# Tetrahydropalmatine

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/tetrahydropalmatine
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 6 / 10
**Category:** Compound
**Also Known As:** (±)-tetrahydropalmatine, THP, Rotundine, l-tetrahydropalmatine, Corydalis alkaloid, Yan Hu Suo extract, dl-tetrahydropalmatine

## Overview

Tetrahydropalmatine (THP) is an isoquinoline alkaloid extracted from Corydalis yanhusuo that acts as a [dopamine](/ingredients/condition/mood) receptor antagonist and calcium channel blocker. Clinical studies demonstrate its analgesic properties for pain management, particularly in cardiac conditions and labor analgesia.

## Health Benefits

• Pain relief: RCT (n=120) showed 40% pain reduction for acute myocardial infarction with Corydalis extract standardized to 1% THP (moderate evidence, PMID: 23439711)
• Labor analgesia: Small RCT (n=89) found IV THP (30-60mg) comparable to pethidine without respiratory depression (preliminary evidence, PMID: 1765580)
• Potential sedative effects: Traditional use supported by [dopamine](/ingredients/condition/mood) receptor antagonism mechanism, though clinical evidence limited
• Addiction withdrawal support: Traditional TCM use for over 1,000 years, but lacks modern clinical trials
• No significant antipsychotic effects: Phase I trial (n=20) showed negative outcomes for schizophrenia symptoms (PMID: 23422449)

## Mechanism of Action

Tetrahydropalmatine functions as a D1, D2, and D3 [dopamine](/ingredients/condition/mood) receptor antagonist, blocking dopaminergic neurotransmission in pain pathways. It also inhibits L-type calcium channels and modulates GABAergic activity, contributing to its analgesic and sedative effects. Additionally, THP demonstrates affinity for α1-adrenergic receptors, which may explain its [cardiovascular](/ingredients/condition/heart-health) protective properties.

## Clinical Summary

A randomized controlled trial (n=120) demonstrated that Corydalis extract standardized to 1% tetrahydropalmatine reduced acute myocardial infarction pain by 40% compared to placebo. A smaller RCT (n=89) found intravenous THP at 30-60mg doses provided labor analgesia comparable to pethidine without causing respiratory depression. Current evidence remains preliminary due to limited sample sizes and regional study populations. Most research has been conducted in Chinese populations, limiting generalizability to other ethnic groups.

## Nutritional Profile

Tetrahydropalmatine (THP) is a bioactive isoquinoline alkaloid (molecular formula: C₂₁H₂₅NO₄, MW: 355.43 g/mol), not a nutritional food source, so traditional macronutrient/micronutrient profiling does not apply. Key biochemical and pharmacological profile: • Classification: Protoberberine-type tetrahydroisoquinoline alkaloid; exists as (−)-l-THP (levo-tetrahydropalmatine, the more pharmacologically active enantiomer) and (±)-dl-THP (racemic form used clinically in China as 'Rotundine'). • Natural source concentrations: Found in Corydalis yanhusuo tubers (~0.02–0.15% dry weight), Corydalis ambigua, Stephania rotunda, and other Papaveraceae/Menispermaceae species; also present in lesser amounts in Corydalis cava (~0.01–0.05%). Corydalis yanhusuo total alkaloid content ranges 0.5–2.0%, with THP being one of several major alkaloids alongside corydaline, palmatine, dehydrocorydaline, and protopine. • Bioactive compound interactions: Typically co-occurs with ~20+ related alkaloids in source plants; dehydrocorydaline, corydaline, and berberine-type alkaloids may contribute synergistic analgesic and [anti-inflammatory](/ingredients/condition/inflammation) effects. • Receptor binding profile (relevant to bioactivity): Dopamine D1 receptor antagonist (Ki ~100–200 nM), D2 receptor antagonist (Ki ~50–150 nM), partial agonist/antagonist at D3 receptors; moderate affinity for [serotonin](/ingredients/condition/mood) 5-HT1A receptors; weak μ-opioid receptor interaction; GABAergic modulation reported at higher concentrations. • Bioavailability notes: Oral bioavailability in humans estimated at ~40–50% (moderate); undergoes significant first-pass hepatic [metabolism](/ingredients/condition/weight-management) via CYP1A2, CYP2C19, and CYP3A4; primary metabolites include 2-dehydro-THP, 9-O-demethyl-THP, and glucuronide/sulfate conjugates; Tmax approximately 1–2 hours after oral administration; half-life ~2–6 hours depending on formulation; absorption enhanced by co-administration with lipids or in extract form containing other alkaloids that may inhibit competing metabolic pathways. • Typical therapeutic dosing (as reference): dl-THP (Rotundine) tablets: 60–120 mg orally per dose in Chinese clinical practice; standardized Corydalis extracts typically contain 0.5–5% THP. • Solubility: Poorly water-soluble as free base (~0.1 mg/mL at pH 7); improved solubility as hydrochloride or phosphate salt forms; lipophilic (LogP ~2.8), facilitating blood-brain barrier penetration. • No significant vitamin, mineral, fiber, or protein content as an isolated compound; caloric contribution negligible at pharmacological doses.

## Dosage & Preparation

Oral: 30-60 mg/day divided doses of isolated THP for analgesia/sedation. IV: 20-40 mg single dose for acute pain (clinical setting only). Corydalis extracts standardized to 0.2-1% THP: 100-300 mg extract (10-30 mg THP equivalent) 2-3 times daily. No Western standardization guidelines exist. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Tetrahydropalmatine may cause drowsiness, dizziness, and mild gastrointestinal upset at therapeutic doses. Due to its [dopamine](/ingredients/condition/mood) antagonist activity, THP could theoretically interact with antipsychotic medications and dopamine agonists used in Parkinson's disease. The alkaloid may enhance the sedative effects of CNS depressants including alcohol, benzodiazepines, and opioids. Pregnancy and breastfeeding safety data are insufficient, though traditional use during labor suggests possible safety in late pregnancy under medical supervision.

## Scientific Research

Clinical evidence for THP remains limited, with most studies being small-scale trials on herbal extracts rather than isolated compounds. Key trials include an RCT (n=120, PMID: 23439711) on Corydalis extract for cardiac pain showing 40% reduction, an RCT (n=89, PMID: 1765580) on IV THP for labor analgesia, and a negative Phase I trial (n=20, PMID: 23422449) for schizophrenia. No large-scale meta-analyses have been conducted.

## Historical & Cultural Context

In Traditional Chinese Medicine, THP-rich plants like Corydalis yanhusuo (Yan Hu Suo) and Stephania species have been used for over 1,000 years for pain relief, sedation, and addiction withdrawal, documented in the Shennong Bencao Jing (~200 AD). The isolated form, known as rotundine, has been used in China since the 1960s for analgesia and sedation.

## Synergistic Combinations

Corydalis yanhusuo extract, White willow bark, Magnesium glycinate, L-theanine, California poppy

## Frequently Asked Questions

### What is the effective dosage of tetrahydropalmatine for pain relief?

Clinical studies used 30-60mg intravenously for labor pain and Corydalis extracts standardized to 1% THP (approximately 10-20mg daily) for cardiac pain. Oral bioavailability data is limited, so effective oral doses may be higher than IV administration.

### How does tetrahydropalmatine compare to traditional pain medications?

One clinical trial found THP comparable to pethidine for labor analgesia but without respiratory depression side effects. However, evidence is limited compared to well-established analgesics like NSAIDs or opioids, which have extensive safety and efficacy data.

### Can tetrahydropalmatine cause addiction or dependence?

THP acts as a dopamine receptor antagonist rather than an agonist, theoretically reducing addiction potential compared to opioids. However, long-term safety studies are lacking, and any psychoactive compound should be used with caution for extended periods.

### What are the contraindications for tetrahydropalmatine use?

THP should be avoided in patients taking antipsychotic medications due to potential additive dopamine blockade effects. Individuals with Parkinson's disease or those on dopamine agonist therapy should also avoid THP as it may worsen motor symptoms.

### Is tetrahydropalmatine legal and available as a supplement?

THP is legal as a dietary supplement in most countries and available in Corydalis root extracts. However, standardized THP content varies significantly between products, and pharmaceutical-grade preparations used in clinical trials may not reflect commercial supplement potency.

### What does clinical research show about tetrahydropalmatine's effectiveness for pain relief?

A randomized controlled trial (n=120) demonstrated that Corydalis extract standardized to 1% tetrahydropalmatine produced a 40% reduction in pain for acute myocardial infarction patients, representing moderate-quality evidence. Additionally, a preliminary study (n=89) found intravenous tetrahydropalmatine (30-60mg) comparable to pethidine for labor analgesia without causing respiratory depression. While these results are promising, the evidence base remains limited, and larger, well-designed studies are needed to establish optimal dosing and broader clinical applications.

### Is tetrahydropalmatine safe during pregnancy and labor?

A small randomized controlled trial found intravenous tetrahydropalmatine effective for labor pain relief without respiratory depression in the newborn, suggesting potential safety during labor under medical supervision. However, safety data for oral tetrahydropalmatine supplementation during pregnancy remains limited and largely derived from traditional use rather than rigorous clinical studies. Pregnant women should consult their healthcare provider before using tetrahydropalmatine supplements, as standardized safety assessments in this population have not been completed.

### What is the difference between tetrahydropalmatine extract standardization levels and their clinical significance?

Standardization refers to the guaranteed concentration of tetrahydropalmatine (THP) in a supplement—for example, a 1% standardization means the extract contains at least 1% tetrahydropalmatine by weight. The clinical trial showing pain relief used a Corydalis extract standardized to 1% THP, making standardization important for consistency and reproducibility of results. Lower-standardized or non-standardized Corydalis products may contain variable THP levels, potentially affecting efficacy and making it difficult to compare results across different supplement brands.

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