- Humic substances form most of shilajit’s organic matter.[1]
- Three fractions are defined by solubility.
- Humin is largely removed by water extraction.
- The same families occur in soil and peat.
Where humic substances come from
When plant material decomposes, microbes transform it into large, variable organic molecules called humic substances. They occur in soil, peat and sediments as well as in shilajit, where they form the bulk of the organic content.[1] See how shilajit forms.
The three fractions
| Fraction | Solubility | Molecule size (relative) | In purified resin |
|---|---|---|---|
| Fulvic acid | Soluble at all pH levels | Smallest | Retained |
| Humic acid | Soluble when alkaline, precipitates when acidified | Larger | Partly retained |
| Humin | Insoluble | Largest | Largely removed |
Why “operational definition” matters
Because each fraction is defined by what a procedure separates, results depend on the procedure. That’s the root of the problem with comparing fulvic acid percentages from different laboratories; see fulvic acid testing. It also means “humic acid” and “fulvic acid” on a label are categories, not purity claims for a single ingredient.
Reading humic terms on labels and COAs
- Fulvic acid %Check the method; see fulvic acid in shilajit.
- Humic acid %Sometimes listed alongside fulvic acid; the same method caveat applies.
- Total humic substancesA combined figure; useful only with a stated method.
How the fractions are separated in a laboratory
- Dissolve in alkaline solutionFulvic and humic acids dissolve; humin doesn’t and is removed.
- Acidify the solutionHumic acid precipitates and is separated.
- What remains dissolvedIs the fulvic acid fraction.
Laboratories vary the details of each step, which is why results differ between methods. See fulvic acid testing.
Humic substances beyond shilajit
Humic substances are among the most widespread organic materials on Earth. They give soils and peat their dark colour and help bind nutrients and water. Shilajit is unusual because it concentrates them in a resin formed in rock, together with minerals and other metabolites.[1] The comparison helps explain why fulvic acid supplements can be made from sources other than shilajit; see shilajit vs fulvic acid supplements.
Why the fractions matter to consumers
| Fraction | What it tells a buyer |
|---|---|
| Fulvic acid | The most advertised figure; only comparable with the method named |
| Humic acid | Occasionally listed; same method caveat |
| Humin | Low in purified resin; high levels would suggest limited extraction |
Common confusions about humic terms
| Term | What it actually refers to |
|---|---|
| “Humic acid” used for everything | Often used loosely for all humic substances; strictly it’s one fraction |
| Fulvic acid supplements | Products made from humic sources, not necessarily shilajit; see shilajit vs fulvic acid |
| Agricultural humates | Humic products for soil, not for eating |
| Shilajit | A resin combining humic substances with minerals and other metabolites[1] |
When a label uses humic terms, check whether it is describing a measured fraction or using the word loosely. A measured figure should always come with its method.
Frequently asked questions
What is the difference between humic and fulvic acid?
Fulvic acid dissolves at any pH and has smaller molecules; humic acid dissolves only in alkaline conditions and precipitates when acidified.
What is humin?
The fraction of humic substances that doesn’t dissolve at any pH. Water extraction largely removes it.
Is humic acid good for you?
There is no established health benefit of humic acid from shilajit in human studies.
Are humic substances in shilajit the same as in soil?
They belong to the same broad family, but composition differs with the source material and conditions.
Why does purified shilajit contain less humin?
Because humin is insoluble, so it is filtered out with the rock and debris during water extraction.
Do COAs report humic substances?
Some report fulvic and humic acid percentages. Always check the method used.
Where else are humic substances found?
In soil, peat and natural waters. Shilajit concentrates them in a resin formed in mountain rock.[1]
Is fulvic acid a type of humic acid?
Both are fractions of humic substances. People sometimes use “humic acid” loosely for all of them, but strictly they are separate fractions defined by solubility.
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.
- Agarwal SP, et al.. Shilajit: a review. Phytotherapy Research 21(5):401–405, 2007. doi:10.1002/ptr.2100; PMID 17295385. View source (opens in a new tab) [Review]