Humic Acid

Last Editorial Review: 6/11/2021
Other Name(s):

Acide Humique, Ácidos Húmicos, Extracto de Húmicos, Extrait d'Humique, Humate, Humic Extract.


Humic acid is a chemical produced by decaying plants. People use it to make medicine.

People take humic acid for stimulating the immune system and treating the flu (influenza), avian flu, swine flu, and other viral infections.

How does it work?

There isn't enough information available to know how humic acid works.


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Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

  • Stimulating the immune system.
  • Treating viral diseases.
  • Other conditions.
More evidence is needed to rate the effectiveness of humic acid for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

There isn't enough information available to know if humic acid is safe. Laboratory research and population research has associated humic acid with joint disease, circulatory disease, and thyroid disease.


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Special Precautions & Warnings

Pregnancy and breast-feeding: Not enough is known about the use of humic acid during pregnancy and breast-feeding. Stay on the safe side and avoid use.

“Auto-immune diseases” such as multiple sclerosis (MS), lupus (systemic lupus erythematosus, SLE), rheumatoid arthritis (RA), or other conditions: Humic acid might cause the immune system to become more active, and this could increase the symptoms of auto-immune diseases. If you have one of these conditions, it's best to avoid using humic acid.


The appropriate dose of humic acid depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for humic acid. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.


Chen CH, Liu JJ, Lu FJ, et al. The effect of humic acid on the adhesibility of neutrophils. Thromb Res 2002;108:67-76. View abstract.

Cheng ML, Ho HY, Huang YW, et al. Humic acid induces oxidative DNA damage, growth retardation, and apoptosis in human primary fibroblasts. Exp Biol Med (Maywood) 2003;228:413-23. View abstract.

Hseu YC, Huang HW, Wang SY, et al. Humic acid induces apoptosis in human endothelial cells. Toxicol Appl Pharmacol 2002;182:34-43. View abstract.

Joone GK, Dekker J, van Rensburg CE. Investigation of the immunostimulatory properties of oxihumate. Z Naturforsch [C] 2003;58:263-7. View abstract.

Laurberg P, Andersen S, Pedersen IB, et al. Humic substances in drinking water and the epidemiology of thyroid disease. Biofactors 2003;19:145-53. View abstract.

Liang HJ, Tsai CL, Chen PQ, Lu FJ. Oxidative injury induced by synthetic humic acid polymer and monomer in cultured rabbit articular chondrocytes. Life Sci 1999;65:1163-73. View abstract.

Lu FJ, Lee YS. Humic acid: inhibitor of plasmin. Sci Total Environ 1992;114:135-9. View abstract.

Lu FJ, Tseng SN, Li ML, Shih SR. In vitro anti-influenza virus activity of synthetic humate analogues derived from protocatechuic acid. Arch Virol 2002;147:273-84. View abstract.

Schneider J, Weis R, Manner C, et al. Inhibition of HIV-1 in cell culture by synthetic humate analogues derived from hydroquinone: mechanism of inhibition. Virology 1996;218:389-95. View abstract.

van Rensburg CE, Dekker J, Weis R, et al. Investigation of the anti-HIV properties of oxihumate. Chemotherapy 2002;48:138-43. View abstract.