Among shilajit’s proposed benefits, testosterone support has some of the strongest human clinical evidence. Two well-designed randomised controlled trials have examined this relationship in male subjects, both reporting statistically significant improvements in testosterone markers. This page reviews those studies in detail, explains what is known about the mechanisms involved, and provides a realistic assessment of what the evidence means for people considering shilajit supplementation.
For the full research overview, see our shilajit research page. For our tested product, see our Himalayan Shilajit Resin page. For quality documentation, see our research and testing page.
Why Testosterone Matters and Who Is Affected
Testosterone is the primary androgen in men, produced mainly in the Leydig cells of the testes in response to luteinising hormone (LH) from the pituitary gland. It plays central roles in muscle mass and strength, bone density, red blood cell production, sperm production, libido, mood, energy levels, and cognitive function. After approximately age 30, total testosterone in men declines at a rate of roughly 1–2% per year on average, with free testosterone declining faster due to age-related increases in sex hormone-binding globulin (SHBG). This age-related decline is associated with reduced muscle mass, increased body fat, fatigue, reduced libido, and mood changes in a significant proportion of men over 40.
Natural interventions that support testosterone within the normal physiological range — without the risks associated with testosterone replacement therapy — are of significant interest to ageing male populations.
Study 1: Pandit et al., 2016 — Testosterone in Healthy Ageing Men
Study Design
This double-blind, randomised, placebo-controlled clinical trial is the most rigorous testosterone study currently published for shilajit. It was conducted by Pandit, Biswas, Jana, De, and Mukhopadhyay, and published in the journal Andrologia in 2016. The study enrolled 75 healthy male volunteers aged 45–55 years — an age group specifically selected because testosterone decline is measurable and practically relevant in this demographic. Participants were randomised to receive either 250 mg of processed shilajit twice daily (500 mg/day total) or a matched placebo for 90 days. The study was conducted in India and used processed shilajit with documented quality parameters.
Primary Outcomes
Serum testosterone was measured by radioimmunoassay at baseline, at 45 days, and at 90 days. The results after 90 days showed:
- Total testosterone: 20.45% increase from baseline in the shilajit group versus no significant change in placebo (statistically significant; p < 0.05)
- Free testosterone: 19.17% increase in the shilajit group versus no significant change in placebo (statistically significant; p < 0.05)
- DHEA (Dehydroepiandrosterone): 31.4% increase in the shilajit group versus marginal non-significant change in placebo
Safety Outcomes
Importantly, the study monitored a comprehensive safety panel including liver function enzymes (ALT, AST, ALP), kidney function (serum creatinine, BUN), full blood count, and lipid profile at each measurement point. None of the safety markers showed clinically significant changes in either group. The study explicitly concluded that 500 mg/day of processed shilajit was safe and well-tolerated over 90 days in the study population.
Study Limitations
Sample size (75 participants, approximately 38 per group) is modest by pharmaceutical trial standards. The study duration was 90 days — adequate for a testosterone intervention study but not sufficient to determine long-term effects. The study was conducted in a specific demographic (healthy Indian men aged 45–55) and generalisability to other populations (younger men, men with hypogonadism, men of different ethnicities) has not been established by direct research.
Study 2: Biswas et al., 2010 — Testosterone and Sperm Quality in Infertile Men
Study Design
Published in Andrologia in 2010, this study by Biswas, Thakur, Mandal, and Paul enrolled 60 infertile men diagnosed with oligospermia (sperm count below 20 million/mL). Participants were randomised to receive either 100 mg of processed shilajit twice daily (200 mg/day — a notably lower dose than the Pandit study) or placebo for 90 days. The primary outcomes were sperm quality parameters, with testosterone measured as a secondary outcome.
Key Results
- Total sperm count: +61.4% in shilajit group (statistically significant)
- Sperm motility (total): +12.4–17.4% improvement across different motility categories (statistically significant)
- Normal sperm morphology: +18.9% (statistically significant)
- Serum testosterone: Statistically significant increase in the shilajit group versus placebo
The improvements in sperm parameters are directly clinically relevant to the study population (infertile men with oligospermia). The testosterone increase reinforces the findings of the Pandit study and suggests the effect is robust across different populations and dose levels.
Significance at a Low Dose
A notable feature of this study is its positive findings at 200 mg/day — well below the 500 mg/day used in the Pandit study. This suggests that testosterone and reproductive effects may be achievable at lower doses than typically discussed in general wellness contexts, though the population studied (infertile men, who may respond differently from healthy men) limits direct comparison.
Proposed Mechanisms: Why Does Shilajit Affect Testosterone?
The mechanisms through which shilajit influences testosterone are not yet fully elucidated. Several plausible pathways have been proposed based on its known chemistry:
Gonadotropin Stimulation
LH (luteinising hormone) from the pituitary stimulates Leydig cells in the testes to produce testosterone. Some research has suggested that certain compounds in shilajit may interact with the hypothalamic-pituitary-gonadal (HPG) axis to support LH signalling, thereby stimulating endogenous testosterone production. Direct evidence for this mechanism in humans is limited but is consistent with the observed increase in free testosterone (which would be expected if LH stimulation were driving the effect).
Mineral Availability for Steroidogenesis
Testosterone synthesis (steroidogenesis) requires multiple enzymatic steps, many of which have trace mineral co-factor requirements. Zinc is particularly important — it is required for the function of 3β-hydroxysteroid dehydrogenase, an enzyme in the testosterone synthesis pathway. Selenium is required for antioxidant protection of Leydig cells. Magnesium is involved in downstream hormone signalling. Shilajit’s supply of these minerals in ionic, bioavailable form may support the enzymatic capacity for testosterone synthesis, particularly in individuals with marginal mineral status.
Mitochondrial Energy Support in Leydig Cells
Steroidogenesis is an energetically demanding process — testosterone synthesis requires ATP at multiple steps. The DBP compounds in shilajit that support mitochondrial electron transport chain activity may enhance ATP availability in Leydig cells, supporting the energy demands of testosterone synthesis. This mitochondrial mechanism would also explain why shilajit’s testosterone effects appear gradually over weeks rather than acutely.
Antioxidant Protection of Testicular Tissue
Leydig cells are particularly vulnerable to oxidative stress, which has been shown to impair testosterone synthesis. Fulvic acid’s antioxidant activity may protect testicular tissue from oxidative damage, maintaining the functional capacity of Leydig cells. This mechanism is supported by animal studies showing that antioxidant supplementation can support testosterone levels in models of oxidative stress-induced hypogonadism.
What the Evidence Realistically Means
Both human trials show statistically significant testosterone increases in male populations. The effect sizes are meaningful — 20% increases in total and free testosterone represent clinically relevant changes. The effects appear at both low (200 mg/day) and standard (500 mg/day) doses. Safety profiles in both studies were excellent.
Important caveats: these studies involved specific populations (infertile men and healthy ageing men in India). They did not include younger healthy men with normal testosterone levels. They ran for 90 days — not sufficient for long-term conclusions. And they used processed shilajit with quality parameters — not all shilajit products on the market match the research preparations. Replicating these results requires using a product of comparable quality: purified, with documented fulvic acid content, from a verified Himalayan source.
To explore our tested product, visit our Himalayan Shilajit Resin page. For full quality documentation, see our research and testing page.
References
- Pandit S et al. (2016). Clinical evaluation of purified shilajit on testosterone levels in healthy volunteers. Andrologia, 48(5), 570–575.
- Biswas TK et al. (2010). Clinical evaluation of spermatogenic activity of the root of Ashwagandha and shilajit in oligozoospermic males. Andrologia, 42(1), 48–56.
- Agarwal SP et al. (2007). Shilajit: A review. Phytotherapy Research, 21(5), 401–405.
- Ghosal S (1990). Chemistry of Shilajit. Pure and Applied Chemistry, 62(7), 1285–1288.
