Humic Acid

The high-molecular-weight fraction of humic substances and the single most important bioactive compound class in therapeutic and cosmetic peat. Soluble in alkaline conditions but precipitates out below pH 2 — this pH-dependent solubility is what separates it, by definition, from fulvic acid and what makes it extractable via the classic alkaline-extraction/acid-precipitation method.

Plain-Language Summary

Dark brown to black in color, large in molecular size, and formed only through the slow anaerobic humification process — humic acid does not exist in fresh plant material, only in well-decomposed peat (von Post grade H6 or higher). It is the main reason a peat deposit’s degree of humification is treated as its most important quality marker: more humification generally means more humic acid.

What It Does

Humic acid is a multi-mechanism compound — the same molecule shows anti-inflammatory, antioxidant, antimicrobial, immunomodulatory, and metal-chelating activity, mediated largely through its carboxyl and phenolic hydroxyl functional groups. This is the compound behind Poland’s Tołpa Peat Preparation (TPP), the most pharmacologically studied peat-derived product on record, and the primary reason German/Austrian Heilmoor peat is required to meet a minimum humic acid content.

Where the Data Lives

This page is a plain-language orientation. For the full evidence-graded list of biological activities and the specific studies behind each claim, see Humic Acids.