What shilajit does: what the trials measured and what your blood shows

What shilajit does to testosterone has been measured in exactly one good trial in humans. Healthy men aged 45 to 55 took purified shilajit for 90 days, 250 mg twice a day. Total testosterone, free testosterone and DHEA-S were then higher than on placebo (Pandit 2016, PMID 26395129). LH and FSH stayed level.

What strikes me as a training partner? Almost every Dutch page cites that one trial as if there were ten. I read it properly once, below.

Below is what shilajit is and what that trial measured exactly. Where the risk sits, and what you can measure yourself.

What is shilajit?

Shilajit is a black, tar-like resin. In summer it seeps out of rocks in the Himalayas and other high mountain ranges. It is not a plant but a mixture of centuries-old plant material and minerals. In Ayurveda it has long been used as a tonic.

The best-known active compound is fulvic acid, often 50 to 60 percent of a purified extract. It also contains dozens of minerals in small amounts. You buy it as resin, as powder or as a capsule.

Unpurified resin can contain heavy metals such as lead and arsenic. That is not a theoretical risk. It is the reason the trial used a purified product.

What the trial measured exactly

Pandit gave healthy men aged 45 to 55 purified shilajit or a placebo for ninety days. The dose was 250 mg twice a day.

At the end, total testosterone, free testosterone and DHEA-S were significantly higher than on placebo. That is in Pandit's trial (2016, PMID 26395129). LH and FSH, the hormones that drive the testes, stayed the same.

That last point is interesting. A rise in testosterone without a rise in LH points to an effect in the testis itself. Not in the brain. That is a different mechanism from most boosters.

What the trial did not do: measure young, trained men. The participants were healthy, but 45 to 55 years old. That is exactly the age at which testosterone starts to decline. Whether a 28-year-old with normal values sees the same, nobody knows.

And it is one trial. In science a result only counts once a second group repeats it. That second trial does not exist.

What are people's experiences with shilajit?

Experiences on forums and in reviews range from more energy and more desire to nothing at all. You see that pattern with every supplement. An experience is not a measurement, and energy is the easiest thing to sway by expectation.

What you can take seriously: reports of stomach complaints and a metallic taste, especially with raw resin. And the recurring question of whether the product was pure.

How long can you use shilajit?

The trial lasted 90 days, and longer than that has not been studied in humans. So that is the only period you know anything about. Anyone using it longer is doing so without data.

EFSA has not authorised a health claim for shilajit. A seller is therefore not allowed to claim it raises your testosterone. However often the trial is cited.

What are the downsides of shilajit?

The biggest downside is purity. Shilajit from an unknown source can contain lead, arsenic and mercury. You notice nothing of that at first. If you choose it anyway, a product with an independent heavy-metal analysis is the minimum.

The second downside is the liver. Every concentrated natural product passes through your liver. The Dutch RIVM warned against ashwagandha in March 2024 for a reason: reports of liver damage. With shilajit such reports are rare, but your liver values are the place to see it.

The third downside is the price. Purified resin easily costs tens of euros a month. That is for an effect that may not occur in you.

Can I lose weight with shilajit?

No, there is no evidence for that. The trial measured hormones, not weight or body fat. Anyone who loses weight while using shilajit does so through food and training, not through the resin.

A lower body fat percentage does raise your testosterone, by the way, through less conversion to estrogen. That effect is bigger and better proven than shilajit's.

What to measure before and after

Imagine you are 47 and you train three times a week. You want to know whether shilajit does for you what it did for the trial group. Then you measure twice, in the morning between 7 and 10, 90 days apart.

Total testosterone, free testosterone and SHBG come together in the hormone panel. The other values are measured separately via the biomarker pages. Liver values are measured separately or as an add-on to 360 health. For total testosterone alone, the testosterone test is enough.

If your testosterone rises, you saw what Pandit saw. If it stays the same, you belong to the group the trial says nothing about. Either is more useful than guessing.

What you can do with this

My line: shilajit is one of the few boosters with a real, measured rise. At the same time it is the supplement with the biggest purity risk. One trial, one age group, and a product I would only buy with an analysis report.

The Dutch Voedingscentrum says of supplements: a healthy, varied diet makes most of them unnecessary. How shilajit compares with the other boosters is in the overview of testosterone supplements. Ashwagandha, with more trials and an RIVM advisory, is in ashwagandha and testosterone.

If a value is off, discuss it with your GP and mention which supplements you take. Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

References

• Pandit S, Biswas S, Jana U, De RK, Mukhopadhyay SC, Biswas TK. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia. 2016 (PMID 26395129).
• RIVM. RIVM raadt gebruik producten met kruiden Huperzia serrata, Tabernanthe iboga of ashwagandha af. 5 March 2024.
• EFSA. EU Register of nutrition and health claims. ec.europa.eu/food/safety/labelling_nutrition/claims/register.
• Voedingscentrum. Voedingssupplementen. voedingscentrum.nl.