Supplement: Shilajit

A 2024 systematic review of testosterone boosters concluded that most marketed products do nothing. It counted purified shilajit among the few it judged possibly effective for men with low testosterone.

Shilajit is a blackish-brown, tar-like resin that seeps from cracks in Himalayan rock, used for centuries in Ayurvedic medicine as a rasayana. The single trial behind that testosterone verdict followed middle-aged men for 90 days, the best human data available.

People take shilajit today mostly for testosterone, energy, and fertility, the three areas the thin human evidence covers. The resin forms slowly, as decomposed plant and microbial matter is compressed inside high-mountain stone.

What's Inside the Resin

The same three families of compounds behind shilajit's proposed effects also carry its main risk. Amino acids and other trace constituents make up the remainder.

Anatomy of the Practice

1Fulvic acid and humic substances

More than 80% of shilajit by weight is humic substances, and fulvic acid is the fraction most studied. Fulvic acid is a small, water-soluble antioxidant molecule that binds minerals and helps move them across cell membranes. It is the compound behind most of the proposed effects, from mineral transport to the laboratory work on brain-protein aggregation.

2Minerals and trace elements

About a fifth of shilajit is minerals, dominated by calcium, potassium, and magnesium, plus trace elements. The same material that carries useful minerals can also carry lead, arsenic, mercury, and cadmium. How much depends on the source rock and processing.

3Dibenzo-alpha-pyrones

Shilajit contains a characteristic class of compounds called dibenzo-alpha-pyrones, often standardized for in supplement extracts. In animal studies, these and the fulvic acids act on mitochondria. Researchers propose this as the mechanism behind the anti-fatigue effect seen in rats.

What the Research Found

The strongest finding, on testosterone, rests on that single trial. Pandit and colleagues, in 2016, randomized healthy men aged 45 to 55 to 250 mg of purified shilajit twice a day, or placebo, for 90 days. Total testosterone, free testosterone, and DHEAS rose in the treated group. The trial was small and industry-linked, reported no absolute hormone values, and enrolled only men.

The next-strongest evidence is for fertility, and it rests on one small uncontrolled study. Biswas and colleagues, in 2010, gave 35 men with low sperm counts 100 mg of processed shilajit twice a day for 90 days. Of the 28 who finished, sperm count, motility, and testosterone rose, and oxidative stress in semen fell. There was no placebo group, so the result stays preliminary. Animal work backs a profertility effect, including protection against a toxic-metal challenge in male mice.

Energy has been tested mainly in animals. In one rat model of chronic fatigue, a standardized shilajit extract reduced fatigue-like behavior. No controlled human trial has shown the same, so the energy claim is still early.

Across the human trials, the reported effects are modest, measured over about three months.

How It Works

The proposed mechanism centers on two components: fulvic acid and the dibenzo-alpha-pyrones. Both act as antioxidants and appear to support mitochondria. In the rat fatigue model, a standardized extract protected mitochondrial enzyme activity and steadied the stress-hormone axis. The researchers proposed that as how it reduced fatigue.

The 2016 trial that measured testosterone did not identify how it rose. Testosterone climbed while LH and FSH, the pituitary signals that normally drive it, stayed in normal range.

A separate line of laboratory research looks at the brain. In test tubes, fulvic acid interferes with the clumping of tau, one of the proteins tied to Alzheimer's disease. That work is in cell and animal models; it has not been shown in humans.

How Strong the Evidence Is

Three limits shape how much weight the human evidence carries:

• The human studies are few, and most are small.
• Several test one proprietary purified extract.
• Some are connected to the company that makes that extract.

The Research & Studies

Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.

Progress Markers

Raised testosterone in men aged 45 to 55 in one 90-day trialEmerging

In plain terms

In one three-month trial, healthy middle-aged men who took a purified shilajit extract had higher testosterone than men on a placebo, and a later review counted it among the few supplements that may nudge testosterone in men.

In detail

Pandit 2016 randomized healthy men aged 45 to 55 to purified shilajit 250 mg twice daily or placebo for 90 days and reported significant rises in total testosterone, free testosterone and DHEAS (P<0.05), with gonadotropins LH and FSH maintained. The abstract gives no absolute hormone values, so the size of the change in everyday terms cannot be read from it, and it is a single small study from one Ayurvedic research group using one proprietary purified extract. Morgado 2024 systematically reviewed 52 studies of 27 proposed testosterone boosters and found most did not raise total testosterone; purified shilajit extract was one of a handful considered possibly effective in men with late-onset hypogonadism.

Who this may not transfer to:Measured only in men, and the outcome is male androgen levels, so it says nothing about effects in women, in whom testosterone physiology is different.

The studies · 2

Pandit 2016, Andrologia · Andrologia

Morgado 2024, Int J Impot Res · Int J Impot Res

Fertility

Raised total sperm count 61.4% in men with low countsPreliminary

In plain terms

In a small study of men with low sperm counts, three months of processed shilajit raised sperm count and improved motility, and lowered a marker of oxidative stress in semen.

In detail

Biswas 2010 enrolled 35 oligospermic men (baseline count below 20 million/ml) on processed shilajit 100 mg twice daily for 90 days; the 28 who finished showed significant gains in spermia (+37.6%), total sperm count (+61.4%), motility (+12.4 to 17.4%) and normal forms (+18.9%), with serum testosterone up 23.5% and FSH up 9.4% (both significant), and semen malondialdehyde down 18.7%. Unchanged hepatic and renal profiles indicated the dose was tolerated. There was no placebo arm, so part of the gain over 90 days could run through expectation and natural variation, and expectation is itself a documented contributor to how the body responds.

Who this may not transfer to:Studied only in men with low sperm counts, so it does not speak to female fertility or to men whose counts are already normal.

The study · 1

Biswas 2010, Andrologia · Andrologia

Raised sperm production in rodent studiesPreliminary

In plain terms

In rodent studies, shilajit boosted sperm production and protected fertility against a toxic-metal challenge.

In detail

Park 2006 reported that chronically administered shilajit had both spermatogenic and ovogenic effects in rats, acting on male and female reproductive tissue. Mishra 2018 found shilajit reduced cadmium-induced infertility in male mice. Together these give animal support for the traditional profertility use, but animal reproductive findings do not establish an effect in people.

The studies · 2

Park 2006, J Ethnopharmacol · J Ethnopharmacol

Mishra 2018, Andrologia · Andrologia

Energy And Fatigue

Eased fatigue-like behavior in chronically stressed ratsPreliminary

In plain terms

In rats made chronically fatigued, shilajit lowered fatigue-like and anxious behavior and steadied their stress-hormone response.

In detail

Surapaneni 2012 induced chronic-fatigue-like behavior in rats by 21 days of forced swimming and pre-treated them with shilajit at 25, 50 or 100 mg/kg. Shilajit reversed the increase in immobility and the decrease in climbing, reduced anxiety on the elevated-plus-maze, and normalized plasma corticosterone and adrenal weight, which the authors read as modulation of the hypothalamic-pituitary-adrenal axis. The extract was standardized to 56.75% fulvic acids, 20.45% dibenzo-alpha-pyrone chromoproteins and 0.43% dibenzo-alpha-pyrones.

The study · 1

Surapaneni 2012, J Ethnopharmacol · J Ethnopharmacol

Counts once: this finding and 1 other here come from the same source, so they are one body of evidence, not separate confirmations.

How it works

Protected mitochondrial enzymes in stressed rats, a proposed mechanismPreliminary · mixed

In plain terms

In rats, shilajit helped protect mitochondria, the tiny structures inside cells that produce energy, from stress-related damage, which the researchers proposed as how it eased fatigue.

In detail

In Surapaneni 2012, chronic swim stress lowered the activity of mitochondrial respiratory-chain enzymes (Complexes I, II, IV and V) and mitochondrial membrane potential in the prefrontal cortex, and raised oxidative-stress markers. Shilajit pre-treatment stabilized the complex enzyme activities and membrane potential and reversed the oxidative-stress markers (nitric oxide, lipid peroxidation, superoxide dismutase and catalase), leading the authors to name mitochondria as a potential target. This is a proposed mechanism from a single animal study.

The study · 1

Surapaneni 2012, J Ethnopharmacol · J Ethnopharmacol

Counts once: this finding and 1 other here come from the same source, so they are one body of evidence, not separate confirmations.

More than 80% humic substances plus about 20% mineralsPreliminary · mixed

In plain terms

Shilajit is mostly humic substances such as fulvic acid, plus minerals, and its exact makeup has never been fully pinned down and varies a lot depending on where it comes from.

In detail

Kamgar 2025 reviewed the analytical literature and reports that more than 80% of shilajit by weight is humic substances (fulvic acid the most-studied active fraction), about 20% is minerals dominated by calcium, potassium and magnesium, and the remainder includes amino acids (mainly glycine) and proteins, fatty acids, bioactive acids such as caffeic and gallic acid, dibenzo-alpha-pyrones, and trace metals including chromium, selenium and cobalt. The review stresses that no comprehensive chemical analysis has fully characterized shilajit and that composition differs markedly between source regions.

The study · 1

Kamgar 2025, Crit Rev Anal Chem · Crit Rev Anal Chem

Ayurveda used shilajit as a rasayana for over a thousand years, purified firstPreliminary · mixed

In plain terms

Shilajit has been used as a rejuvenating tonic in Ayurveda for well over a thousand years, and the tradition never took the raw rock resin as found: it purified it first (a step called Shodhana) to remove impurities. Modern chemistry points to fulvic acid and a class of compounds called dibenzo-alpha-pyrones as its main active parts.

In detail

Wilson 2011 reviewed shilajit in traditional Indian and Siddha medicine, where classical texts and pharmacopoeias describe it as a rasayana or rejuvenator taken to prevent ailment and enhance quality of life; the Charaka Samhita is among the texts that record its long use. Classical Ayurveda specifies purification (Shodhana) of raw resin by washing and processing in herbal decoctions such as Triphala kwath before it is considered fit to take, which is the tradition's own control on the mineral and metal load that raw resin can carry. Stohs 2014, reviewing safety and efficacy, identifies dibenzo-alpha-pyrones and fulvic acid and their derivatives as the constituents most responsible for the reported effects, and notes that purified shilajit has a well-documented safety record in animal and human studies while relatively few well-controlled human trials have yet been run. Fulvic acid, a small water-soluble molecule, binds minerals and helps carry them across cell membranes, which is the mineral-carrier role the tradition intuited before the chemistry was described.

The studies · 2

Wilson et al., review on shilajit used in traditional Indian medicine · J Ethnopharmacol 2011;136(1):1-9

Stohs, safety and efficacy of shilajit (mumie, moomiyo) · Phytother Res 2014;28(4):475-9

Cognition

Fulvic acid slowed Alzheimer-linked tau clumping in a dish, no human trial yetPreliminary · mixed

In plain terms

In lab-dish experiments, fulvic acid from shilajit stopped a protein tied to Alzheimer's from clumping, which has led researchers to propose it as a possible brain-protective compound.

In detail

Cornejo 2011 showed in cell-free experiments that fulvic acid inhibits the assembly of tau protein into paired helical filaments and can disassemble preformed filaments, shortening fibril length and altering their structure. Carrasco-Gallardo 2012 reviewed this and related work and proposed shilajit and fulvic acid as candidate procognitive nutraceuticals, while calling for basic studies and clinical trials. All of this is test-tube and review-level evidence about a mechanism; no controlled human trial has shown shilajit improves memory or slows cognitive decline.

The studies · 2

Cornejo 2011, J Alzheimers Dis · J Alzheimers Dis

Carrasco-Gallardo 2012, Int J Alzheimers Dis · Int J Alzheimers Dis

Purity Is the Real Question

Because shilajit is scraped from rock, its safety depends on what else was in that rock. Elemental analysis of commercial Indian and Pakistani products has found lead, arsenic, mercury, and other metals above permissible limits. A broader review reported that shilajit can contain around 65 metals. Most products tested came in under safety limits, but some exceeded them. The authors concluded that taking it without knowing its metal content is not safe.

Classical Ayurveda never used raw resin. Practitioners first ran it through one preparatory step, Shodhana, a purification in herbal decoctions such as Triphala that strips much of the mineral and metal load. The humic and fulvic acids in shilajit can also bind some metals on their own. Neither the ancient step nor that natural binding makes an untested modern product safe. A natural origin does not make a product low in heavy metals; only a batch test shows that.

Only purified shilajit with independent heavy-metal testing is appropriate to take; a product that cannot show a certificate of analysis for its batch cannot be verified as clean.

How to Use It

Ways to Do It

If shilajit fits your goals, and any clinician guiding your care agrees, purity comes before dose.

1

Use purified product only, not raw resin$$Easy

Only purified shilajit is appropriate to take. Raw or unprocessed resin scraped from rock can carry heavy metals, mycotoxins, and free radicals, and purification removes much of that load. Purified extracts, often standardized to fulvic acid or dibenzo-alpha-pyrones, are the form used in the human studies. Raw or wild-harvested resin sold with no processing described has not been through that step.

2

Choose a product with third-party heavy-metal testing$$Moderate

Contamination depends on the source rock and cannot be judged by eye. The one check that matters is an independent laboratory test for lead, arsenic, mercury, and cadmium, ideally with a certificate of analysis for the specific batch. If a product will not show its heavy-metal results, its safety cannot be verified. This check matters more than the dose.

3

Match the dose to what was studied$$Easy

The testosterone trial used purified shilajit at 250 mg twice daily. The sperm study used processed shilajit at 100 mg twice daily. Both ran for 90 days, and those are the doses and durations the evidence covers. Doses above the studied 100 to 250 mg twice daily add risk without added benefit.

4

Set realistic expectations and give it the studied window$Easy

Judge shilajit by how you feel across the full three months, and give it that window before deciding. It is one input among many, and it works best paired with practices that have stronger evidence for the same goals, such as resistance training for testosterone and muscle.

Go Deeper

Shilajit works best next to practices with stronger human evidence for the same goals. For testosterone and muscle, resistance training is the higher-evidence, no-cost lever, and ashwagandha is the other herb men reach for. For the aging process behind these goals, see biological aging. Because shilajit is a mineral-bearing substance, clean water and remineralization covers minerals from a better-characterized source. If steady energy is your aim, the better-evidenced practices carry more of the load.

The Ayurvedic Tradition

The Charaka Samhita, a founding text of Ayurveda, describes shilajit as a rasayana taken over time to build strength and slow the wearing of age. It claims that, used properly, shilajit can help almost any treatable illness. One placebo-controlled trial and a long tradition of use justify interest, not a proven result. Its best-known traditional uses are vitality and the reproductive and urinary system, and Himalayan cultures relied on it continuously for well over a thousand years.

A Chinese Medicine Bridge

No historical Chinese text describes shilajit. Chinese medicine still works extensively with mineral and earth-derived substances, and its tonifying herbs, the bu herbs, replenish the body's reserves. The warming Kidney and Yang tonics are what a practitioner reaches for in someone depleted, cold, and low in drive. In that tradition the Kidney governs Jing, the deep constitutional essence tied to reproduction, growth, and aging. Some modern Western practitioners place shilajit beside these Kidney-Yang and Jing tonics by analogy. This pairing is a modern Western analogy, not a classical Chinese teaching. Shilajit's evidence rests on the Ayurvedic tradition and the modern studies.

Cautions

Shilajit carries five cautions, and the heavy-metal risk is the largest.

Cautions For This Practice

Extra restraint

Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.

Can contain around 65 metals, including toxic lead, arsenic and mercury

Hussain 2024 searched the scientific literature and traditional sources and reports shilajit can contain around 65 metals, among them the toxic heavy metals copper, aluminum, lead, arsenic, cadmium and mercury. Reported levels were generally below the WHO and FDA permissible limits for herbal drugs, but some studies found the limits exceeded. The review notes that humic substances in shilajit can chelate around a dozen metals, which is a proposed protective effect, but concludes the detoxification data are not yet clarified and that consuming shilajit without knowing its metal content is not safe.Hussain 2024, Biol Trace Elem Res

Retail shilajit tested with lead, arsenic and mercury above safe limits

Aldakheel 2022 analyzed two widely sold shilajit products (one Indian, one Pakistani) using laser-induced breakdown spectroscopy, inductively coupled plasma spectrometry and energy-dispersive X-ray spectroscopy. Both were rich in the nutrients calcium, sulfur and potassium but also carried aluminum, strontium, manganese, barium, zinc, nickel, boron, chromium, lead, arsenic and mercury above standard permissible limits, with toxins generally higher in the Indian sample and mercury and titanium detected only there. The authors framed the work as safety awareness for consumers.Aldakheel 2022, Biol Trace Elem Res

Use only purified, tested product; raw resin can carry heavy metals

Raw or unpurified shilajit can carry toxic heavy metals such as lead, arsenic, mercury, and cadmium, along with mycotoxins and free radicals. Testing of commercial products has found metals above permissible limits. Purification plus an independent batch test for those metals separates a usable product from an unverified one. Without a certificate of analysis, cleanliness cannot be confirmed.

Do not take it in pregnancy or while breastfeeding

Shilajit is not recommended during pregnancy or breastfeeding. Safety data is insufficient for both. The heavy-metal risk is of particular concern for a developing baby, since lead and mercury cross the placenta and pass into breast milk. The cautious course is to avoid it during pregnancy, while trying to conceive, and while breastfeeding.

Iron overload and hemochromatosis

Shilajit contains iron and other minerals and has been used traditionally to support iron levels. That is a reason for care if you have hereditary hemochromatosis or another iron-overload condition, where added iron can accumulate and cause harm. If you have an iron-overload disorder, treat shilajit as something to discuss with the doctor who oversees that condition before adding it.

Medications and existing conditions

Shilajit can affect testosterone, iron levels, and blood sugar. If you take hormone therapy, iron supplements, or diabetes medication, raise it with your clinician first. Anyone with active gout should also be cautious, as shilajit has been reported to raise uric acid. If you take regular medication or manage a chronic condition, treat starting shilajit as a decision to make with a professional.

Quality and source vary widely

The composition of shilajit differs markedly between regions and products, and no product is fully characterized, so what is in one jar is not necessarily what is in another. A trustworthy supply states its origin and processing and publishes batch heavy-metal testing; without that, purity cannot be confirmed.

Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.

Common Questions

Does shilajit actually raise testosterone?

In one trial, yes, and by a modest amount. Pandit's 2016 study gave middle-aged men purified shilajit at 250 mg twice daily for three months and measured rises in total and free testosterone, plus DHEAS. It was a single, small, industry-linked trial that listed no absolute hormone values, so the effect size and durability are not established.

Is shilajit safe, and what is the heavy-metal risk?

The safety question is about contamination from the source rock. Because it is drawn from rock, shilajit can carry toxic metals like lead, arsenic, mercury, and cadmium. One review found shilajit may hold roughly 65 metals in all, most tested products under safety limits but some above. Only a purified product with published third-party testing for heavy metals can be judged safe.

Does shilajit help with fatigue and energy?

The energy evidence is mostly from animals so far. A rat study of chronic fatigue found that a standardized extract cut fatigue-like behavior and protected mitochondrial function. That points to a plausible mechanism, but no controlled human trial has confirmed it, so treat the energy benefit as preliminary.

Can it improve fertility or sperm count?

The human evidence is a single uncontrolled study. Biswas 2010 treated 35 men who had low sperm counts. The 28 who completed it showed higher sperm count, better motility, higher testosterone, and less oxidative stress in semen. With no placebo group, some of the gain could come from expectation or natural variation over the three months. Animal studies also support a fertility benefit. The traditional use is worth taking seriously, though the evidence does not yet establish shilajit as a treatment for infertility.

How much do people take, and what should I look for in a product?

Studies used 100 to 250 mg of purified or processed shilajit, taken twice daily for roughly 90 days, so that is the range the evidence covers. What matters more than the dose is the product. Choose purified shilajit that names its source and processing method and provides a batch-specific certificate of analysis.