# Fulvic acid

> Fulvic acid is the small, soluble fraction of humic substances that stays dissolved at any pH and binds metal ions; its benefit in cannabis is largely unproven.

- Canonical: https://genetixbay.com/knowledge/glossary/fulvic-acid.html
- Also written: fulvic acids, fulvates, fulvic
- Glossary category: Nutrients · Evidence: Contested
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Fulvic acid is the fraction of [humic substances](https://genetixbay.com/knowledge/glossary/humic-acid.md) that remains soluble at all [pH](https://genetixbay.com/knowledge/glossary/ph.md) values. Its molecules are smaller and richer in oxygen-containing acid groups than humic acid, so it binds metal ions and moves more freely in water. It is usually yellow to golden brown.

## In practice

It is sold as a nutrient carrier, [foliar](https://genetixbay.com/knowledge/glossary/foliar-feeding.md) additive and "uptake enhancer". It does complex [micronutrients](https://genetixbay.com/knowledge/glossary/micronutrient.md), which may help keep them soluble. Claims that it dramatically improves uptake, yield or quality in cannabis lack controlled trials (Evidence: Contested). Products vary widely in source and concentration, and the analytical methods for "fulvic content" are not standardised, so labels are hard to compare. Small doses are generally harmless; treat any large claims with suspicion.

## Don't confuse with

- **Humic acid**: the larger fraction that precipitates at low pH.
- **Synthetic chelates**: defined chemicals with known stability.
- **Shilajit or similar supplements**: human products marketed with fulvic claims, unrelated to plant feeding.

## Myth check

Label claims for fulvic products often outrun the evidence. See [buyer beware: label claims](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md).

## Related terms

[Humic acid](https://genetixbay.com/knowledge/glossary/humic-acid.md), [Chelate](https://genetixbay.com/knowledge/glossary/chelate.md), [Foliar feeding](https://genetixbay.com/knowledge/glossary/foliar-feeding.md), [Biostimulant](https://genetixbay.com/knowledge/glossary/biostimulant.md)

## Read more

- [Organic vs mineral nutrition for cannabis: what the trials show](https://genetixbay.com/knowledge/nutrients/organic-vs-mineral.md)

## Sources

1. Marschner P (ed.). 2012. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. Academic Press. https://doi.org/10.1016/C2009-0-63043-9