indole-3-propionic acid

Indole-3-propionic acid (IPA) is a gut microbiota-derived metabolite of tryptophan, classified as an indolyl carboxylic acid. It is a small molecule with potent antioxidant properties, surpassing melatonin in scavenging hydroxyl radicals without generating prooxidant intermediates. IPA has demonstrated neuroprotective, anti-inflammatory, and anti-fibrotic effects in preclinical studies. It acts as an allosteric inhibitor of tryptophan biosynthesis in bacteria and modulates host metabolism by binding to the aryl hydrocarbon receptor (AHR), influencing pathways such as SIRT3-mediated mitochondrial function and the nicotinamide adenine dinucleotide salvage pathway. IPA has been investigated for its potential therapeutic roles in Alzheimer's disease, heart failure with preserved ejection fraction (HFpEF), metabolic syndrome, type 2 diabetes, liver fibrosis/non-alcoholic fatty liver disease (NAFLD), Friedreich ataxia, and diminished ovarian reserve[1][4][5][7][8]. As of June 2025, it remains investigational with no approved pharmaceutical indications.

Brand names

Oxigon

Other names

3-indolepropionic acid3-(1H-indol-3-yl)propanoic acidindolylpropionic acid