# 4-Hydroxybenzoic acid **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/4-hydroxybenzoic-acid **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-03-28 **Evidence Score:** 2 / 10 **Category:** Compound **Also Known As:** para-Hydroxybenzoic acid, PHBA, p-Hydroxybenzoic acid, 4-HBA, Benzoic acid, 4-hydroxy-, p-Carboxyphenol, 4-Carboxyphenol ## Overview 4-Hydroxybenzoic acid is a phenolic compound that serves as a substrate for the enzyme monoamine oxidase B (MAOB). Despite good absorption and blood-brain barrier permeability, no clinical health benefits have been documented in human studies. ## Health Benefits • No clinical health benefits documented - available research only describes enzyme interactions (PMID:11049757) • Substrate for amine oxidase enzyme MAOB - biochemical role only, no therapeutic evidence • High intestinal absorption (0.9872) and blood-brain barrier permeability (0.532) - pharmacokinetic properties only • Component of ubiquitous natural occurrence in foods - nutritional exposure, not therapeutic benefit • No human clinical trials, RCTs, or meta-analyses available for health claims ## Mechanism of Action 4-Hydroxybenzoic acid functions as a substrate for monoamine oxidase B (MAOB), an enzyme involved in [neurotransmitter](/ingredients/condition/cognitive) [metabolism](/ingredients/condition/weight-management). The compound demonstrates high intestinal absorption (0.9872) and moderate blood-brain barrier permeability (0.532). However, these biochemical interactions have not translated into documented therapeutic effects in clinical research. ## Clinical Summary Current research on 4-hydroxybenzoic acid is limited to enzyme interaction studies, with PMID:11049757 describing its role as an MAOB substrate. No randomized controlled trials have evaluated health benefits in human subjects. The available evidence consists only of pharmacokinetic and biochemical studies examining enzyme interactions. Clinical efficacy remains unestablished despite favorable absorption properties. ## Nutritional Profile 4-Hydroxybenzoic acid (4-HBA) is a phenolic acid compound (molecular formula C7H6O4, MW 138.12 g/mol), not a macronutrient or conventional micronutrient. It is a naturally occurring hydroxylated benzoic acid derivative found ubiquitously in plant-based foods. Macronutrient content: negligible (consumed in trace/microgram quantities, not as a caloric source). Protein, fat, fiber content: not applicable as an isolated compound. Bioactive compound classification: simple phenolic acid / benzoic acid derivative with a para-hydroxyl group. Naturally occurring concentrations in foods: approximately 0.1–5 mg/kg in olives, olive oil, red wine, berries (blueberries, raspberries), black radish, and some fermented foods; detected at lower levels in green tea and some spices. Also produced endogenously as a microbial metabolite from polyphenol fermentation in the gut (e.g., from hydrolysis of esters like p-hydroxybenzoate esters). Pharmacokinetic profile: high intestinal absorption (predicted absorption coefficient 0.9872), blood-brain barrier permeability coefficient 0.532 (moderately permeable), suggesting near-complete gastrointestinal uptake when ingested. Acts as a biochemical substrate for monoamine oxidase B (MAOB) enzyme. No established Dietary Reference Intake (DRI) or Recommended Daily Allowance (RDA) exists. Typical estimated dietary intake from food sources is in the range of low micrograms to low milligrams per day depending on diet composition. ## Dosage & Preparation No clinically studied dosage ranges, forms, or standardization details are available as no human trials have been documented. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions Safety data for 4-hydroxybenzoic acid supplementation is limited due to lack of human clinical trials. Its interaction with monoamine oxidase B suggests potential effects on [neurotransmitter](/ingredients/condition/cognitive) [metabolism](/ingredients/condition/weight-management), which could theoretically interact with MAO inhibitor medications. Pregnant and breastfeeding women should avoid supplementation due to insufficient safety data. Individuals taking antidepressants or other neuropsychiatric medications should consult healthcare providers before use. ## Scientific Research No human clinical trials, RCTs, or meta-analyses have been identified for 4-hydroxybenzoic acid as a therapeutic agent. The PMIDs mentioned (11049757, 11134050, 20493079, 8316221, 8665924) relate only to enzyme interaction studies, not clinical outcomes. ## Historical & Cultural Context No historical context, traditional medicine systems, or documented durations of use are available in the research sources. The compound's traditional applications remain undocumented. ## Synergistic Combinations No synergistic compounds identified in available research ## Frequently Asked Questions ### What does 4-hydroxybenzoic acid do in the body? 4-Hydroxybenzoic acid acts as a substrate for monoamine oxidase B (MAOB), an enzyme that breaks down certain neurotransmitters. It has high intestinal absorption (0.9872) and can cross the blood-brain barrier, but these interactions haven't produced documented health benefits. ### Is 4-hydroxybenzoic acid effective for any health conditions? No clinical health benefits have been documented for 4-hydroxybenzoic acid. Research is limited to biochemical studies showing enzyme interactions, with no human trials demonstrating therapeutic effects for any medical conditions. ### Can 4-hydroxybenzoic acid interact with medications? Due to its interaction with monoamine oxidase B, 4-hydroxybenzoic acid may potentially interfere with MAO inhibitor medications and other drugs affecting neurotransmitter metabolism. Anyone taking psychiatric medications should consult their doctor before use. ### What is the recommended dosage of 4-hydroxybenzoic acid? No established dosage recommendations exist for 4-hydroxybenzoic acid since it lacks proven therapeutic benefits. The compound has not undergone clinical trials to determine safe or effective dosing ranges for human supplementation. ### Where does 4-hydroxybenzoic acid come from naturally? 4-Hydroxybenzoic acid is a phenolic compound found naturally in various plants as part of their secondary metabolite profile. However, specific food sources and natural concentrations have not been extensively documented in nutritional literature. ### What foods naturally contain 4-hydroxybenzoic acid? 4-hydroxybenzoic acid occurs naturally in a wide variety of foods including berries, nuts, whole grains, and fermented products like yogurt and cheese. It is also found in common beverages such as tea and coffee, meaning most people obtain dietary exposure to this compound through normal food consumption. The amount present in foods is typically small and varies depending on the food source and processing methods used. ### Is 4-hydroxybenzoic acid safe for pregnant women or children? Safety data specifically addressing 4-hydroxybenzoic acid use during pregnancy or in children is limited, as this compound is primarily studied for its biochemical interactions rather than therapeutic applications. Since it occurs naturally in many common foods, incidental dietary exposure is generally considered part of normal nutrition. Anyone considering supplementation during pregnancy, nursing, or for children should consult with a healthcare provider due to insufficient targeted safety research. ### How well does the body absorb 4-hydroxybenzoic acid? 4-hydroxybenzoic acid demonstrates high intestinal absorption rates (approximately 98.7%), meaning the body efficiently takes it up from dietary sources and supplements. The compound also crosses the blood-brain barrier with moderate permeability (0.532), allowing it to reach central nervous system tissues. This favorable pharmacokinetic profile means that when consumed, 4-hydroxybenzoic acid is readily available for biological interactions within the body. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*