Lungwort Benefits: Traditional Uses, Research, and Safety
There's a plant that grows in the damp shade of old-growth forests — its spotted, lung-shaped leaves clinging to the forest floor — that has been used for respiratory support since the Middle Ages. Native to Europe and Western Asia and now naturalized across parts of North America, lungwort caught the attention of early herbalists who followed the Doctrine of Signatures and believed the plant's resemblance to lung tissue was nature's way of signaling its purpose. Modern herbalists don't rely on that logic, but the tradition it inspired has proven remarkably persistent: lungwort benefits for respiratory comfort have kept it in continuous use across herbal medicine for over 500 years.
Lungwort (Pulmonaria officinalis) doesn't have the name recognition of echinacea or the trendiness of ashwagandha. It's a quiet, understated herb — and that's partly why it's worth paying attention to. The plants that stick around for centuries without fanfare tend to be the ones that actually work for people in practice, even when the clinical research hasn't caught up yet.
That said, let's be upfront: lungwort is one of the more under-researched herbs in the Western materia medica. Much of what we know about lungwort benefits is drawn from traditional use, ethnobotanical records, and a growing body of preclinical research rather than controlled clinical trials. This article will be transparent about where the evidence is strong, where it's preliminary, and where we're relying on traditional knowledge.
What Is Lungwort?
Lungwort (Pulmonaria officinalis) is a perennial flowering plant in the Boraginaceae (borage) family. It is native to damp, shaded habitats in Europe, Western Asia, and parts of North Africa, where it grows naturally in old-growth forests, woodland margins, and coastal areas. It is also known by the common names Common Lungwort, Jerusalem Sage, Jerusalem Cowslip, Spotted Dog, and Soldiers and Sailors — the last two names referencing the way its flowers change from pink to blue as they mature.
Important distinction: Lungwort (Pulmonaria officinalis) should not be confused with lungmoss (Lobaria pulmonaria), a type of lichen that sometimes shares the common name "lungwort." These are completely different organisms, though both have traditional respiratory uses.
Lungwort is a low-growing plant, typically reaching 10-12 inches in height, with distinctive oval leaves that are covered in white or light-green spots. These spotted leaves are what originally drew herbalists' attention — their mottled pattern resembled diseased lung tissue, which under the Doctrine of Signatures (a pre-scientific framework for identifying medicinal plants) suggested the plant was intended for lung ailments. While this reasoning doesn't hold up to modern scrutiny, the empirical tradition it sparked has been remarkably consistent across centuries.
One of lungwort's most interesting ecological characteristics is its sensitivity to environmental pollution. The plant requires clean air and undisturbed soil to thrive, which means its presence in a forest is often used as a bioindicator of ecosystem health. If you find lungwort growing wild, you're likely standing in a relatively unpolluted environment — which is a nice quality for a medicinal plant.
Lungwort's medicinal history stretches back to at least the 1500s in European herbal medicine, with documented use for coughs, chest complaints, and respiratory congestion. It was a staple of European monastery gardens and appears in numerous historical pharmacopoeias.
Herbal Actions of Lungwort
In traditional herbal medicine, lungwort is associated with several key actions. These classifications come from centuries of empirical observation and traditional use — they are not clinical claims and are not all validated by large-scale clinical trials.
Demulcent: Lungwort is rich in mucilage, a gel-like polysaccharide that creates a soothing, protective coating on mucous membranes when consumed. This is one of lungwort's most recognized traditional properties and is the basis for its use in soothing irritated throat and respiratory tissues.
Expectorant: Lungwort is traditionally classified as an expectorant, meaning it may help support the loosening and expulsion of mucus from the respiratory tract. This action is attributed to the interaction between its saponin and mucilage content — helping to thin congestion while simultaneously soothing the tissues involved.
Emollient: Closely related to its demulcent action, lungwort's mucilage content gives it a softening, moistening quality that is traditionally valued for soothing dry, irritated tissues.
Mild astringent: Lungwort contains tannins that give it gentle astringent properties — traditionally used to help tone and tighten mucous membrane tissue. This mild tightening action is thought to complement its demulcent and expectorant effects.
Mild diuretic: In some traditional European systems, lungwort has been used as a gentle diuretic — promoting fluid movement and urinary output. This is a secondary traditional action, not its primary use.
Antioxidant: Modern analysis has confirmed that lungwort contains a range of antioxidant compounds, including flavonoids and phenolic acids. While this isn't a traditional herbal "action" in the classical sense, it reflects the plant's phytochemical profile.
Key Compounds in Lungwort
Lungwort's traditional uses are supported by a diverse — though still incompletely characterized — phytochemical profile. Here are the key compound groups that have been identified.
Mucilage polysaccharides: These are the compounds responsible for lungwort's demulcent and emollient properties. When the plant material contacts water, mucilage forms a thick, gel-like substance that coats and soothes mucous membranes. This is the same class of compounds that makes marshmallow root and slippery elm effective as soothing agents.
Tannins (particularly catechol tannins): These give lungwort its mild astringent quality. Tannins work by binding to proteins on the surface of tissues, creating a tightening effect that can help reduce minor irritation and support tissue integrity.
Flavonoids (including quercetin and kaempferol): These are well-studied antioxidant compounds found across the plant kingdom. In preclinical research, quercetin and kaempferol have shown anti-inflammatory and antioxidant activity, though human clinical studies on lungwort-derived flavonoids specifically are absent.
Allantoin: This compound is found in several medicinal plants (most notably comfrey) and has been studied for its potential role in supporting tissue repair and soothing irritated skin. In lungwort, allantoin may contribute to the herb's traditional reputation for soothing respiratory tissues.
Silicic acid (silica): Present in small amounts, silicic acid is thought to support connective tissue integrity. Some traditional herbalists associate lungwort's silica content with its ability to support respiratory tissue health over time.
Saponins: These surfactant-like compounds may contribute to lungwort's expectorant action by helping to break down and thin mucus in the airways.
Phenolic acids (including rosmarinic acid, caffeic acid, and salvianolic acids): Recent phytochemical analyses (2021–2024) have identified rosmarinic acid as one of the dominant phenolic compounds in Pulmonaria officinalis. Rosmarinic acid has been studied extensively in other plants (rosemary, lemon balm) for its antioxidant and anti-inflammatory properties. In lungwort, the phenolic acid profile may contribute significantly to the herb's overall antioxidant and tissue-protective activity observed in laboratory settings.
As with many traditional herbs, the research characterizing lungwort's phytochemistry is developing — and accelerating. Recent studies (2021–2025) have expanded our understanding of Pulmonaria species' bioactive profiles, confirming significant antioxidant capacity and identifying compounds of interest for further investigation. However, comprehensive pharmacokinetic studies (examining how these compounds behave in the human body) are still largely absent.
Lungwort Benefits: Traditional and Evidence-Based
Based on traditional use, ethnobotanical records, and limited preliminary research, here are the most commonly discussed benefits of lungwort. These reflect historical and traditional applications — not clinically proven outcomes.
Respiratory Comfort and Mucus Support
This is lungwort's primary traditional application and the reason it has been used continuously for centuries. The combination of its mucilage (which soothes irritated respiratory tissue) and its expectorant compounds (which may help thin and mobilize mucus) makes it a classic choice for respiratory comfort in the European herbal tradition. Herbalists have traditionally used it for dry or productive coughs, chest congestion, and general respiratory discomfort.
Evidence level: Extensive traditional use in European herbalism spanning centuries. Preclinical research supports the plausibility of these mechanisms — recent in vitro studies (2021) on Pulmonaria officinalis extracts found measurable protection against peroxynitrite-induced damage in plasma and demonstrated COX-2 inhibitory activity, suggesting anti-inflammatory potential relevant to respiratory tissue. No controlled human clinical trials specifically on lungwort for respiratory outcomes.
Soothing Irritated Throat and Airway Tissue
Lungwort's high mucilage content is the basis for its traditional use in soothing irritated throat and airway tissue. When consumed as a tea or tincture, the mucilage forms a protective layer over irritated membranes, which may temporarily reduce discomfort. This mechanism is well-understood from other mucilage-rich herbs like marshmallow root, and is considered pharmacologically plausible.
Evidence level: Well-established traditional use; the demulcent mechanism is pharmacologically understood. Clinical data on lungwort specifically is limited.
Antioxidant and Anti-Inflammatory Support
Laboratory analyses have confirmed that lungwort contains a robust antioxidant profile, including flavonoids such as quercetin and kaempferol, as well as phenolic acids — with rosmarinic acid identified as a dominant compound in recent analyses. Studies on Pulmonaria officinalis extracts have found measurable free radical scavenging activity and protection against oxidative DNA damage in vitro. A 2021 study also demonstrated COX-2 inhibitory activity (an enzyme involved in inflammatory pathways), which is notable given lungwort's traditional use for soothing inflamed respiratory tissue. However, in vitro activity doesn't automatically translate to meaningful effects in the human body.
Evidence level: Preclinical studies (2017–2025) confirm antioxidant compounds, free radical scavenging, COX-2 inhibition, and DNA-protective effects in laboratory settings. Human clinical data on lungwort's antioxidant or anti-inflammatory effects is lacking.
Digestive Comfort
A lesser-known traditional application — lungwort tea has historically been used in European folk medicine for mild digestive complaints, including occasional indigestion and minor gastrointestinal discomfort. The mucilage content likely plays a soothing role here as well, similar to how marshmallow root is used for both respiratory and digestive mucous membrane support.
Evidence level: Traditional use in European folk medicine. No clinical research on this specific application.
Topical Skin Support
Lungwort's allantoin content has made it a traditional choice for minor topical applications. Allantoin is a compound found in several plants (most notably comfrey) and is widely used in skincare for its potential soothing and moisturizing properties. Traditionally, lungwort poultices were applied to minor skin irritations.
Evidence level: Traditional topical use. Allantoin has been studied in other contexts, but no clinical research exists on topical lungwort specifically.
Emerging Preclinical Research
Beyond its established traditional uses, recent laboratory studies have begun exploring lungwort's broader pharmacological potential. Preliminary findings include acetylcholinesterase (AChE) inhibitory activity — an enzyme target relevant to cognitive research — and α-glucosidase inhibition, which is of interest in metabolic health research. A 2025 pharmacometabolomic study also explored potential neuroprotective mechanisms in Pulmonaria species through TLR4 pathway modulation.
These findings are very early-stage — in vitro and animal models only — and should not be interpreted as evidence that lungwort has cognitive, metabolic, or neuroprotective benefits in humans. They are mentioned here for completeness and because they represent an interesting direction for future research on this historically underexplored herb.
Evidence level: Preliminary in vitro and animal studies only. No human data. Interesting but far from actionable.
How to Use Lungwort
Lungwort is less widely available as a standalone herb than some of its better-known counterparts (like mullein or marshmallow root), but it can be found through specialty herbal suppliers and in respiratory-focused herbal blends.
Lungwort Tea
Steep 1-2 teaspoons of dried lungwort leaf in freshly boiled water for 10-15 minutes. The resulting tea has a mild, slightly astringent flavor with a smooth, mucilaginous texture. Some people add honey or lemon for taste.
Traditional dosing: 1-3 cups daily during periods of respiratory discomfort.
Tincture
Lungwort tinctures (alcohol or glycerin extracts) provide a more concentrated and portable preparation. Follow the dosing guidance on the specific product label, as concentrations vary between manufacturers and extraction methods.
Herbal Blends
Lungwort is most commonly encountered today as part of respiratory herbal formulations, where it is combined with complementary herbs. Traditional pairings include lungwort with mullein, plantain leaf, elecampane, thyme, or osha root — herbs that share an affinity for respiratory support through complementary mechanisms.
Our Lung Clear & Support Tonic features lungwort alongside mullein, osha root, plantain leaf, and spearmint leaf — a combination of herbs traditionally used to support respiratory comfort, promote mucus clearance, and soothe irritated airways. The formula uses a therapeutic extraction process to concentrate the active compounds into a bioavailable liquid extract.
Safety, Side Effects, and Precautions
Lungwort has a long history of traditional use and is generally considered a gentle herb. However, as with all herbal supplements, there are important considerations.
Generally well-tolerated. Lungwort tea and tinctures are considered safe for most adults when used at standard doses for short-to-medium-term periods. Serious side effects are not commonly reported in the traditional literature.
Pyrrolizidine alkaloid (PA) concern. This is the most important safety consideration for lungwort. Some plants in the Boraginaceae family (which includes lungwort) can contain pyrrolizidine alkaloids — compounds that, in sufficient quantities, may be harmful to the liver. The levels in Pulmonaria officinalis aerial parts (leaves) are generally considered to be very low to trace — often undetectable or negligible in recent analytical studies — compared to high-PA plants like comfrey root. PA concentrations tend to be higher in roots than in leaves across the Boraginaceae family.
It's also worth noting that extraction method matters. Experienced herbalists and formulators can use specific extraction techniques — including selective solvent systems, filtration methods, and careful attention to which plant parts are extracted — that may further reduce PA content in finished tinctures and liquid extracts compared to crude whole-plant preparations. This is one reason why working with knowledgeable formulators and reputable manufacturers is important when it comes to Boraginaceae-family herbs. A well-made tincture from an expert formulator using tested leaf material is a very different product from a homemade preparation using uncharacterized plant material.
Pregnancy and breastfeeding. There is insufficient safety data on lungwort use during pregnancy or breastfeeding. Given the PA consideration and the general lack of safety studies in these populations, it is advisable to avoid lungwort during pregnancy and nursing unless specifically directed by a qualified healthcare provider.
Allergies. Individuals with known allergies to plants in the Boraginaceae (borage) family should exercise caution. Allergic reactions to lungwort are rare but possible.
Drug interactions. No significant drug interactions have been widely reported, but lungwort has mild diuretic properties in some traditional systems. Individuals taking diuretic medications should be aware of potential additive effects. As always, consult your healthcare provider before combining any herbal supplement with prescription medications.
Duration of use. Because of the pyrrolizidine alkaloid consideration, most herbalists recommend using lungwort for defined periods (e.g., during acute respiratory discomfort) rather than as a continuous daily supplement indefinitely. Consult a qualified herbalist or healthcare provider for guidance on appropriate duration.
Quality and sourcing. Choose lungwort products from reputable suppliers who conduct third-party testing for contaminants, including heavy metals, pesticides, microbial contamination, and — ideally — pyrrolizidine alkaloid levels.
The Bigger Picture: Supporting Respiratory Health Holistically
Lungwort is a valuable herb for respiratory support, but lasting respiratory wellness comes from a holistic approach that addresses the whole picture.
The air you breathe matters more than almost anything else when it comes to lung health. If you spend most of your time indoors — as most of us do — the quality of your indoor air has an outsized impact. Consider investing in a good HEPA air filter for the rooms where you spend the most time, particularly your bedroom. Reduce your use of synthetic fragrances, harsh chemical cleaners, and aerosol products. Open windows when weather and outdoor air quality permit.
Hydration plays an underappreciated role in respiratory comfort. Well-hydrated mucous membranes are better able to trap and clear irritants, and adequate fluid intake helps keep mucus at a healthy consistency rather than becoming thick and stagnant. Herbal teas — including lungwort — serve a dual purpose here, providing both hydration and herbal support.
Regular physical activity supports your cardiovascular and respiratory systems. Even moderate daily movement — walking, swimming, cycling — helps improve lung capacity and the efficiency of oxygen exchange. Deep breathing exercises, whether practiced through yoga, tai chi, or simple daily breathwork, can further support lung function.
And of course, the fundamentals matter: adequate sleep for immune recovery, balanced nutrition for overall resilience, and stress management to keep your immune system functioning well. Herbs like lungwort are most effective when they're layered on top of these foundational practices rather than expected to compensate for their absence.
References
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