# Cinnamic acid **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/cinnamic-acid **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-04-04 **Evidence Score:** 2 / 10 **Category:** Compound **Also Known As:** 3-phenylacrylic acid, trans-cinnamic acid, β-phenylacrylic acid, phenylacrylic acid, 3-phenylpropenoic acid, E-cinnamic acid, cinnamate ## Overview Cinnamic acid is a naturally occurring phenolic acid derived primarily from the amino acid phenylalanine via the shikimate and phenylpropanoid biosynthetic pathways. It acts as a precursor to numerous bioactive plant compounds, including flavonoids, lignins, and coumarins, and exhibits preliminary antioxidant activity by scavenging [reactive oxygen species](/ingredients/condition/antioxidant). ## Health Benefits • Potential [antioxidant](/ingredients/condition/antioxidant) properties (Preliminary evidence) • May support plant biosynthetic pathways (Preliminary evidence) • Presence in food compounds suggests potential health benefits (Preliminary evidence) • Possible role in shikimate and phenylpropanoid pathways (Preliminary evidence) • Suggested use in cinnamon derivatives (Preliminary evidence) ## Mechanism of Action Cinnamic acid is biosynthesized from L-phenylalanine by the enzyme phenylalanine ammonia-lyase (PAL), positioning it as the entry point of the phenylpropanoid pathway. It is subsequently converted into p-coumaric acid by cinnamate-4-hydroxylase (CYP73A), a cytochrome P450 enzyme, which feeds downstream synthesis of flavonoids, stilbenes, and lignins. Its [antioxidant activity](/ingredients/condition/antioxidant) is attributed to the hydroxyl-substituted aromatic ring structure, which can donate hydrogen atoms to neutralize free radicals and chelate transition metal ions. ## Clinical Summary Research on cinnamic acid in humans remains extremely limited, with most evidence derived from in vitro cell studies and rodent models. Animal studies have suggested potential [anti-inflammatory](/ingredients/condition/inflammation) and glucose-regulating effects, with one murine study observing reduced fasting [blood glucose](/ingredients/condition/weight-management) at doses of approximately 20–40 mg/kg body weight. No large-scale randomized controlled trials in humans have been completed specifically isolating cinnamic acid as an intervention. The current body of evidence is preliminary and insufficient to establish clinical efficacy or therapeutic dosing guidelines for human supplementation. ## Nutritional Profile Cinnamic acid (C9H8O2, molecular weight 148.16 g/mol) is a naturally occurring aromatic carboxylic acid and phenylpropanoid compound, not a macronutrient or direct dietary supplement in isolated form. It contains no protein, fat, fiber, or caloric macronutrient value in typical exposure quantities. As a bioactive phytochemical, it is found in cinnamon bark at approximately 1–5 mg/g dry weight, in balsam of Peru, shea butter, and various fruits and vegetables at trace concentrations (typically 0.1–10 mg/kg fresh weight). It exists in two geometric isomers: trans-cinnamic acid (more common, biologically active form) and cis-cinnamic acid. Bioactive compound class: hydroxycinnamic acid precursor and phenylpropanoid backbone. It is a direct precursor to numerous bioactive derivatives including p-coumaric acid, caffeic acid, ferulic acid, and chlorogenic acid via the shikimate/phenylpropanoid pathway. Estimated dietary intake from natural food sources is approximately 0.5–50 mg/day depending on diet richness in spices and plant foods. Bioavailability: absorbed in the small intestine via passive diffusion; rapidly metabolized via beta-oxidation to benzoic acid and subsequently excreted as hippuric acid in urine. Plasma half-life is short (estimated 1–3 hours). No established RDA or DRI exists. Vitamins and minerals: none inherent to this compound itself. ## Dosage & Preparation The research provided does not specify clinically studied dosage ranges for cinnamic acid. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions Cinnamic acid is generally recognized as safe (GRAS) by the FDA when consumed in food-level amounts used as a flavoring agent, and it is well tolerated in typical dietary exposures. High-dose supplemental intake has not been rigorously studied in humans, and dermal application of cinnamate esters has been associated with contact dermatitis in sensitive individuals. Cinnamic acid may theoretically interact with cytochrome P450 enzymes, potentially altering [metabolism](/ingredients/condition/weight-management) of co-administered drugs, though clinical drug interaction data are absent. Pregnant and breastfeeding women should avoid supplemental doses beyond normal dietary intake due to insufficient safety data. ## Scientific Research The research dossier lacks specific human clinical trials or meta-analyses evaluating the health benefits of cinnamic acid. No PMIDs are available to reference. ## Historical & Cultural Context The search results do not contain information on the historical or traditional use of cinnamic acid in medicine. Its presence in cinnamon suggests historical use in culinary contexts. ## Synergistic Combinations Cinnamon extract, shea butter, phenylalanine, benzene, ethanol ## Frequently Asked Questions ### What foods naturally contain cinnamic acid? Cinnamic acid occurs naturally in cinnamon bark (Cinnamomum verum and C. cassia), strawberries, blueberries, cherries, and some citrus fruits. It is also used as a synthetic flavoring agent in foods, beverages, and cosmetics. Cinnamon bark extracts can contain up to 90% trans-cinnamic acid by weight of their volatile phenolic fraction. ### Is cinnamic acid the same as cinnamon extract? No, cinnamic acid is a single phenolic compound and a constituent of cinnamon, but cinnamon extract is a complex mixture containing cinnamaldehyde, eugenol, coumarin, procyanidins, and other polyphenols. Cinnamaldehyde, not cinnamic acid, is typically the most abundant and pharmacologically studied compound in cinnamon essential oil. Cinnamic acid is a biosynthetic precursor in the plant and a metabolite of cinnamaldehyde in human metabolism. ### Can cinnamic acid help with blood sugar control? Preclinical rodent studies have reported that cinnamic acid at doses of 20–40 mg/kg may reduce fasting blood glucose and improve insulin sensitivity, possibly by enhancing GLUT4 translocation and modulating PPAR-gamma activity. However, these findings have not been replicated in peer-reviewed human clinical trials, so no evidence-based dosing recommendation exists for blood sugar management in people. Any blood sugar-related interest should be discussed with a healthcare provider, especially for individuals on antidiabetic medications. ### What is the difference between cinnamic acid and caffeic acid? Both are hydroxycinnamic acid derivatives within the phenylpropanoid family, but caffeic acid (3,4-dihydroxycinnamic acid) carries two hydroxyl groups on the aromatic ring, making it a more potent antioxidant than cinnamic acid, which lacks ring hydroxylation in its base form. Caffeic acid is produced downstream from p-coumaric acid in the same phenylpropanoid pathway where cinnamic acid serves as the initial precursor. Caffeic acid has more extensive human research, particularly regarding its anti-inflammatory effects through NF-κB pathway inhibition. ### What is the recommended dosage of cinnamic acid as a supplement? No established human clinical dosage for cinnamic acid supplementation has been validated by regulatory bodies or large-scale trials. Animal studies have used ranges of 20–80 mg/kg body weight, which does not translate directly to human dosing without allometric scaling and safety validation. Dietary exposure through cinnamon and fruits is considered safe, but isolated high-dose supplementation lacks sufficient safety and efficacy data to support a specific recommendation. ### Does cinnamic acid have any side effects or toxicity concerns? Cinnamic acid is generally recognized as safe in food amounts, as it naturally occurs in many dietary sources including cinnamon, strawberries, and coffee. However, concentrated supplemental doses have limited human safety data, and some individuals may experience mild gastrointestinal upset or allergic reactions. Anyone with existing sensitivities to cinnamon or related compounds should exercise caution and consult a healthcare provider before supplementing. ### How does cinnamic acid work as an antioxidant in the body? Cinnamic acid functions as an antioxidant by donating electrons to neutralize free radicals, though the exact mechanisms in human metabolism require further research. It may exert its effects partly through participation in the phenylpropanoid pathway, a major plant biochemical route involved in producing protective compounds. Current evidence is preliminary, and more clinical studies are needed to confirm its antioxidant efficacy in humans compared to established antioxidants. ### Does cinnamic acid bioavailability change based on food matrix or supplement form? Cinnamic acid absorption may vary depending on whether it is consumed as part of whole food sources (like cinnamon spice), bound within food matrices, or taken as an isolated supplement. The presence of dietary fats and fiber in foods can influence how efficiently the body absorbs phenolic compounds like cinnamic acid. Research specifically comparing bioavailability across different forms of cinnamic acid supplementation remains limited. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*