# Rhapontigenin **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/rhapontigenin **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-03-30 **Evidence Score:** 2 / 10 **Category:** Compound **Also Known As:** 3,5-dihydroxy-4'-methoxystilbene, 4'-methoxy-3,5-dihydroxystilbene, Rhaponticin aglycone, 3,5-Dihydroxy-4'-methoxy-trans-stilbene, Stilbenoid polyphenol ## Overview Rhapontigenin is a stilbene compound found in rhubarb that exhibits anti-cancer and anti-angiogenic properties through inhibition of HIF-1α accumulation. This bioactive polyphenol demonstrates selective estrogen receptor modulation and tyrosinase inhibition in preclinical studies. ## Health Benefits • Inhibits HIF-1α accumulation and angiogenesis in prostate cancer cells (preclinical evidence). • Suppresses breast cancer cell migration by inhibiting the PI3K/Rac1 pathway (in vitro studies). • Shows dose-dependent tyrosinase inhibition in melanoma cells (cell-based study). • Acts as a selective inactivator of cytochrome P450 1A1 (IC50: 400 nM, experimental evidence). • Inhibits colorectal adenocarcinoma cell growth (preclinical models). ## Mechanism of Action Rhapontigenin inhibits hypoxia-inducible factor-1α (HIF-1α) accumulation, which suppresses angiogenesis and tumor growth in cancer cells. It blocks the PI3K/Rac1 signaling pathway to prevent cancer cell migration and metastasis. The compound also acts as a competitive tyrosinase inhibitor and demonstrates selective estrogen receptor β (ERβ) agonist activity. ## Clinical Summary Current research on rhapontigenin is limited to preclinical in vitro and cell culture studies. Studies show dose-dependent inhibition of prostate cancer angiogenesis and breast cancer cell migration at concentrations of 10-50 μM. Tyrosinase inhibition studies demonstrate IC50 values around 15-25 μM in melanoma cell lines. No human clinical trials have been conducted to establish safety, efficacy, or optimal dosing in humans. ## Nutritional Profile Rhapontigenin (3,3',5-trihydroxy-4'-methoxystilbene) is a naturally occurring stilbenoid compound, not a conventional food ingredient with macronutrient or micronutrient content. It is a low-molecular-weight polyphenol (MW: 258.27 g/mol) classified as a hydroxystilbene. Key bioactive profile: It is structurally analogous to resveratrol with an additional methoxy group at the 4' position, which confers distinct pharmacological selectivity. Found naturally in rhubarb (Rheum rhaponticum, Rheum undulatum) at trace concentrations, typically in the range of 0.01–0.5 mg/g dry weight in root extracts, depending on species and extraction method. No meaningful macronutrient (carbohydrate, fat, protein) or micronutrient (vitamin, mineral) content is attributable to rhapontigenin itself as an isolated compound. Bioavailability notes: As a stilbenoid, rhapontigenin is subject to phase I and phase II hepatic [metabolism](/ingredients/condition/weight-management); it is notably a mechanism-based inactivator of CYP1A1 (IC50: ~400 nM), suggesting potential for metabolic interactions that could affect its own clearance and that of co-administered substrates. Oral bioavailability is expected to be moderate, consistent with other stilbenes, with significant first-pass metabolism; precise human pharmacokinetic data are limited. Gut microbiota may further metabolize stilbenoids, though rhapontigenin-specific microbial transformation data are sparse. ## Dosage & Preparation There are no clinically studied dosage ranges due to the absence of human trials. Preclinical studies use nanomolar to micromolar concentrations in cell models. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions Safety data for rhapontigenin supplementation in humans is lacking due to the absence of clinical trials. Potential estrogenic activity through ERβ modulation may contraindicate use in hormone-sensitive conditions or during pregnancy and breastfeeding. Drug interactions are unknown but may theoretically affect medications metabolized through pathways involving PI3K or HIF-1α. Consultation with healthcare providers is recommended before supplementation, especially for individuals with cancer or taking chemotherapy medications. ## Scientific Research No human clinical trials, RCTs, or meta-analyses have been conducted on rhapontigenin. The evidence is limited to preclinical in vitro and cell-based studies, without specific PubMed PMIDs. ## Historical & Cultural Context No traditional or historical medicinal uses of rhapontigenin are documented. It is primarily noted as a plant metabolite without reference to specific traditional systems. ## Synergistic Combinations Resveratrol, Quercetin, Curcumin, Green Tea Extract, Pterostilbene ## Frequently Asked Questions ### What foods contain rhapontigenin naturally? Rhapontigenin is primarily found in rhubarb (Rheum species), particularly in the roots and stems. It's also present in smaller amounts in certain grapes and berries, but rhubarb remains the richest dietary source of this stilbene compound. ### How does rhapontigenin compare to resveratrol? Both are stilbene compounds, but rhapontigenin shows stronger selective estrogen receptor β activity and more potent tyrosinase inhibition than resveratrol. Rhapontigenin appears more effective at inhibiting HIF-1α accumulation in cancer cells, while resveratrol has broader cardiovascular research support. ### What is the effective dosage of rhapontigenin for cancer prevention? No established human dosage exists as research is limited to cell studies using 10-50 μM concentrations. These laboratory concentrations don't translate directly to oral supplementation doses, and human clinical trials are needed to determine safe and effective dosing. ### Can rhapontigenin cause side effects? Specific side effects are unknown due to lack of human studies. However, its estrogenic activity suggests potential hormonal effects, and high doses may cause digestive upset similar to other rhubarb compounds. More research is needed to establish a comprehensive safety profile. ### Is rhapontigenin effective for skin lightening? Laboratory studies show rhapontigenin inhibits tyrosinase enzyme with IC50 values of 15-25 μM, suggesting potential melanin reduction effects. However, no human studies have tested topical or oral rhapontigenin for skin lightening, so clinical effectiveness remains unproven. ### Does rhapontigenin interact with cytochrome P450 medications? Rhapontigenin acts as a selective inactivator of cytochrome P450 1A1 (CYP1A1) at nanomolar concentrations, which may affect the metabolism of drugs metabolized by this enzyme. This interaction could potentially alter the effectiveness or blood levels of medications including certain cancer drugs, hormone therapies, and other compounds dependent on CYP1A1 metabolism. Individuals taking prescription medications should consult a healthcare provider before supplementing with rhapontigenin to assess potential drug-enzyme interactions. ### What does current research show about rhapontigenin's anti-cancer mechanisms? Preclinical studies demonstrate that rhapontigenin inhibits HIF-1α accumulation and angiogenesis in prostate cancer cells, suppresses breast cancer cell migration through the PI3K/Rac1 pathway, and shows activity against colorectal adenocarcinoma in laboratory settings. However, these findings are limited to cell-based and animal models, and human clinical trials are needed to confirm efficacy and safe dosing in cancer patients. Current evidence suggests rhapontigenin warrants further investigation but should not be considered a proven cancer treatment at this time. ### Who should avoid rhapontigenin supplementation? Individuals taking medications metabolized by cytochrome P450 1A1 (including certain chemotherapy agents, hormone-based therapies, and other pharmaceuticals) should avoid rhapontigenin without medical supervision due to potential enzyme inhibition. Pregnant and nursing women should exercise caution as safety data in these populations is limited, and those with existing liver conditions should consult a healthcare provider since rhapontigenin undergoes hepatic metabolism. People scheduled for surgery should discontinue rhapontigenin at least 2 weeks prior to avoid potential interactions with anesthetics and perioperative medications. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*