameters and muscle strength.

The mechanism has barely been studied in humans. In the testosterone study, the pituitary hormone LH remained stable while FSH rose. This points to an effect on the hormonal axis but does not explain it. Also advertised are support for the mitochondria, recycling of coenzyme Q10 and a supply of trace elements. For these claims, no human data could be found in the research for this page. Studies on tissue samples show that after several weeks of intake, certain genes in muscle and skin are read differently, for example genes for connective tissue and small blood vessels.

Tradition and use

Shilajit is not a new scene product. Besides the long Ayurvedic tradition, its use in food supplements in Europe is documented: the Czech Republic reported it for the period before 1997, which is why shilajit in this form is not considered a novel food in the EU. Experience reports from verifiable sources that go beyond this tradition are not available for this page.

What the studies show

Testosterone study 2016: 90 days, placebo-controlled

Pandit and colleagues randomized 96 healthy men aged 45 to 55 to 250 mg shilajit twice daily or placebo. The 75 who completed the 90 days were analyzed. Total testosterone rose by 20.45 % from day 0 and on day 90 was significantly above placebo; in the placebo group it fell slightly. LH remained stable, FSH and DHEAS rose. The study was funded by the manufacturer of the extract.

Strength study 2019: 63 men, 8 weeks

Keller and colleagues gave 21 recreationally active men each 250 mg, 500 mg or placebo. After 8 weeks, 100 maximal leg extensions followed. In the stronger half of participants, strength loss was 8.9 % on 500 mg and 16.0 % on placebo, and a marker of collagen breakdown was lower. The lower dose had no effect. This study, too, was funded by the manufacturer.

Fertility study 2010: without a placebo group

Biswas and colleagues gave 35 men with oligospermia 100 mg of processed shilajit twice daily for 90 days; 28 completed the study. Compared with baseline, total sperm count rose by 61.4 % and testosterone by 23.5 %. Without a comparison group, the contribution of the substance cannot be separated from other influences.

Skin study 2019: 14 weeks in women

Das and colleagues gave healthy middle-aged women 125 mg or 250 mg shilajit or placebo twice daily for 14 weeks. On the higher dose, skin blood flow improved compared with baseline and placebo, and in skin samples genes for new blood vessel formation and connective tissue were more active. No side effects were reported. The study shows that shilajit has measurable tissue effects in humans, but it says nothing yet about noticeable changes in the skin.

Where the data stop

The data base is narrow. The two randomized trials on testosterone and strength were each funded by the manufacturer of the tested extract; no independent replication could be found. The testosterone study analyzed only the men who stayed until the end, 75 of 96. Whether libido, energy or performance change noticeably was not measured as an outcome there. The strength effect appeared only at 500 mg and only in the stronger half of participants. The figure of 23.5 % more testosterone that also circulates comes from the fertility study without a placebo group, not from the controlled trial.

Then there is the product question. The studies used standardized extracts; the market offers very different resins and powders. Another randomized trial on shilajit and resistance training appeared in 2026, but so far only as a preprint without peer review. For the advertised effect on mitochondria and coenzyme Q10, there are no robust figures in humans.

Status, approval and legal

Shilajit is available in Germany as a food supplement. An EU consultation handled by Germany concluded in 2020 that mumijo as or in food supplements is not a novel food, because it was already used this way in the Czech Republic before May 15, 1997. In all other foods it is considered novel and would need its own authorization. For competitive athletes, the general NADA notice on contamination of food supplements applies.

Safety

In the controlled studies, shilajit was well tolerated over 8 to 14 weeks and in the testosterone study over 90 days; liver and kidney values remained unchanged in the fertility study. There are no long-term data. The most important risk is purity: a 2025 laboratory analysis found thallium in raw shilajit and in products, up to 0.5 µg per gram in products and at most 0.095 µg per tablet, in some cases more than in the raw material. For comparison, the authors cite an average dietary intake of under 2 µg per day; other heavy metals have also been described in the literature. There are no data on pregnancy, breastfeeding, children or interactions. Because shilajit changed hormone levels in studies, intake in hormone-dependent conditions should be discussed with a physician.

Sources

• Pandit et al., Andrologia 2016 – shilajit and testosterone, randomized trial
• Keller et al., J Int Soc Sports Nutr 2019 – strength after fatigue
• Biswas et al., Andrologia 2010 – sperm parameters in oligospermia
• Das et al., J Med Food 2016 – gene expression in muscle
• Das et al., J Am Coll Nutr 2019 – skin and microcirculation
• Kamgar et al., BMC Chem 2025 – thallium in shilajit and products
• EU consultation on the novel food status of mumijo, 2020
• NADA 2014 – guidance on handling food supplements