Shilajit is a tar-like resin found in mountain rocks, used for centuries in traditional medicine and now gaining popularity as a supplement for men’s health. Its active compounds, primarily fulvic acid, appear to support testosterone levels, fertility, muscle recovery, and cellular energy production. The research base is still small, with only about 15 clinical trials meeting quality standards as of 2024, but the early results point in a consistent direction.
Fertility and Sperm Health
The strongest human evidence for shilajit in men comes from fertility research. In a clinical study of men with low sperm counts who took processed shilajit for 90 days, total sperm count increased by 61.4%, the number of normally shaped sperm rose by 18.9%, and overall semen volume improved by 37.6%. Sperm motility, the ability of sperm to swim effectively, also improved by 12 to 17% depending on the time point measured. These are meaningful changes for men dealing with subfertility.
The study also found decreases in pus cells and epithelial cells in semen samples, which suggests a reduction in inflammation or low-grade infection in the reproductive tract. For men who have been told they have oligospermia (a clinical term for low sperm count), these numbers offer a reason to consider shilajit alongside conventional fertility support.
Testosterone and Hormonal Effects
Shilajit has been marketed aggressively as a testosterone booster, and there is some basis for the claim, though the picture is more nuanced than supplement ads suggest. Clinical trials have observed increases in both testosterone and follicle-stimulating hormone (a hormone involved in sperm production) in men taking shilajit. However, experts caution that many “testosterone booster” products carry exaggerated marketing claims that outpace the clinical evidence.
Because shilajit does appear to influence hormone levels, men with hormone-sensitive conditions should be cautious. If you have a condition that could be worsened by rising testosterone or shifts in reproductive hormones, this is worth discussing with a provider before supplementing.
Muscle Strength and Exercise Recovery
A well-designed study in the Journal of the International Society of Sports Nutrition tested shilajit in 63 recreationally active men over eight weeks. The men were split into three groups: 500 mg per day, 250 mg per day, or placebo. After the supplementation period, researchers fatigued their muscles and measured how much strength they lost.
The results favored the higher dose. Men taking 500 mg daily lost only about 9% of their maximum strength after the fatiguing protocol, compared to roughly 16% in the placebo group. The lower dose of 250 mg showed no meaningful difference from placebo, which suggests there’s a threshold you need to reach for this benefit.
The same study tracked a marker of collagen breakdown in the blood called hydroxyproline. Among the men with the highest baseline levels of this marker, those on 500 mg daily saw a 29% decrease, while the low-dose and placebo groups stayed the same. Collagen is a key structural protein in tendons, ligaments, and the connective tissue surrounding muscles. A drop in its breakdown marker suggests shilajit may help protect connective tissue during periods of hard training. For men who lift weights or do high-volume exercise, this combination of better strength retention and lower connective tissue stress is notable.
Energy and Fatigue Reduction
One of the most commonly reported reasons men take shilajit is for energy, and animal research offers a plausible explanation for why it might work. In a chronic fatigue model, shilajit preserved the function of mitochondria, the structures inside cells that produce energy. Specifically, it stabilized the enzyme systems that drive energy production and protected mitochondria from oxidative damage.
Shilajit also appeared to normalize the stress-hormone system (the loop between the brain and adrenal glands that governs cortisol-like hormones), which becomes dysregulated during prolonged fatigue. Animals treated with shilajit showed reversed behavioral symptoms of chronic fatigue alongside these cellular improvements. While animal studies don’t automatically translate to humans, the mechanism is consistent with what traditional practitioners have claimed for centuries: that shilajit acts as a rejuvenator and energy restorer.
Cognitive Protection
Fulvic acid, the primary active component in shilajit, has shown interesting effects on brain health in laboratory research. It inhibits the clumping of tau protein, one of the hallmark features of Alzheimer’s disease. More striking, fulvic acid was able to break apart tau fibrils that had already formed, reducing their length and disrupting their structure. This happened at the molecular level by interfering with the way these proteins stick together through water-repelling interactions.
This is preclinical work, not proof that shilajit prevents dementia in humans. But it does suggest that regular intake of fulvic acid could have neuroprotective properties worth studying further, particularly for men concerned about long-term cognitive decline.
How It Enhances Nutrient Absorption
Fulvic acid does something beyond its own direct effects: it helps your body absorb other nutrients more efficiently. It naturally binds to minerals and trace elements, acting as a carrier molecule that improves their uptake in the gut. Research has shown that fulvic acid increases absorption of copper in cell models while simultaneously reducing its toxicity, a combination that’s hard to achieve with mineral supplements alone. It has also been shown to improve the bioavailability of certain medications by enhancing absorption across intestinal tissue.
This carrier effect is one reason shilajit is sometimes recommended alongside other supplements. If you’re already taking a mineral complex or multivitamin, shilajit may help you get more out of it.
Dosage Used in Studies
Clinical trials have used doses ranging from 200 mg to 2,000 mg daily, but 500 mg per day is the most common regimen, typically split into two doses of 250 mg. The muscle study described above found clear benefits at 500 mg but not at 250 mg, which reinforces that 500 mg daily is a reasonable starting point. Optimal doses for specific outcomes haven’t been established yet, so this figure represents the best current estimate rather than a definitive recommendation.
Shilajit is available as resin, powder, and capsules. Purified or processed forms are important because raw shilajit can contain heavy metals, fungal contamination, or other impurities. Look for products that specify purification and third-party testing.
Safety Considerations
Across the clinical trials reviewed through 2024, shilajit has generally been well tolerated at standard doses. That said, a few groups should exercise caution. Because shilajit raises testosterone and other reproductive hormones, men with hormone-sensitive conditions (such as certain prostate issues) should be careful. Its mineral content and absorption-enhancing properties could theoretically be problematic for men with iron overload conditions. Pregnant and breastfeeding individuals are also advised to avoid it due to lack of safety data.
If you take prescription medications, the same fulvic acid that boosts nutrient absorption could also alter how your body processes drugs. This is especially relevant for medications with narrow dosing windows where small changes in blood levels matter.