- No topic reaches “moderate” or “strong” on our scale. The best-supported areas rest on one or two small human trials each.
- Most published human trials used one branded, standardised extract. Results may not carry over to resin, powder or gummies from other suppliers.
- Several popular claims, including sleep, kidney health and stress, have no controlled human research behind them that we are aware of.
How to read the ratings
Each topic gets a rating for the type and amount of evidence, not for how impressive a single result looks. A dramatic finding in rats still sits below a modest finding in a controlled human trial. The approach borrows from formal evidence-grading systems such as GRADE, which judge the certainty of a body of evidence rather than individual headlines.[1]
The full method, including how we handle funding and study quality, is on our evidence rating system and how we grade evidence.
All topics at a glance
| Topic | Rating | Best evidence available |
|---|---|---|
| Testosterone | Limited | One randomised trial in healthy men |
| Male fertility | Very limited | One uncontrolled study |
| Libido & sexual function | Limited | One randomised trial, in women |
| Energy & fatigue | Very limited | Indirect data from an exercise trial |
| Exercise & muscle | Limited | One randomised trial; one gene-expression study |
| Cognition & memory | Preclinical only | Laboratory and animal work |
| Sleep | Not studied | None found |
| Stress & mood | Preclinical only | Animal studies |
| Inflammation & joints | Very limited | Secondary markers in one trial |
| Bone health | Limited | One randomised trial in postmenopausal women |
| Metabolic health | Preclinical only | Mainly animal studies |
| Immune function | Preclinical only | Animal and laboratory work |
| Kidney & urinary | Not studied | Traditional use only |
| Skin & hair | Very limited | Skin biomarkers in one trial; nothing on hair |
| Women’s health | Limited | Two small randomised trials on different outcomes |
| Ageing | Very limited | Indirect biomarker studies |
Ratings describe the research as of the update date above. New studies are logged on our new studies log and ratings are revised when the evidence changes.
Hormones and reproduction
These are the claims shilajit is best known for in the UK, and the area with the most human research. “Most” still means a handful of studies.
Testosterone
One randomised, placebo-controlled trial gave 75 healthy men aged 45–55 a purified extract twice daily for 90 days and reported higher total and free testosterone than placebo.[2] It has not been independently replicated, and it says nothing about younger men or about other preparations.
Male fertility
The main human study enrolled 35 men with low sperm counts and compared semen measures before and after 90 days of a processed extract.[3] Without a placebo group, natural variation and other changes can’t be ruled out as explanations.
Libido & sexual function
A triple-blind trial in reproductive-age women reported improved scores on a sexual function questionnaire after 60 days.[4] We have not found a controlled trial in men using libido as the main outcome, despite this being a common marketing claim.
Related: Shilajit for men: evidence overview · “Natural testosterone booster” claims and UK rules
Energy, fatigue and exercise
Shilajit’s traditional reputation as a restorative feeds most of these claims. The modern research is narrower than the marketing suggests.
Energy & fatigue
There is no controlled human trial on everyday tiredness that we are aware of. The nearest human data is muscular fatigue in a laboratory exercise test (see below). Claims about mitochondria and cellular energy draw mainly on laboratory work. Mitochondria research explained.
Exercise & muscle
In an eight-week trial, recreationally active men taking 500 mg a day kept more of their strength after a fatiguing leg exercise than those on placebo; 250 mg a day did not differ from placebo.[5] A separate study looked at muscle gene expression rather than performance.[6]
Brain, sleep and mood
Cognition & memory
A 2012 review set out a hypothesis, based on laboratory and animal work, that shilajit components might be relevant to cognitive ageing.[7] That is a reason for human trials, not evidence of benefit.
Sleep
We have found no human or animal study designed to measure sleep. Sleep claims on product pages are not based on shilajit research.
Stress & mood
The “adaptogen” label comes from traditional use. The research we are aware of is in animals, and no controlled trial has measured stress, anxiety or mood in people.
Bones, joints, metabolism and immunity
Bone health
Sixty postmenopausal women with osteopenia took 250 mg, 500 mg or placebo daily for 48 weeks. Bone mineral density was better preserved in the shilajit groups, more so at the higher dose.[8] One trial, one preparation; it needs replicating.
Inflammation & joints
The bone trial above also reported lower inflammatory and oxidative-stress markers.[8] Markers are not the same as less joint pain, which has not been tested in a controlled human trial that we know of.
Blood sugar, cholesterol & weight
Most of this work is in animal models. We have not found well-designed human trials. Anyone on diabetes medication should not use shilajit as a substitute for treatment.
Immune function
Immune claims trace back to animal and laboratory studies. A 2011 review found that even the antioxidant work underpinning such claims had methodological gaps.[9]
Kidney & urinary health
These claims come from traditional texts. There are no controlled human studies, and people with kidney disease should be particularly cautious about mineral-rich products.
Skin, women’s health and ageing
Skin & hair
A 14-week trial in women aged 30–65 reported changes in skin gene expression and improved skin blood flow at the higher dose.[10] It did not assess wrinkles or appearance. Nothing has been published on hair.
Women’s health
Two small randomised trials, one on bone density after menopause[8] and one on sexual function,[4] plus the skin biomarker study. Pregnancy and breastfeeding have not been studied.
Ageing
“Anti-ageing” claims usually stitch together biomarker results from studies above. No trial has measured healthy ageing outcomes over a meaningful period.
Other topics we cover
Three caveats that apply to every topic
One preparation dominates the human research
Several of the trials on this page used the same branded, standardised extract (PrimaVie), including the testosterone, exercise, skin and bone studies.[2][5][10][8] A result for one controlled extract cannot be assumed for a resin with a different origin and processing. See why research on one preparation may not apply to another.
Funding and replication
When most studies of an ingredient test the same commercial product, it is worth reading each paper’s funding and conflict-of-interest statements. That doesn’t make the results wrong. It does make independent replication more important. We discuss this in who funds shilajit research.
Biomarkers are not outcomes
A change in a blood marker, a gene-expression profile or a lab measure of strength is not the same as feeling better, recovering faster or living longer. Several ratings above are capped for this reason.
Common questions
Does shilajit increase testosterone?
One randomised trial in healthy men aged 45–55 reported an increase compared with placebo after 90 days.[2] That is a single, unreplicated trial of one preparation. It is not enough to say shilajit raises testosterone in general, and UK sellers cannot lawfully market it as a testosterone booster unless the claim is authorised. See testosterone booster claims.
Why don’t you list more benefits?
Because the evidence isn’t there. We list topics people search for and rate them honestly, including the ones with no research at all. A long benefits list built from animal studies and traditional texts would be easy to write and misleading to read.
Are animal studies worthless?
No. They are how researchers decide what is worth testing in people. They just can’t tell you what will happen in a human body at a supplement dose. See human vs animal evidence.
How long did people take shilajit in these studies?
Between eight weeks and 48 weeks in the trials cited here, at daily amounts of roughly 200–500 mg of specific purified or standardised preparations. Studied doses are discussed on studied doses vs label doses.
Sources & further reading
Primary research, regulators and standards bodies are cited first. A source being listed here does not mean it supports every claim made by sellers; it supports the specific statement it is attached to.
- Guyatt GH, Oxman AD, Vist GE, et al.. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ 336(7650):924–926, 2008. doi:10.1136/bmj.39489.470347.AD; PMID 18436948. View source (opens in a new tab) [Methods paper]
- Pandit S, Biswas S, Jana U, De RK, Mukhopadhyay SC, Biswas TK. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia 48(5):570–575, 2016. PMID 26395129. View source (opens in a new tab) [Randomised controlled trial]
- Biswas TK, Pandit S, Mondal S, et al.. Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia. Andrologia 42(1):48–56, 2010. PMID 20078516. View source (opens in a new tab) [Uncontrolled clinical study]
- Mosavi et al.. Effects of oral Shilajit tablets on sexual function and sexual quality of life among reproductive-aged women: a triple-blind randomized clinical trial. Traditional Medicine Research 8(11):66, 2023. View source (opens in a new tab) [Randomised controlled trial]
- Keller JL, Housh TJ, Hill EC, Smith CM, Schmidt RJ, Johnson GO. The effects of Shilajit supplementation on fatigue-induced decreases in muscular strength and serum hydroxyproline levels. Journal of the International Society of Sports Nutrition 16:3, 2019. doi:10.1186/s12970-019-0270-2; PMID 30728074. View source (opens in a new tab) [Randomised controlled trial]
- Das A, et al.. The human skeletal muscle transcriptome in response to oral Shilajit supplementation. Journal of Medicinal Food 19(7):701–709, 2016. doi:10.1089/jmf.2016.0010; PMID 27414521. View source (opens in a new tab) [Human study (gene expression)]
- Carrasco-Gallardo C, Guzmán L, Maccioni RB. Shilajit: a natural phytocomplex with potential procognitive activity. International Journal of Alzheimer’s Disease 2012:674142, 2012. doi:10.1155/2012/674142; PMID 22482077. View source (opens in a new tab) [Review (preclinical)]
- Pingali U, Nutalapati C. Shilajit extract reduces oxidative stress, inflammation, and bone loss to dose-dependently preserve bone mineral density in postmenopausal women with osteopenia: a randomized, double-blind, placebo-controlled trial. Phytomedicine 105:154334, 2022. doi:10.1016/j.phymed.2022.154334; PMID 35933897. View source (opens in a new tab) [Randomised controlled trial]
- Wilson E, Rajamanickam GV, Dubey GP, et al.. Review on shilajit used in traditional Indian medicine. Journal of Ethnopharmacology 136(1):1–9, 2011. doi:10.1016/j.jep.2011.04.033; PMID 21530631. View source (opens in a new tab) [Review]
- Das A, El Masry MS, Gnyawali SC, et al.. Skin transcriptome of middle-aged women supplemented with natural herbo-mineral shilajit shows induction of microvascular and extracellular matrix mechanisms. Journal of the American College of Nutrition 38(6):526–536, 2019. doi:10.1080/07315724.2018.1564088; PMID 31161927. View source (opens in a new tab) [Randomised controlled trial (biomarkers)]