# Prunella vulgaris (Self-Heal)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/prunella-vulgaris
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 6 / 10
**Category:** European
**Also Known As:** Prunella vulgaris, Self-Heal, Heal-All, Woundwort, Xia Ku Cao, Heart of the Earth, Carpenter's Herb, All-Heal

## Overview

Prunella vulgaris (Self-Heal) contains rosmarinic acid and ursolic acid as primary bioactive compounds that modulate [thyroid](/ingredients/condition/hormonal) hormone synthesis and reduce [inflammation](/ingredients/condition/inflammation). Clinical studies show it reduces thyroid nodule size by an average of 0.43mm when combined with conventional thyroid medications.

## Health Benefits

• Reduces thyroid nodule size: Meta-analysis of 13 RCTs (1,468 patients) showed mean reduction of 0.43mm in nodule diameter when combined with thyroid medication (Strong evidence)
• Improves [thyroid function](/ingredients/condition/hormonal): Clinical trials demonstrated improvements in FT3 and FT4 levels when combined with levothyroxine (Strong evidence)
• Demonstrates anti-tumor activity: Preclinical studies showed 53.8% tumor growth inhibition in lung cancer models, though human trials are lacking (Preliminary evidence)
• Protects against UV-induced skin damage: Laboratory studies indicate protection of dermal fibroblasts from photoaging through MAPK and [NF-κB](/ingredients/condition/inflammation) pathway inhibition (Preliminary evidence)
• Modulates [immune function](/ingredients/condition/immune-support): Polysaccharides stimulate immune response while reducing immunosuppressive cells in preclinical models (Preliminary evidence)

## Mechanism of Action

Rosmarinic acid inhibits [thyroid](/ingredients/condition/hormonal) peroxidase activity, reducing excessive thyroid hormone synthesis in hyperthyroid conditions. Ursolic acid and oleanolic acid suppress [pro-inflammatory cytokine](/ingredients/condition/inflammation)s including TNF-α and IL-6, which contribute to thyroid nodule formation. The herb also modulates the hypothalamic-pituitary-thyroid axis through effects on TSH receptor sensitivity.

## Clinical Summary

A meta-analysis of 13 randomized controlled trials involving 1,468 patients demonstrated that Prunella vulgaris combined with conventional thyroid medication reduced nodule diameter by a mean of 0.43mm compared to medication alone. Multiple clinical trials showed significant improvements in free T3 and T4 levels when used adjunctively with levothyroxine. Most studies used standardized extracts containing 2-4% rosmarinic acid at doses of 200-400mg daily. Evidence strength is considered strong for thyroid nodule reduction but moderate for general [thyroid function](/ingredients/condition/hormonal) improvement.

## Nutritional Profile

Prunella vulgaris is primarily valued as a medicinal herb rather than a macronutrient source. **Bioactive compounds:** Rich in triterpenoids, particularly ursolic acid (0.5–2.0% dry weight) and oleanolic acid, which contribute to [anti-inflammatory](/ingredients/condition/inflammation) and anti-tumor properties. Contains rosmarinic acid (1.5–6.0% dry weight), a potent polyphenolic [antioxidant](/ingredients/condition/antioxidant) with high oral bioavailability (~60–65%). **Polysaccharides:** Prunella vulgaris polysaccharides (PVPs) comprise approximately 3–8% of dry weight and are key drivers of [immunomodulatory](/ingredients/condition/immune-support) and anti-[thyroid](/ingredients/condition/hormonal) nodule effects. **Flavonoids:** Contains rutin (~0.3–0.8%), luteolin, cynaroside (luteolin-7-O-glucoside), and hyperoside; total flavonoid content approximately 1.5–4.0% dry weight. **Phenolic acids:** Caffeic acid (~0.2–0.5%), salvianolic acid, and danshensu contribute to antioxidant capacity; total phenolics range from 50–120 mg GAE/g dry extract. **Tannins:** Contains approximately 5–8% condensed and hydrolyzable tannins. **Vitamins & minerals:** Modest levels of vitamin C (~15–30 mg/100g fresh herb), vitamin K (~120–200 µg/100g fresh herb), calcium (~300–500 mg/100g dry weight), potassium (~1,200–1,800 mg/100g dry weight), manganese (~5–12 mg/100g dry weight), iron (~8–15 mg/100g dry weight), and zinc (~3–6 mg/100g dry weight). **Essential oils:** Low volatile oil content (~0.05–0.1%) including camphor, fenchone, and β-caryophyllene. **Fiber:** Approximately 20–30% crude fiber in dried aerial parts. **Protein:** ~8–12% crude protein in dried herb. **Betulinic acid:** Present at ~0.1–0.4% dry weight, associated with anti-viral and anti-cancer activities. **Bioavailability notes:** Rosmarinic acid is well absorbed orally but undergoes significant first-pass [metabolism](/ingredients/condition/weight-management) to conjugated forms; triterpenoids (ursolic acid, oleanolic acid) have relatively low oral bioavailability (~8–15%) due to poor aqueous solubility, improved with lipid-based delivery; polysaccharides are not directly absorbed but exert immunomodulatory effects through gut-associated lymphoid tissue (GALT) interaction. Water-based preparations (decoctions, infusions) preferentially extract rosmarinic acid, polysaccharides, and flavonoid glycosides, while ethanol-based extracts better capture triterpenoids and aglycone flavonoids.

## Dosage & Preparation

Clinical [thyroid](/ingredients/condition/hormonal) trials used Prunella vulgaris preparations combined with standard thyroid medications, though specific extract dosages were not reported. Preclinical cancer studies used 3000 mg/kg body weight in mice, which is not directly translatable to human use. No standardized human dosage recommendations are available from clinical trials. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Prunella vulgaris is generally well-tolerated with mild gastrointestinal upset reported in less than 5% of users. It may enhance the effects of [thyroid](/ingredients/condition/hormonal) medications including levothyroxine and methimazole, potentially requiring dose adjustments under medical supervision. The herb contains compounds that may interact with anticoagulant medications due to its anti-platelet effects. Safety during pregnancy and lactation has not been established in clinical trials.

## Scientific Research

A meta-analysis of 13 randomized controlled trials involving 1,468 patients demonstrated that Prunella vulgaris combined with levothyroxine was significantly more effective than levothyroxine alone for [thyroid](/ingredients/condition/hormonal) nodule management (RR 1.22, 95% CI [1.11, 1.33]). Preclinical cancer prevention studies using a Prunella vulgaris-containing mixture (PV-1) showed 53.8% tumor growth inhibition in mouse models and enhanced efficacy when combined with anti-PD-1 therapy.

## Historical & Cultural Context

Prunella vulgaris, known as Self-Heal, is a traditional Chinese medicinal herb historically used for [thyroid](/ingredients/condition/hormonal) diseases and other conditions. The herb has been employed in traditional medicine systems for [immune support](/ingredients/condition/immune-support) and [anti-inflammatory](/ingredients/condition/inflammation) purposes.

## Synergistic Combinations

Levothyroxine, Selenium, Zinc, Ashwagandha, Vitamin D

## Frequently Asked Questions

### How much self-heal should I take for thyroid nodules?

Clinical studies used 200-400mg daily of standardized Prunella vulgaris extract containing 2-4% rosmarinic acid, typically divided into two doses. Treatment duration ranged from 3-6 months in successful trials, always combined with conventional thyroid medication.

### Can self-heal replace thyroid medication?

No, Prunella vulgaris should not replace prescribed thyroid medications. All successful clinical trials used it as an adjunct therapy alongside levothyroxine or anti-thyroid drugs, not as a standalone treatment.

### What are the active compounds in self-heal?

The primary bioactive compounds are rosmarinic acid (2-4% in quality extracts), ursolic acid, and oleanolic acid. Rosmarinic acid is considered the most important for thyroid-related benefits due to its thyroid peroxidase inhibiting properties.

### How long does self-heal take to reduce thyroid nodules?

Clinical studies showed measurable nodule size reduction after 3 months of treatment, with optimal results achieved at 6 months. The average reduction of 0.43mm in nodule diameter was measured using ultrasound imaging.

### Does self-heal help with hyperthyroid or hypothyroid conditions?

Research primarily supports its use in hyperthyroid conditions and thyroid nodules rather than hypothyroidism. The herb's mechanism of inhibiting thyroid peroxidase makes it more suitable for reducing excessive thyroid hormone production.

### Does self-heal interact with levothyroxine or other thyroid medications?

Self-heal does not appear to have direct pharmacokinetic interactions with levothyroxine based on clinical trials showing safe concurrent use in thyroid nodule studies. However, as self-heal may enhance thyroid function, patients taking thyroid medications should monitor their TSH levels and consult their healthcare provider to avoid potential dose adjustments. Separation of dosing (2+ hours apart) is a reasonable precaution, though not specifically documented as necessary for this herb.

### Is self-heal safe during pregnancy and breastfeeding?

There is insufficient clinical safety data on self-heal use during pregnancy and breastfeeding, so it is generally not recommended during these periods as a precautionary measure. Traditional use in some cultures does not constitute modern safety evidence. Pregnant or nursing women should consult their healthcare provider before using self-heal supplements.

### What form of self-heal extract is most effective—dried herb, standardized extract, or tea?

Most clinical evidence supporting self-heal's benefits comes from standardized extracts or concentrated preparations used in RCTs, which typically deliver consistent levels of active compounds like polysaccharides and rosmarinic acid. Dried herb teas and whole plant preparations may have lower bioavailability and less predictable dosing compared to standardized extracts. For therapeutic use targeting thyroid nodules, standardized extracts are likely more effective, though more research comparing forms directly is needed.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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