# Emetine (Psychotria ipecacuanha alkaloid)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/emetine-psychotria-ipecacuanha-alkaloid
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-02
**Evidence Score:** 1 / 10
**Category:** Compound
**Also Known As:** Psychotria ipecacuanha alkaloid, Cephaelis ipecacuanha alkaloid, Emetine dihydrochloride, (-)-Emetine, NSC 33669, Ipecac alkaloid

## Overview

Emetine (C₂₉H₄₀N₂O₄) is an isoquinoline alkaloid that inhibits eukaryotic protein synthesis by binding the 40S ribosomal subunit and suppresses multiple oncogenic signaling cascades including Wnt/β-catenin, PI3K/AKT, MAPK/ERK, and Hippo/YAP pathways. In preclinical gastric cancer models, emetine demonstrated IC₅₀ values of 0.0497 μM (MGC803 cells) and 0.0244 μM (HGC-27 cells), and exhibits sub-micromolar EC₅₀ activity against SARS-CoV-2, Zika, and Ebola viruses in high-throughput [antiviral](/ingredients/condition/immune-support) screens.

## Health Benefits

- **Antiamoebic and Antiparasitic Activity**: Emetine directly kills Entamoeba histolytica trophozoites by disrupting protein synthesis in the protozoan, and was the primary pharmacological treatment for invasive amoebiasis and amoebic liver abscess for much of the 20th century before safer alternatives emerged.
- **Anticancer Potential (Preclinical)**: In gastric cancer xenograft mouse models, emetine suppressed tumor growth, reduced Ki67 proliferation marker expression, and increased TUNEL-positive apoptotic cells at doses that produced no pathological changes in heart, liver, spleen, lung, or kidney tissue by HE staining.
- **[Antiviral](/ingredients/condition/immune-support) Broad-Spectrum Activity**: Emetine demonstrates sub-micromolar EC₅₀ potency against SARS-CoV-2, Zika virus, and Ebola virus in cell-based screens, attributed to its inhibition of host ribosomal machinery required for viral replication and direct interference with viral entry or replication factors.
- **Anti-inflammatory Signaling Suppression**: Emetine inhibits NF-κB activation with an IC₅₀ of approximately 0.31 μM by blocking IκBα phosphorylation, thereby reducing downstream production of [pro-inflammatory cytokine](/ingredients/condition/inflammation)s including TNF-α, IL-1β, and IL-6 in experimental models.
- **Emetic and Gastric Protective Reflex Induction**: As an irritant to gastric mucosa and a stimulant of the chemoreceptor trigger zone, emetine reliably induces vomiting and was a cornerstone of poison management protocols prior to the establishment of modern activated charcoal and gastric lavage techniques.
- **Pulmonary Hypertension Modulation (Experimental)**: Preclinical evidence indicates emetine attenuates pulmonary arterial hypertension through modulation of ERK1/2-Akt signaling and the Rho-kinase/cyclophilin-A/Basigin (CyPA/Bsg) axis, reducing vascular smooth muscle proliferation in experimental models.
- **Protein Synthesis Inhibition as Research Tool**: Emetine is widely employed in cell biology as a selective inhibitor of cytoplasmic 40S ribosomal subunit-dependent translation, making it a standard laboratory reagent for studying mRNA stability, translational regulation, and nonsense-mediated decay pathways.

## Mechanism of Action

Emetine exerts its primary pharmacological effects by intercalating with the 40S ribosomal subunit of eukaryotic ribosomes, physically blocking translocation of peptidyl-tRNA during elongation and thereby halting cytoplasmic protein synthesis; it concurrently disrupts [mitochondrial](/ingredients/condition/energy) protein synthesis and interferes with DNA and RNA polymerase activity. In cancer cell lines, emetine at 0.03 μM downregulates the Wnt/β-catenin pathway by modulating GSK-3β activity and reducing nuclear β-catenin, Axin2, LEF1, and Cyclin D1 expression, while simultaneously inhibiting MAPK/ERK phosphorylation and activating pro-apoptotic p38 and JNK kinases. Emetine also blocks PI3K/AKT signaling to suppress survival and proliferation, and inhibits Hippo/YAP pathway components to reduce transcriptional co-activator YAP-driven oncogenesis, collectively inducing cell cycle arrest, apoptosis, and suppression of migration and invasion. Its [anti-inflammatory](/ingredients/condition/inflammation) action proceeds through direct blockade of IκB kinase-mediated IκBα phosphorylation at IC₅₀ 0.31 μM, preventing NF-κB nuclear translocation and the transcription of TNF-α, IL-1β, and IL-6 genes.

## Clinical Summary

No modern randomized clinical trials have evaluated emetine for any indication using contemporary trial design standards; all quantified efficacy data originate from preclinical cell culture and animal model experiments. In mouse gastric cancer xenograft studies, emetine suppressed tumor growth and increased apoptotic indices without organ toxicity signals at effective doses, but translational relevance to humans remains unestablished. Historical clinical use for intestinal amoebiasis and amoebic liver abscess established proof-of-concept efficacy in uncontrolled observational settings, but emetine was subsequently displaced by metronidazole due to its narrow therapeutic window and serious cardiac side effect profile. Confidence in any therapeutic claim for emetine in human populations is low; the compound is best characterized as a potent pharmacological tool compound with promising but unvalidated translational potential.

## Nutritional Profile

Emetine is a pure bioactive alkaloid compound, not a nutritional ingredient, and therefore has no meaningful macronutrient, micronutrient, or dietary fiber profile. Its molecular formula is C₂₉H₄₀N₂O₄ (molecular weight 480.64 g/mol), and it is a member of the ipecacuanha alkaloid subclass of isoquinoline alkaloids. When present in crude ipecac root preparations, it co-occurs with cephaeline (differing structurally by a single hydroxyl group in place of a methoxy group), psychotrine, and methyl-psychotrine, with total alkaloid content in dried root ranging from 1.8–2.8% by weight. Bioavailability considerations include predicted high gastrointestinal absorption and blood-brain barrier penetration moderated by P-glycoprotein efflux transporter activity, with pharmacokinetic studies indicating preferential accumulation in lung tissue at concentrations exceeding [antiviral](/ingredients/condition/immune-support) EC₅₀ thresholds.

## Dosage & Preparation

- **Injectable Form (Historical Medical Use)**: Emetine dihydrochloride was administered intramuscularly at 1 mg/kg/day (maximum 60 mg/day) for up to 10 days for invasive amoebiasis; oral administration was avoided due to severe gastrointestinal intolerance and unreliable absorption.
- **Ipecac Syrup (Emetic Application)**: Standardized ipecac syrup containing approximately 21 mg of total alkaloids (emetine plus cephaeline) per 30 mL was the historical adult emetic dose; this preparation is no longer recommended by poison control authorities.
- **Research-Grade Emetine Dihydrochloride Hydrate**: Used in laboratory settings at nanomolar to low-micromolar concentrations (0.01–1 μM) for protein synthesis inhibition assays; not formulated for human consumption.
- **No Supplemental Form or Dose Exists**: Emetine is not commercially available as a dietary supplement, nutraceutical, or over-the-counter product; no safe supplemental dose range has been established in humans, and self-administration constitutes a significant toxicity risk.
- **Standardization Notes**: Pharmaceutical-grade ipecac root is standardized to contain 1.8–2.8% total alkaloids (combined emetine and cephaeline) by weight per historical pharmacopeial specifications.

## Safety & Drug Interactions

Emetine carries a serious [cardiovascular](/ingredients/condition/heart-health) toxicity profile, including dose-dependent cardiac arrhythmias, hypotension, electrocardiographic changes (T-wave inversion, QT prolongation), and myocarditis with repeated dosing, which historically required cardiac monitoring during therapeutic use and constitutes the primary reason it was replaced by safer antiparasitic agents. Gastrointestinal side effects including profound nausea, vomiting, diarrhea, and abdominal pain are nearly universal with oral exposure, and neuromuscular toxicity including muscle weakness and pain at injection sites is common with parenteral use. Emetine exhibits in vitro synergism with cisplatin in non-small cell lung cancer models, raising concern for additive toxicity if combined with platinum-based chemotherapy agents; interactions with other cardiotoxic drugs, QT-prolonging agents, and antiarrhythmics represent significant theoretical risks. Emetine is absolutely contraindicated in pregnancy (category X equivalent — documented embryotoxic and abortifacient potential in animal models), during lactation, in patients with cardiac disease, renal or hepatic impairment, and in pediatric or elderly populations; no safe maximum dose has been established for human supplemental use, and the compound should not be self-administered under any circumstances.

## Scientific Research

The evidence base for emetine is predominantly preclinical, consisting of in vitro cell-line studies and in vivo mouse xenograft or rodent disease models, with no modern randomized controlled trials reported in the peer-reviewed literature. High-throughput screening studies have confirmed sub-micromolar [antiviral](/ingredients/condition/immune-support) EC₅₀ values against SARS-CoV-2 and other RNA viruses, and MTT cytotoxicity assays in gastric cancer lines (MGC803, HGC-27) report IC₅₀ values below 0.05 μM, but these findings have not advanced to Phase I or Phase II human trials due to the compound's well-characterized cardiotoxicity. Historical clinical application of emetine for amoebiasis predates the modern randomized trial era and was conducted without placebo controls or standardized outcome reporting, meaning those therapeutic claims cannot be evaluated by contemporary evidence standards. Pharmacokinetic modeling supports favorable lung tissue distribution exceeding antiviral EC₅₀ thresholds, and synergism with cisplatin in non-small cell lung cancer cells has been documented in vitro, but all findings remain experimental and require human validation before clinical conclusions can be drawn.

## Historical & Cultural Context

Ipecac root, the botanical source of emetine, was used for centuries by indigenous peoples of Brazil — particularly the Mato Grosso region — as a treatment for dysentery, respiratory congestion, and as an emetic to expel ingested poisons, with the plant name deriving from the Tupi-Guaraní words meaning 'road-side sick-making plant.' Portuguese traders introduced ipecac to European medicine in the late 17th century, and by 1686 it gained formal recognition in France following its documented use to cure the Duke of Burgundy's dysentery, leading to widespread adoption across European pharmacopeias. Emetine was first isolated as a pure alkaloid in 1817 by Pelletier and Magendie, and throughout the 19th and early 20th centuries it remained the standard of care for hepatic amoebiasis and intestinal parasitic infections, featured prominently in military medicine during World War I and II for troops operating in endemic regions. Its displacement by metronidazole in the 1960s–1970s marked the decline of clinical emetine use, though renewed research interest in its anticancer and [antiviral](/ingredients/condition/immune-support) properties reflects a pattern of pharmacological rediscovery common to historically significant plant alkaloids.

## Synergistic Combinations

In non-small cell lung cancer cell-line studies, emetine combined with cisplatin demonstrated synergistic cytotoxicity beyond the additive effect of either agent alone, attributed to emetine's protein synthesis inhibition impairing DNA repair mechanisms that cancer cells rely on to recover from platinum-induced DNA crosslinks. Co-administration with cephaeline, the closely related ipecac alkaloid differing by a single hydroxyl group, may produce complementary inhibitory effects on overlapping and distinct molecular targets, though formal combination studies in human systems are lacking. No evidence-based synergistic nutritional supplement pairings exist for emetine, as it is not used in supplemental contexts; historical preparations simply delivered the full alkaloid fraction of ipecac root, providing a natural emetine-cephaeline combination.

## Frequently Asked Questions

### What is emetine and where does it come from?

Emetine is a natural isoquinoline alkaloid (C₂₉H₄₀N₂O₄) isolated from the dried roots of Psychotria ipecacuanha, a shrub native to the tropical rainforests of Brazil. It is one of two primary active alkaloids in ipecac root alongside cephaeline, and has been used in medicine since the 17th century for treating dysentery, inducing vomiting, and combating parasitic infections. Today it is primarily a research compound being investigated for anticancer and antiviral applications rather than a clinical or supplemental agent.

### Is emetine safe to take as a supplement?

Emetine is not available or approved as a dietary supplement and should not be self-administered; it carries serious toxicity risks including cardiac arrhythmias, myocarditis, QT prolongation, and profound gastrointestinal intolerance. No safe supplemental dose range has been established in humans, and its narrow therapeutic window led to its clinical replacement by safer drugs like metronidazole for amoebiasis. It is absolutely contraindicated in pregnancy, cardiac disease, and renal or hepatic impairment.

### How does emetine fight cancer in research studies?

In preclinical studies, emetine inhibits cancer cell growth by binding the 40S ribosomal subunit to block protein synthesis, while simultaneously downregulating Wnt/β-catenin, PI3K/AKT, MAPK/ERK, and Hippo/YAP signaling pathways that drive tumor proliferation and survival. IC₅₀ values of 0.0497 μM in MGC803 gastric cancer cells and 0.0244 μM in HGC-27 cells have been reported by MTT assay, and mouse xenograft studies showed tumor growth suppression with increased apoptosis without major organ toxicity. These findings are exclusively preclinical and have not been validated in human clinical trials.

### Does emetine have antiviral activity against COVID-19 or other viruses?

High-throughput screening studies have identified emetine as exhibiting sub-micromolar EC₅₀ activity against SARS-CoV-2, Zika virus, and Ebola virus in cell-based assays, with pharmacokinetic modeling suggesting that lung tissue concentrations achievable in preclinical models may exceed antiviral threshold concentrations. The proposed mechanism involves inhibition of host cell ribosomal machinery that viruses depend on for replication, as well as potential direct interference with viral entry or replication factors. No randomized controlled trials in humans have been conducted to validate these antiviral findings, and emetine is not approved or recommended for any antiviral indication.

### Why was emetine replaced by metronidazole for treating amoebiasis?

Emetine was the primary treatment for invasive amoebiasis and amoebic liver abscess throughout much of the 20th century but was replaced by metronidazole in the 1960s–1970s primarily because of its serious cardiovascular toxicity profile, including arrhythmias, electrocardiographic changes, and myocarditis requiring continuous cardiac monitoring during treatment. Metronidazole offers comparable antiparasitic efficacy with a substantially safer side effect profile and can be administered orally rather than requiring intramuscular injection. Emetine remains a second-line option in some treatment guidelines for cases refractory to metronidazole, but its clinical use is now rare in modern medicine.

### What is the current clinical research status of emetine as a cancer treatment?

Emetine remains in preclinical research stages, with most evidence limited to laboratory and animal models showing activity against gastric cancer and other malignancies through inhibition of protein synthesis. Clinical trials in human subjects are extremely limited, and emetine is not approved by regulatory agencies as an anticancer agent. Any potential therapeutic application would require extensive human safety and efficacy testing before clinical use could be considered.

### Are there any drug interactions between emetine and common medications?

Emetine may interact with medications that are sensitive to protein synthesis inhibition or that share hepatic metabolism pathways, though specific interaction data in humans is sparse due to limited modern clinical use. Because emetine has cardiotoxic potential and can cause electrolyte imbalances, concurrent use with cardiac glycosides (like digoxin) or medications affecting potassium levels should be approached cautiously. Consultation with a healthcare provider is essential before combining emetine with other substances, as interaction studies in contemporary medicine are minimal.

### Why is emetine no longer recommended for treating parasitic infections despite its effectiveness?

Emetine was discontinued for routine parasitic infection treatment primarily due to its narrow therapeutic window, cardiotoxicity (including arrhythmias and myocarditis), and systemic toxicity at therapeutic doses. Safer, more selective alternatives like metronidazole and other modern antiparasitic agents were developed with superior safety profiles and fewer side effects. The risk-benefit ratio shifted unfavorably toward emetine as newer pharmaceuticals became available, making it obsolete for standard clinical practice despite its historical significance in infectious disease treatment.

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