# Selfheal (Prunella vulgaris)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/selfheal
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-30
**Evidence Score:** 2 / 10
**Category:** European
**Also Known As:** Prunella vulgaris, Self-heal, Heal-all, Xia Ku Cao, All-heal, Woundwort, Heart-of-the-earth, Blue curls, Carpenter's herb, Slough-heal, Brunelle commune

## Overview

Selfheal (Prunella vulgaris) is a European medicinal herb whose primary bioactive compounds — rosmarinic acid and ursolic acid — exert antioxidant, [anti-inflammatory](/ingredients/condition/inflammation), and [immunomodulatory](/ingredients/condition/immune-support) effects. It is most studied for [thyroid](/ingredients/condition/hormonal) disease support, where it appears to regulate TSH, FT3, and FT4 levels by modulating autoimmune activity and [oxidative stress](/ingredients/condition/antioxidant) in thyroid tissue.

## Health Benefits

• May improve thyroid disease outcomes when combined with levothyroxine, as part of a meta-analysis of 13 RCTs (n=1468 patients).[10]
• In combination with antithyroid drugs, it shows improvements in [thyroid function](/ingredients/condition/hormonal) markers like FT3, FT4, and TSH.[3]
• Reduces tumor immune microenvironment by inhibiting granulocytic myeloid-derived suppressor cells, based on preclinical studies.[1][2]
• Enhances T-cell function and boosts splenocyte proliferation in aging models, supported by preclinical research.[4]
• Exhibits [antimicrobial](/ingredients/condition/immune-support) and [anti-inflammatory](/ingredients/condition/inflammation) properties, traditionally recognized in herbal medicine.[7]

## Mechanism of Action

Rosmarinic acid in Prunella vulgaris inhibits NF-κB signaling, reducing [pro-inflammatory cytokine](/ingredients/condition/inflammation) production (IL-6, TNF-α) and [oxidative stress](/ingredients/condition/antioxidant) in [thyroid](/ingredients/condition/hormonal) tissue, which may explain its benefits in autoimmune thyroid conditions. Ursolic acid modulates T-cell activity and suppresses regulatory T-cell (Treg) pathways within the tumor immune microenvironment, limiting immunosuppression that tumors exploit. Additionally, polysaccharides from Prunella vulgaris have been shown to inhibit viral replication by blocking gp120-CD4 interactions, relevant to its [antiviral](/ingredients/condition/immune-support) traditional uses.

## Clinical Summary

A meta-analysis of 13 randomized controlled trials (n=1,468 patients) found that Prunella vulgaris combined with levothyroxine significantly improved [thyroid function](/ingredients/condition/hormonal) outcomes compared to levothyroxine alone, including reductions in thyroid antibody titers. Separate RCT-level evidence demonstrates that its combination with antithyroid drugs improves FT3, FT4, and TSH normalization in hyperthyroid patients. Evidence for its role in tumor immune microenvironment modulation is primarily preclinical, limiting conclusions about anti-cancer applications in humans. Overall, the thyroid-related evidence is the strongest, though study heterogeneity and small individual trial sizes mean findings should be interpreted cautiously.

## Nutritional Profile

Selfheal (Prunella vulgaris) is a herbaceous plant with a documented phytochemical profile rather than a conventional macronutrient-focused nutritional profile. Key bioactive compounds include: rosmarinic acid (primary polyphenol, approximately 15–30 mg/g dry weight in aerial parts, high bioavailability via intestinal absorption), ursolic acid (pentacyclic triterpene, ~2–5 mg/g dry weight), oleanolic acid (~1–3 mg/g dry weight), and betulinic acid in smaller amounts. Flavonoids include rutin (~3–8 mg/g dry weight), hyperoside, luteolin, apigenin, and kaempferol glycosides. The plant contains caffeic acid derivatives and other hydroxycinnamic acids contributing to its [antioxidant](/ingredients/condition/antioxidant) capacity (DPPH IC50 reported ~10–50 µg/mL in ethanolic extracts). Polysaccharides (prunellins) are present at approximately 5–15% of dry weight and contribute to [immunomodulatory](/ingredients/condition/immune-support) activity. Tannins (hydrolysable and condensed) are estimated at 2–6% dry weight. Essential oil constituents include camphor, fenchone, and caryophyllene in trace amounts (<0.5% dry weight). Mineral content includes potassium (~300–500 mg/100g fresh weight), calcium (~100–200 mg/100g), magnesium (~30–60 mg/100g), and iron (~2–4 mg/100g), based on comparable Lamiaceae species analyses. Vitamin C has been detected (~20–40 mg/100g fresh weight) and beta-carotene is present in modest amounts (~0.5–1.5 mg/100g). Crude fiber content is approximately 15–25% of dry weight. Protein content is relatively low at ~8–12% dry weight. Bioavailability note: Rosmarinic acid demonstrates good oral bioavailability (~30–50% absorption in humans); polysaccharide fractions require aqueous extraction to achieve biologically relevant concentrations; triterpene acids have limited oral bioavailability (<10%) without lipid-based delivery systems.

## Dosage & Preparation

Clinically studied dosages are from combination therapies with anti[thyroid](/ingredients/condition/hormonal) drugs, without specific standardization details. In preclinical studies, Prunella vulgaris-containing mixtures were used at 3000 mg/kg body weight in mice. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Prunella vulgaris is generally well tolerated at typical dietary and supplemental doses, with no serious adverse events reported in clinical trials reviewed to date. Because it may alter [thyroid](/ingredients/condition/hormonal) hormone levels (TSH, FT3, FT4), caution is warranted in patients on levothyroxine, methimazole, or other thyroid medications, as dosage adjustments may be needed. Its [immunomodulatory](/ingredients/condition/immune-support) activity could theoretically interact with immunosuppressant drugs (e.g., cyclosporine, corticosteroids), though direct human interaction data are lacking. Safety in pregnancy and lactation has not been established in clinical studies, and use during these periods should be avoided without medical supervision.

## Scientific Research

There are no human RCTs or clinical trials on Prunella vulgaris alone. Evidence is limited to preclinical studies and combination therapies with anti[thyroid](/ingredients/condition/hormonal) drugs. A meta-analysis showed improved outcomes in thyroid disease when Prunella vulgaris is combined with levothyroxine, but specific PMIDs were not detailed.

## Historical & Cultural Context

Prunella vulgaris has been used in Traditional Chinese Medicine as 'Xia Ku Cao' for clearing heat, detoxifying, and treating swellings and [thyroid](/ingredients/condition/hormonal) issues. In European herbalism, it is known as 'selfheal' and is used for wound healing.

## Synergistic Combinations

Levothyroxine, methimazole, rosmarinic acid, luteolin, ursolic acid

## Frequently Asked Questions

### Can selfheal help with thyroid disease?

Yes, clinical evidence from a meta-analysis of 13 RCTs (n=1,468) suggests Prunella vulgaris combined with levothyroxine improves thyroid function markers more effectively than levothyroxine alone. It also shows benefit alongside antithyroid drugs in hyperthyroid patients by helping normalize FT3, FT4, and TSH levels, likely through reducing thyroid autoantibodies and oxidative stress in thyroid tissue.

### What are the active compounds in Prunella vulgaris?

The primary bioactive compounds in Prunella vulgaris are rosmarinic acid, ursolic acid, oleanolic acid, and high-molecular-weight polysaccharides. Rosmarinic acid is responsible for much of its anti-inflammatory and antioxidant activity via NF-κB inhibition, while ursolic acid contributes to its immunomodulatory and potential anti-tumor effects.

### Does selfheal interact with thyroid medications?

Prunella vulgaris can alter thyroid hormone levels — specifically TSH, FT3, and FT4 — which means it may potentiate or interfere with levothyroxine and antithyroid drugs like methimazole or propylthiouracil. Patients on thyroid medication should consult a physician before supplementing, as dosage recalibration may be necessary to avoid over- or under-treatment of their condition.

### What is the typical dose of selfheal extract used in studies?

Clinical trials investigating Prunella vulgaris for thyroid conditions have typically used it as a standardized herbal formula (often as part of Traditional Chinese Medicine preparations) rather than isolated extract, making a precise universal dosage difficult to define. Preclinical studies commonly use rosmarinic acid concentrations of 10–50 mg/kg in animal models, but equivalent validated human dosing guidelines have not yet been established by regulatory bodies.

### Is selfheal effective against viruses?

Prunella vulgaris polysaccharides have demonstrated antiviral activity in laboratory studies by blocking the HIV gp120-CD4 binding interaction, and separate in vitro work shows activity against herpes simplex virus (HSV-1 and HSV-2). However, these findings are based on cell-culture and animal studies; no large human clinical trials have confirmed antiviral efficacy in vivo, so it should not replace evidence-based antiviral treatments.

### Is selfheal safe to take during pregnancy or while breastfeeding?

There is limited clinical safety data on selfheal use during pregnancy and lactation, so it is generally recommended to avoid supplementation during these periods unless under direct medical supervision. Traditional use in some cultures suggests a history of safety, but controlled studies in pregnant or nursing women are lacking. Consult with a healthcare provider before using selfheal if you are pregnant or breastfeeding.

### What is the difference between selfheal extract, tea, and dried herb forms?

Selfheal extract (standardized liquid or powder) typically offers concentrated bioactive compounds with consistent dosing, while tea and dried herb forms vary in potency depending on preparation method and plant quality. Extracts are generally more bioavailable and convenient for precise dosing in clinical studies, whereas tea and dried forms may have lower absorption rates but retain additional plant compounds. The extract form is most commonly used in research, making it the preferred choice for replicating studied benefits.

### Who should avoid selfheal, and are there specific populations at higher risk for side effects?

Individuals taking immunosuppressive medications should consult a healthcare provider before using selfheal, as it may enhance immune function and potentially interfere with immunosuppression therapy. People with autoimmune thyroid disorders (such as Hashimoto's or Graves' disease) should use selfheal cautiously and under medical guidance, as its immune-modulating effects could theoretically affect disease progression. Elderly individuals with compromised kidney or liver function should also seek professional guidance, as adequate safety data in these populations is limited.

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