# Rhynchophylline **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/rhynchophylline **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-03-28 **Evidence Score:** 2 / 10 **Category:** Compound **Also Known As:** Uncaria rhynchophylla alkaloid, Cat's claw alkaloid, Gou teng alkaloid, Hook vine alkaloid, Rhynchophylline alkaloid, C₂₂H₂₈N₂O₄ ## Overview Rhynchophylline is a tetracyclic oxindole alkaloid derived primarily from Uncaria rhynchophylla (cat's claw hook), a plant used in traditional Chinese medicine. It is studied for its interactions with NMDA receptors and calcium channel modulation, though robust human clinical evidence remains limited. ## Health Benefits • No clinical health benefits can be verified from the provided research • The research contains only chemical property data without pharmacological studies • No human trials or health outcome data were included in the research • No evidence quality can be assessed from chemical supplier databases alone • Clinical research literature would be needed to establish health benefits ## Mechanism of Action Rhynchophylline acts as a non-competitive antagonist at NMDA (N-methyl-D-aspartate) receptors, inhibiting excessive calcium influx triggered by glutamate excitotoxicity. It also blocks voltage-dependent calcium channels (L-type and N-type), reducing intracellular Ca²⁺ overload in neuronal and smooth muscle cells. Additionally, preclinical data suggest it may inhibit platelet aggregation by suppressing thromboxane A2 synthesis and modulating 5-HT2A [serotonin](/ingredients/condition/mood) receptor activity. ## Clinical Summary Human clinical trials specifically isolating rhynchophylline as a single compound are largely absent from the published literature as of 2024. Most evidence comes from in vitro cell studies and rodent models examining neuroprotection, antihypertensive effects, and anti-aggregation properties, making direct translation to human dosing unreliable. Some research involves whole Uncaria rhynchophylla extracts rather than isolated rhynchophylline, confounding attribution of effects to this specific alkaloid. Overall, evidence quality is preclinical and insufficient to establish verified therapeutic benefits in humans. ## Nutritional Profile Rhynchophylline is not a nutrient or food substance; it is a tetracyclic oxindole alkaloid (molecular formula: C₂₂H₂₈N₂O₄; molecular weight: 384.47 g/mol) found primarily in Uncaria rhynchophylla (Gou Teng / Cat's Claw). It is a bioactive secondary plant metabolite, not a source of macronutrients, vitamins, or minerals. Typical concentrations in Uncaria species range from approximately 0.02–0.5% dry weight of the hook-bearing stems, though this varies significantly by species, harvest time, and plant part. It is one of several oxindole alkaloids present alongside isorhynchophylline, corynoxeine, and hirsutine. As a lipophilic alkaloid, it has moderate oral bioavailability; in vitro and animal pharmacokinetic studies suggest it can cross the blood-brain barrier to some degree due to its relatively low molecular weight and moderate lipophilicity (LogP ~2.3). It is not consumed in isolated purified form as a dietary supplement but is ingested as part of traditional herbal preparations (e.g., Uncaria hook decoctions in Traditional Chinese Medicine). No macronutrient, fiber, protein, vitamin, or mineral content is attributable to this single compound. Bioavailability in humans has not been rigorously characterized in published clinical pharmacokinetic trials; animal data suggest hepatic first-pass [metabolism](/ingredients/condition/weight-management) via cytochrome P450 enzymes (particularly CYP3A4) may limit systemic exposure. The compound itself serves no nutritional function and should be characterized solely as a pharmacologically active phytochemical alkaloid. ## Dosage & Preparation No clinically studied dosage ranges were provided in the research. The available data contains only chemical properties without any dosing protocols or clinical usage information. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions Rhynchophylline's safety profile in humans has not been systematically evaluated in controlled trials, meaning no established safe dosage range exists for supplemental use. Due to its NMDA receptor antagonism and calcium channel blocking activity, theoretical interactions exist with antihypertensive medications, NMDA-targeting drugs such as memantine, and anticoagulants or antiplatelet agents like warfarin or aspirin. Pregnancy and lactation safety is unknown, and use should be avoided without medical supervision given the absence of reproductive toxicity data. Individuals with hypotension, bleeding disorders, or those taking CNS-active medications should exercise particular caution. ## Scientific Research No clinical trials, RCTs, or meta-analyses were found in the provided research. The available data consists solely of chemical and physical properties from supplier databases without any PMIDs or peer-reviewed pharmacological studies. ## Historical & Cultural Context No traditional or historical use information was included in the provided research. The data focuses exclusively on chemical properties without ethnobotanical or traditional medicine context. ## Synergistic Combinations Cannot be determined from available chemical property data ## Frequently Asked Questions ### What is rhynchophylline and where does it come from? Rhynchophylline is a tetracyclic oxindole alkaloid concentrated in the hooked stems of Uncaria rhynchophylla, a plant used in Traditional Chinese Medicine under the name Gou Teng. It is one of several bioactive alkaloids in the Uncaria genus, alongside isorhynchophylline and corynoxeine, and is typically extracted via solvent isolation from dried plant material. ### Does rhynchophylline have any proven effects on the brain? Preclinical studies in rodents and cell cultures suggest rhynchophylline may offer neuroprotective effects by blocking NMDA receptors and reducing glutamate-induced excitotoxicity, a mechanism relevant to conditions like stroke and neurodegeneration. However, no human clinical trials have confirmed these findings, so neuroprotective benefits in people cannot be verified at this time. ### Can rhynchophylline lower blood pressure? Animal studies have shown that rhynchophylline may reduce blood pressure by blocking L-type voltage-gated calcium channels in vascular smooth muscle, a mechanism similar to dihydropyridine calcium channel blockers like amlodipine. These findings come exclusively from rodent models and in vitro assays; no human trials have established an antihypertensive dose or confirmed this effect in people. ### Is rhynchophylline safe to take as a supplement? No established safe dosing range for isolated rhynchophylline supplementation has been determined through human clinical research. Because it interacts with NMDA receptors and calcium channels, it carries theoretical risks of potentiating antihypertensive drugs, anticoagulants, and CNS depressants. Individuals with cardiovascular conditions, bleeding disorders, or who are pregnant should avoid it without explicit guidance from a healthcare provider. ### How is rhynchophylline different from isorhynchophylline? Rhynchophylline and isorhynchophylline are stereoisomers sharing the same tetracyclic oxindole core structure but differing in spatial configuration at the C-7 and C-20 positions of the molecule. Both are found in Uncaria species and share overlapping pharmacological activities including NMDA antagonism, though some studies suggest isorhynchophylline may exhibit slightly different potency profiles at specific receptor subtypes. Distinguishing their individual contributions in whole-plant extracts remains an active area of preclinical research. ### What is the current state of clinical research on rhynchophylline's health effects? Current clinical research on rhynchophylline is limited, with most available data consisting of chemical property information rather than human pharmacological studies or health outcome trials. To establish verified health benefits, peer-reviewed clinical research involving human participants would be necessary to move beyond preliminary chemical characterization. Consumers should be aware that chemical supplier databases alone cannot provide evidence of therapeutic efficacy or safety in human use. ### Does rhynchophylline have any documented food sources, or is it only available as a supplement? Rhynchophylline is a bioactive alkaloid found naturally in Uncaria plants, particularly Uncaria tomentosa (cat's claw) and Uncaria rhynchophylla, making these plant sources the primary way to obtain it through diet. However, the concentration of rhynchophylline in these plant materials varies significantly based on growing conditions and plant part used, making supplemental extracts the more standardized option for consistent dosing. Whole plant consumption of Uncaria species is not a common dietary practice in most Western diets. ### Are there different extraction methods or forms of rhynchophylline supplements, and do they differ in quality? Rhynchophylline supplements are typically derived from standardized plant extracts of Uncaria species, with varying extraction methods affecting the final alkaloid concentration and purity profile. Different suppliers may use distinct extraction techniques that influence the ratio of rhynchophylline to other alkaloids present, though without established clinical standards, it is difficult to determine which form is most effective. Third-party testing for alkaloid content can help consumers compare product quality across different brands and formulations. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*