Fulvic acid in shilajit: what it is and does

Fulvic acid is the ingredient shilajit sellers talk about most, and the number most labels are built around. It is a humic substance: one of the organic compounds left behind when plant matter decays over long periods. It is also found in soil, peat and water, and it can be made in a lab. In shilajit it is the largest single part of the organic fraction, and researchers have long suspected it is behind many of shilajit’s effects.

That suspicion is reasonable but unproven. Most of what we know about fulvic acid comes from test tubes and animals. The few human trials of fulvic acid used a lab-made version, not fulvic acid from shilajit, and no trial has compared fulvic acid alone with whole shilajit. For the rest of shilajit’s chemistry, see what shilajit is made of.

What is fulvic acid?

It is the smallest, most water-soluble part of the humic material in shilajit. When researchers fractionated mumie (another name for shilajit), they separated fulvic acid from humic acid, humin and other fractions (Schepetkin et al., 2003). Fulvic acid dissolves in water under a range of acidity levels and has a low molecular weight, around 2 kDa. One review says this means it is well absorbed from the gut and eliminated from the body within hours (Carrasco-Gallardo et al., 2012), though that review did not present new human data on it.

Fulvic acid is not a single molecule. It is a family of related compounds whose make-up depends on where it came from, which is one reason results from one product don’t automatically apply to another.

How much fulvic acid does shilajit contain?

It varies enormously. Humic substances as a group make up more than 80% of shilajit by weight in one review (Kamgar et al., 2025) and 60% to 80% in another (Carrasco-Gallardo et al., 2012). How much of that is fulvic acid depends on the source and processing:

Different labs use different test methods, so percentages from different products are not always comparable. A label claiming a very high fulvic acid content should state the method and be backed by a certificate of analysis.

What does fulvic acid do in the body?

We don’t really know in people. The research so far is mostly laboratory work:

• Immune effects. Fulvic acid fractions from mumie increased production of reactive oxygen species and nitric oxide in mouse immune cells, and stimulated mouse lymphocytes to divide (Schepetkin et al., 2003).
• Complement system. Fulvic acid fractions from commercial shilajit strongly “fixed” complement, part of the immune system involved in inflammation, in test tubes. The effect tracked the number of carboxylic acid groups (Schepetkin et al., 2009).
• Tau protein. In a test tube, fulvic acid reduced the clumping of tau, a protein that forms tangles in Alzheimer’s disease, and broke up fibres that had already formed (Cornejo et al., 2011). That is a long way from showing any benefit for memory; see shilajit and brain health.
• Inflammation. A review of humic substances describes anti-inflammatory effects in rats, and lower inflammation markers or allergy responses in small studies of people with knee osteoarthritis and hay fever (van Rensburg, 2015).

A 2014 review of shilajit named fulvic acid and dibenzo-alpha-pyrones as the constituents that “appear to be” responsible for its effects (Stohs, 2014). “Appear to be” is the right level of confidence.

Has fulvic acid been tested in humans?

Only in a lab-made form, and only in small, short studies. Carbohydrate-derived fulvic acid (CHD-FA) is made by oxidising sugar, so it contains none of shilajit’s minerals or other compounds (Clark and Graz, 2026).

• Safety study. 30 men with allergies took increasing doses, then 40 mL of a 3.8% solution twice daily for a week, against placebo. Safety tests stayed normal, no serious side effects occurred, and skin prick test reactions decreased (Gandy et al., 2012).
• Eczema. In 36 people using CHD-FA on the skin twice daily for 4 weeks, it was well tolerated apart from brief burning, and some measures improved more than with placebo (Gandy et al., 2011).

These studies tell us little about swallowing shilajit, but they are the only human trials of fulvic acid itself that we found.

Does fulvic acid help absorb minerals or medicines?

It can bind to them, which is where the “carrier” claim comes from, but that has not been shown to improve nutrition in people. Pharmacy researchers have used fulvic acid extracted from shilajit to form complexes with the water tablet furosemide (Agarwal et al., 2008) and the epilepsy drug carbamazepine, improving solubility and absorption in lab and rodent tests (Mirza et al., 2011). The flip side is that fulvic acid could change how some medicines are absorbed. See shilajit drug interactions.

Is fulvic acid safe?

At supplement doses it looks low-risk, with caveats. A 2015 review states that fulvic acid “is safe in humans up to a daily dosage of 1.8 g per adult” (van Rensburg, 2015). A lab-made version showed no genotoxicity in standard tests, apart from a weak effect in human lymphocytes that the authors attributed to the test conditions; both authors work for the company that makes it (Clark and Graz, 2026).

Two cautions. First, natural fulvic acid carries whatever its source contains, including heavy metals, which is why shilajit needs testing (Hussain and Saeed, 2024). Second, in parts of China, fulvic acid in drinking water is one of four hypotheses researchers have proposed for Kashin-Beck disease, a joint and cartilage disorder (Yu et al., 2022). That is a hypothesis about long-term environmental exposure, not evidence that supplements cause it, but it is a reminder that “natural” does not mean harmless.

Should I buy fulvic acid or shilajit?

They are different products. Fulvic acid supplements contain one fraction, which may come from peat (Gnananath et al., 2020) or another source. Shilajit contains fulvic acid plus minerals and other compounds, and it is shilajit, in standardised extract form, that has been tested in the human trials described on our benefits pages. Neither has strong evidence behind it. Whichever you choose, look for a stated content, a test method and a batch lab certificate. More context is on our what is shilajit page.