Lungwort

Lungwort (Pulmonaria officinalis) is a low-growing woodland herb in the borage family, easy to spot for its dark green leaves splashed with pale white patches — markings that, to medieval eyes, looked like the mottled surface of a lung. That resemblance is the whole reason for its name and its old reputation as a chest and cough herb. This page tells that story honestly: how the leaf's lung-like look, filtered through a pre-scientific idea called the doctrine of signatures, turned lungwort into a traditional remedy for coughs, bronchitis, and sore throats. We also clear up two common mix-ups (lungwort the leaf plant is not the same as "lungwort lichen," and it is not mullein), walk through what the plant actually contains, and look at what modern lab studies do and do not show. Along the way we flag a real safety point: like other borage-family plants, lungwort can carry small amounts of liver-stressing compounds called pyrrolizidine alkaloids, so it is best used gently and short-term. Think of this as a gentle, folkloric herb with a charming backstory rather than a proven medicine.

Table of Contents

  1. What Lungwort Is
  2. Not to Be Confused With: The Lichen and Mullein
  3. The Doctrine of Signatures: How Lungwort Got Its Name
  4. Traditional Uses
  5. The Active Compounds
  6. What the Evidence Shows
  7. Forms and How It Is Used
  8. Safety and Cautions
  9. The Honest Bottom Line
  10. Research Papers
  11. Connections
  12. Featured Videos

What Lungwort Is

Lungwort is a small perennial plant native to the woodlands and shady hedgerows of Europe. Botanically it is Pulmonaria officinalis, a member of the Boraginaceae — the borage and forget-me-not family, which also includes comfrey and borage. It rarely grows more than a foot tall, spreading in low clumps on the forest floor and flowering in early spring.

Two features make it instantly recognizable. First, the leaves: they are oval, rough to the touch, and dusted with irregular pale-white or silvery spots, as if someone flicked drops of milk across them. Second, the flowers, which perform a small color trick common in the borage family — the buds open pink or reddish and then shift to blue or violet as they age, so a single plant often shows both colors at once. This gave rise to folk names like "soldiers-and-sailors" and "Joseph-and-Mary." The white-spotted leaves inspired other tender names, including "Our Lady's milk drops," from a legend that the spots were drops of the Virgin Mary's milk.

The word to hold onto is spotted. Throughout this page, "lungwort" means this specific spotted-leaf borage-family plant, Pulmonaria officinalis. That matters because at least two other things share the name or the reputation, and it is easy to get them tangled — which is exactly what the next section untangles.

Not to Be Confused With: The Lichen and Mullein

Because "lungwort" is really a nickname earned by looking lung-like, more than one organism has been called by it over the centuries. Before going further, it helps to sort them out.

Lungwort lichen (Lobaria pulmonaria)

There is a completely separate organism called lungwort lichen, or tree lungwort, whose scientific name is Lobaria pulmonaria. It is not a plant at all — it is a lichen, a partnership between a fungus and photosynthetic algae, and it grows in ridged, lobed, leathery sheets on the bark of old trees in clean-air forests. Its deeply grooved surface also resembles lung tissue, so it too was used in traditional European medicine for coughs and lung complaints. The two "lungworts" are unrelated: one is a flowering woodland herb, the other is a tree-dwelling lichen. This page is about the herb, not the lichen, but it is worth knowing the lichen exists so old herbals and product labels do not confuse you.

Mullein (Verbascum thapsus)

Mullein is a different herb entirely — a tall, fuzzy-leaved plant in the figwort family — but people often lump it together with lungwort because it is another classic "lung herb," a soothing remedy used for coughs and bronchitis. They are not the same plant and are not even close relatives. If a recipe, tea blend, or old text mentions a lung herb, it is worth checking whether it means lungwort, mullein, or the lichen, since all three earned respiratory reputations by different routes.

The Doctrine of Signatures: How Lungwort Got Its Name

Lungwort's name and its traditional use come from one of the most interesting ideas in the history of herbalism: the doctrine of signatures. This was the belief — popular in medieval and Renaissance Europe, and associated with thinkers such as Paracelsus — that a plant's outward appearance was a kind of divine label, a "signature" hinting at what part of the body it was meant to heal. A walnut, folded like a brain, was thought good for the head. A plant with yellow sap was thought good for jaundice. And a leaf mottled and spotted like a diseased lung, veined and pouchy like the air sacs inside the chest, must surely be the remedy for lungs.

That leaf was lungwort. Its Latin name, Pulmonaria, comes straight from pulmo, the Latin word for lung. Herbalists looked at the spotted foliage, read it as a signature for respiratory illness, and prescribed the plant for coughs, congestion, and chest complaints. The English name "lungwort" simply means "lung plant" (wort is an old word for a useful herb).

It is important to be honest here. The doctrine of signatures was a historical belief, not a scientific principle. A plant's shape tells us nothing real about its chemistry or its effects on the body; plenty of "signature" cures did nothing, and the reasoning was backwards. Yet the story does not end there. Once lungwort entered the herbal tradition, it was used, observed, and passed down for centuries as a genuine folk remedy for the respiratory tract. Whether it does much is a separate question, taken up below — but the plant's soothing, mucilage-rich nature meant the tradition was not entirely arbitrary, even if the original reason for reaching for it was a poetic misunderstanding rather than evidence.

Traditional Uses

In European folk medicine, lungwort was valued mainly as a gentle demulcent and mild expectorant for the airways. A demulcent is a herb rich in slippery, gel-like substances (mucilage) that coat and soothe irritated tissues — the same reason a spoonful of honey or a marshmallow-root tea eases a raw throat. Traditional herbalists reached for lungwort tea and syrup for:

Lungwort also carries a second, less-famous reputation as an astringent — a herb whose tannins gently tighten and tone tissue. This is where the demulcent story becomes a bit contradictory, and traditional texts made a virtue of both: the soothing mucilage was said to calm and coat, while the astringent tannins were said to firm up weepy, over-secreting membranes. On that logic, lungwort was applied not just to the respiratory tract but also to the urinary tract for mild irritation, and taken for looseness of the bowels. Externally, the crushed leaf or a strong wash was used on minor wounds, cuts, and hemorrhoids, a use that fits with the plant's allantoin content (see below), since allantoin is a genuine tissue-soothing compound.

The young leaves were also eaten as a wild spring green in parts of Europe, cooked into soups or added to salads — though, as the safety section explains, that is not something to do freely or often.

The Active Compounds

Lungwort's chemistry is a reasonable fit for its soothing, astringent traditional roles. Studies of the leaves and aerial parts have reported the following main groups of compounds:

What the Evidence Shows

Here is the honest picture. Lungwort's reputation rests overwhelmingly on tradition, supported by a modest and fairly recent set of laboratory studies. What is essentially missing is the kind of evidence that matters most for a cough remedy: rigorous, randomized human clinical trials. As far as the published literature goes, there are no good controlled trials showing that lungwort treats bronchitis, cough, or any respiratory illness in people. So when you read that lungwort is "good for the lungs," that claim is traditional, not clinically proven.

What the lab studies do show is more limited but still real:

In short: lungwort is chemically interesting and mildly active in the lab, its traditional demulcent role is chemically plausible, but its respiratory use remains a folk use awaiting real human trials. That is not a reason to dismiss it — many gentle traditional herbs are used comfortably without trial data — but it is a reason not to rely on it for a serious chest infection in place of medical care.

Forms and How It Is Used

Lungwort is a gentle herb, and the traditional preparations are simple. The most common are:

Because there are no clinical trials, there is no established "correct" dose — traditional amounts are modest, and the sensible approach is to use the smallest amount that helps, for the shortest time, rather than large quantities or daily use over weeks. The safety section explains why that restraint matters.

Safety and Cautions

Lungwort is generally regarded as a mild, low-risk herb, but it carries one caution worth taking seriously. Like comfrey, borage, and its other relatives in the borage family (Boraginaceae), lungwort can contain pyrrolizidine alkaloids (PAs). Certain PAs are known to be hepatotoxic — that is, toxic to the liver — and with heavy or prolonged exposure they can damage the small veins of the liver and are considered potentially genotoxic and carcinogenic. This is not a fringe worry; it is why several borage-family plants are restricted or used only externally in some countries.

The reassuring part is one of degree. Lungwort's PA content is low, much lower than in high-PA plants, and the alkaloids are concentrated mostly in the roots, with only trace amounts measured in the leaves that are actually used for tea. That means occasional, short-term use of leaf tea is a very different thing from chronic daily dosing or eating the plant regularly. Still, because there is no safe way to be sure how much PA any given batch contains, the prudent, widely-shared guidance is:

Finally, the common-sense point: lungwort is a soothing folk remedy, not a treatment for serious illness. Shortness of breath, a high fever, coughing up blood, or a cough that drags on or worsens are reasons to see a clinician, not to reach for a woodland herb. Used gently and briefly by a healthy adult, lungwort is low-risk; used heavily, chronically, or by someone in one of the groups above, the PA caution is real.

The Honest Bottom Line

Lungwort is a gentle, old-fashioned respiratory herb with one of the most charming origin stories in the whole herbal tradition: a spotted, lung-shaped leaf that medieval healers, following the doctrine of signatures, read as nature's own prescription for the chest. That reasoning was pre-scientific and, on its own terms, wrong — but it launched a genuine centuries-long tradition of using lungwort as a soothing demulcent for coughs, bronchitis, and sore throats, and the plant's mucilage, tannins, and rosmarinic-acid-rich phenolics give that tradition a plausible, if unproven, chemical footing.

Modern research is limited and mostly confined to the lab: lungwort is a decent antioxidant with some anti-inflammatory activity in test tubes, but there are no solid human trials behind its respiratory reputation. And because it belongs to the borage family, it deserves a sensible short-term, in-moderation approach, with a firm avoid in pregnancy, breastfeeding, and liver disease on account of its trace pyrrolizidine alkaloids. If you want a well-characterized soothing cough herb, better-studied demulcents like marshmallow root or mullein are reasonable choices. Lungwort's real appeal is as a mild, historically rich folk remedy — lovely to know about, gentle to use briefly, and honest about the fact that its evidence is thin.

Research Papers

  1. Krzyżanowska-Kowalczyk J, Pecio Ł, Mołdoch J, Ludwiczuk A, Kowalczyk M. Novel phenolic constituents of Pulmonaria officinalis L. LC-MS/MS comparison of spring and autumn metabolite profiles. Molecules. 2018;23(9):2277. doi:10.3390/molecules23092277 — Detailed chemical map showing lungwort leaves are dominated by rosmarinic acid and related caffeic-acid phenolics.
  2. Krzyżanowska-Kowalczyk J, Kowalczyk M, Ponczek MB, Pecio Ł, Nowak P, Kołodziejczyk-Czepas J. Pulmonaria obscura and Pulmonaria officinalis extracts as mitigators of peroxynitrite-induced oxidative stress and cyclooxygenase-2 inhibitors — in vitro and in silico studies. Molecules. 2021;26(3):631. doi:10.3390/molecules26030631 — Lungwort extracts reduced oxidative damage to blood plasma and inhibited the inflammation enzyme COX-2 in the lab.
  3. Neagu E, Radu GL, Albu C, Paun G. Antioxidant activity, acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum extracts. Saudi J Biol Sci. 2018;25(3):578–585. doi:10.1016/j.sjbs.2016.02.016 — Measured antioxidant capacity and enzyme-inhibiting activity of lungwort extracts in vitro.
  4. Ignjatijević A, Anđić T, Lješević M, Nikolić B, Ganić T, Spasović S, Vuletić S. Assessment of antioxidant activity and dose-dependent effect on genotoxicity/antigenotoxicity of Pulmonaria officinalis ethanolic extract. Pharmaceutics. 2025;17(9):1134. doi:10.3390/pharmaceutics17091134 — Recent study of lungwort's antioxidant activity and its dose-dependent effects on DNA-level toxicity.
  5. Amoah SKB, Sandjo LP, Kratz JM, Biavatti MW. Rosmarinic acid — pharmaceutical and clinical aspects. Planta Med. 2016;82(5):388–406. doi:10.1055/s-0035-1568274 — Review of rosmarinic acid, the main phenolic compound in lungwort, and its anti-inflammatory and antioxidant pharmacology.
  6. Haberer W, Witte L, Hartmann T, Dobler S. Pyrrolizidine alkaloids in Pulmonaria obscura. Planta Med. 2002;68(5):480–482. doi:10.1055/s-2002-32088 — Found lycopsamine-type PAs concentrated in roots and rhizomes, with only trace amounts in the leaves and flowers of a close lungwort relative.
  7. Lüthy J, Brauchli J, Zweifel U, Schmid P, Schlatter C. [Pyrrolizidine alkaloids in medicinal plants of Boraginaceae: Borago officinalis L. and Pulmonaria officinalis L.]. Pharm Acta Helv. 1984;59(9–10):242–246. PubMed: 6483923 — Early direct measurement of pyrrolizidine alkaloids in lungwort and borage.
  8. El-Shazly A, Wink M. Diversity of pyrrolizidine alkaloids in the Boraginaceae: structures, distribution, and biological properties. Diversity. 2014;6(2):188–282. doi:10.3390/d6020188 — Comprehensive review of the PA class across the borage family, to which lungwort belongs.
  9. Moreira R, Pereira DM, Valentão P, Andrade PB. Pyrrolizidine alkaloids: chemistry, pharmacology, toxicology and food safety. Int J Mol Sci. 2018;19(6):1668. doi:10.3390/ijms19061668 — Reviews why PAs matter for safety, including their hepatotoxicity and presence in herbal products.
  10. Yan X, Kang H, Feng J, Yang Y, Tang K, Zhu R, Yang L, Wang Z, Cao Z. Identification of toxic pyrrolizidine alkaloids and their common hepatotoxicity mechanism. Int J Mol Sci. 2016;17(3):318. doi:10.3390/ijms17030318 — Explains how certain PAs are converted to reactive metabolites that damage the liver.
  11. Zan K, Wang Z, Hu X, Li Y, Wang Y, Jin H, Zuo T, Ma S. Pyrrolizidine alkaloids and health risk of three Boraginaceae used in traditional medicine. Front Pharmacol. 2023;14:1075010. doi:10.3389/fphar.2023.1075010 — Assesses PA exposure and risk from borage-family medicinal plants.
  12. Jayawickreme K, Świstak D, Ozimek E, Reszczyńska E, Rysiak A, Makuch-Kocka A, Hanaka A. Pyrrolizidine alkaloids — pros and cons for pharmaceutical and medical applications. Int J Mol Sci. 2023;24(23):16972. doi:10.3390/ijms242316972 — Balanced overview of the risks and possible uses of the PA class found in borage-family herbs.

Back to Table of Contents

Connections

Back to Table of Contents