Shilajit and Fulvic Acid for Male Vitality: One Small Trial, and a Purity Problem
Does shilajit raise testosterone?
One small randomised study of a purified shilajit preparation in healthy volunteers reported higher total and free testosterone after ninety days compared with placebo. That is a real result and it is also a single trial of a single purified product, which is why a systematic review of testosterone boosters treats the ingredient cautiously. Purity is the other half of the story, because unpurified shilajit can carry heavy-metal contamination.
- Human evidence: one small randomised trial over 90 days, plus fertility work.
- Key caveat: a single trial of one purified preparation is not a body of evidence.
- Safety: purification matters - raw material can carry heavy metals.
Shilajit is the most geologically improbable ingredient in the men’s supplement aisle. It is not a plant, not a mineral in the ordinary sense, and not manufactured: it is a tar-like exudate that seeps from rock faces in high mountain ranges, formed over long periods from compressed organic matter. That origin gives it an exotic marketing story and, less conveniently, a genuine purity problem.
It also has something most ingredients in this category lack: a randomised human trial with a testosterone endpoint. This guide covers both halves honestly.
What shilajit actually contains
The characteristic constituents are fulvic and humic acids — complex organic acid mixtures formed by the breakdown of plant material — alongside dibenzo-alpha-pyrones and a variable mineral content. “Fulvic acid” on a label is a marker of shilajit-type material rather than a single defined molecule, which is worth knowing before comparing percentages between products.
Because the source is geological, composition varies with location, and the raw material can carry whatever the rock carried. Purification is therefore a necessary manufacturing step, not a premium feature, and every clinical study worth citing used a purified preparation.
The human trial
The central piece of evidence is a clinical evaluation of purified shilajit on testosterone levels in healthy volunteers. In men aged 45 to 55 taking a purified preparation for ninety days, total and free testosterone were reported higher than in the placebo group. That is a properly designed study with a relevant endpoint in a relevant population, and it is more than most botanicals in this aisle can show.
It is also one study. There is separate work on the spermatogenic activity of processed shilajit in oligospermia reporting improvements in semen parameters, and a more recent study of a shilajit resin supplement examining physical performance and blood biomarkers. A small, consistent, but thin literature is the accurate description — which is why the systematic review asking whether testosterone boosters really raise serum total testosterone treats the whole category, shilajit included, with caution.
| Shilajit | Tongkat ali | Fadogia agrestis | |
|---|---|---|---|
| Randomised human trials | One, on testosterone | Multiple | None |
| Meta-analysis | No | Yes | No |
| Trial duration used | 90 days | Typically 8 to 24 weeks | Not applicable |
| Main quality risk | Heavy metals in unpurified material | Extract standardisation | Product identity and toxicity signal |
| Overall evidence tier | Plausible, thinly evidenced | Modest but real | Preclinical only |
The purity problem, stated properly
This is the part of the shilajit story that deserves more attention than it usually gets. Raw shilajit is collected from rock, and rock contains what rock contains. Unpurified or poorly sourced material has been a recognised route for heavy-metal exposure, which is not a hypothetical concern with a substance intended for daily use over months.
The practical rule is narrow and worth following: buy only preparations described as purified, from sellers who publish third-party testing for heavy metals, and treat an unusually cheap resin with suspicion. This is one of the few supplement categories where a certificate of analysis is a genuine safety document rather than a marketing flourish.
Purified is not a synonym for premium here. Every clinical study of shilajit used a purified preparation. A product that does not describe its purification and testing has not demonstrated that it resembles the material the research studied.
Ask what the label can prove
Ingredient stories are easy; documentation is not. Horse Boost lists nine botanicals inside an 82 mg blend, with only its 5 mg of caffeine broken out, and has not had a trial of its own. Read the ingredients and pricing before you decide.
Order NowHow to place shilajit in a realistic plan
Expect a modest effect at best, over months. The trial ran ninety days. Judging it over three weeks is judging noise, for the reasons set out in how long natural testosterone support takes.
Do not let it displace the basics. Sleep, body composition, training and alcohol account for far more of a man’s hormonal picture than any resin, and they are free.
Watch the total mineral load. Shilajit contributes minerals of its own, and stacking it with a multivitamin and a men’s formula can push individual intakes higher than intended — the same trap documented in the analysis of popular online testosterone boosting supplements, which found products delivering micronutrients above tolerable upper limits.
Inside a blend, the arithmetic changes. The trial used a defined daily dose of a purified preparation. A few milligrams inside a multi-ingredient blend is a different proposition, and the trial cannot be cited as evidence for it — a recurring problem we cover in testosterone boosters for men over 40.
What the evidence shows, and what it does not
What it shows: a randomised trial of purified shilajit reported higher total and free testosterone after ninety days in healthy men aged 45 to 55; separate work reported improvements in semen parameters in oligospermia; purified preparations were generally well tolerated in these studies.
What it does not show: that the finding replicates across independent groups and products, that unpurified material is safe, that any given commercial resin matches the studied preparation, or that shilajit treats diagnosed low testosterone. It is a plausible ingredient with one good study and a real quality-control burden — interesting, unproven, and worth buying carefully if at all. The botanical with the stronger hormonal signal is tongkat ali.
Related reading on male vitality
- How testosterone boosters hold up under audit
- Tongkat ali and the strongest botanical hormone signal
- Minerals, deficiency and testosterone
- How long natural testosterone support takes
Frequently asked questions
What is shilajit made of?
Shilajit is a tar-like exudate that seeps from rock in high mountain ranges, formed over long periods from compressed plant material. Its characteristic components are fulvic and humic acids together with dibenzo-alpha-pyrones and a range of minerals. Because it is a geological rather than a cultivated material, composition varies with source, and purification is a manufacturing step rather than an optional extra.
What did the shilajit testosterone trial show?
A randomised clinical evaluation of purified shilajit in healthy volunteers aged 45 to 55 reported significantly higher total and free testosterone after ninety days of supplementation compared with placebo. It is the strongest single piece of human evidence the ingredient has, and it is one modest trial - not the multiple independent replications that would make the finding dependable.
Is shilajit safe, and what about heavy metals?
Purified preparations used in clinical studies have generally been well tolerated. The concern is with unpurified or poorly sourced material, which can contain heavy metals and other contaminants because the raw substance is collected from rock. This is one of the few supplement categories where third-party testing for heavy metals is genuinely worth insisting on.
How long does shilajit take to work?
The human trials that reported hormonal effects ran for ninety days. That is longer than most botanical studies in this field and is a reasonable minimum for judging it. Anyone expecting a change within a week is applying a stimulant timescale to something that has never been studied as one.
References
- Pandit S et al. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia, 2016. PMID 26395129
- Biswas TK et al. Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia. Andrologia, 2010. PMID 20078516
- Yadav D et al. Safety and Efficacy of TruBlk™ Shilajit Resin Supplementation on Physical Performance and Blood Biomarkers in Healthy Adults: A 28-Day Open-Label Pilot Study. Cureus, 2026. PMID 41613504
- Morgado A et al. Do "testosterone boosters" really increase serum total testosterone? A systematic review. Int J Impot Res, 2024. PMID 37697053
- Balasubramanian A et al. Testosterone Imposters: An Analysis of Popular Online Testosterone Boosting Supplements. J Sex Med, 2019. PMID 30770069
- NIH Office of Dietary Supplements - Dietary Supplements: What You Need to Know
Every PubMed reference above was checked against its own PubMed record before publication. Research on an isolated ingredient is not evidence about any finished product.