Geranium: herbal tea, medicine or oil?
In short: the word « geranium » hides three different health plants. Herb Robert, a true wild geranium, has been drunk as a herbal tea for centuries, but no human trial shows that it cures anything. Cape pelargonium (Pelargonium sidoides, or umckaloabo) is the only one recognised by the European Medicines Agency, as a « traditional use » for the symptoms of the common cold from age 6; trials exist, but they are of low quality. Rose geranium is used as an essential oil: it smells lovely, but it irritates, can make you allergic, and must not be swallowed.
Updated on 21 October 2026.
Three plants behind one name
The « geranium » sold in garden centres is almost always a Pelargonium, a southern African genus that botanists separated from the true Geranium in 1789. Everyday language never followed, and neither did the health shelves: depending on the label, « geranium » can mean a wild plant from our hedgerows, a South African root sold in pharmacies or an essential oil. The story of this confusion is told on fleurs.be, in our articles on hardy geraniums and on the pelargonium.
| Common name | Plant | Part used | Form | Status in Europe |
|---|---|---|---|---|
| Herb Robert | Geranium robertianum (true geranium) | Whole flowering plant | Herbal tea, gargle, external use | No European monograph found |
| Umckaloabo, Cape pelargonium | Pelargonium sidoides | Root | Liquid or dry extract (syrup, drops, tablets) | EMA monograph: traditional use, common cold |
| Rose geranium | Pelargonium graveolens and its hybrids | Distilled leaves and stems | Essential oil | Perfumery, cosmetics; irritant and sensitiser |
Herb Robert: the only true « geranium tea »
Herb Robert (Geranium robertianum). Photo by sannse, Tapeley Park, Instow, North Devon, 14 May 2004. CC BY-SA 3.0
It is a true geranium, very common in Belgium at the foot of hedges and walls and in woodland: small pink flowers, finely divided foliage that turns red in the sun, reddish stems and a strong smell when crushed. Unlike most of its garden cousins, it is an annual or biennial.
What tradition says
The list of traditional uses is long, and that in itself is a clue: a plant said to cure everything has rarely been tested for anything. A review published in 2025 lists, taken internally, diarrhoea, gastritis, ulcers, flu, sinusitis, diabetes, high blood pressure, cholesterol, rheumatism, liver disorders and even cancer; used externally, wounds, burns, cold sores, varicose veins and mouth inflammations (Haj Ali et al., 2025).
What studies show
The plant is rich in tannins, in particular geraniin, and in flavonoids. Tannins are astringent: they tighten tissues and reduce secretions, which probably explains their use against diarrhoea and as a gargle. But the vast majority of research has been done in test tubes (antibacterial and antioxidant activity, effects on cancer cells) or in mice (stomach ulcers, blood sugar). The same review cites only two human studies: ear drops that combined herb Robert, clove and lavender, as effective as an antibiotic against external otitis, which says nothing about herb Robert alone; and a cosmetic trial on wrinkles around the eyes, with no significant improvement. The authors themselves conclude that knowledge remains « relatively limited ».
Reference sheets agree: for none of the traditional uses is the evidence sufficient to rate effectiveness; oral safety is poorly known, no dose has been established and, for lack of data, it is wiser to avoid it during pregnancy and breastfeeding (RxList, n.d.).
Verdict: traditional use, plausible for a local astringent action, not demonstrated in humans.
Cape pelargonium (umckaloabo): the only one with medicine status
Leaves of Pelargonium sidoides. Photo taken at the Chanticleer Garden, where the plant was identified. Photo by Derek Ramsey (Ram-Man). CC BY-SA 3.0
The story of a patent medicine
The story begins at the turn of the 20th century. The Englishman Charles Henry Stevens, suffering from tuberculosis, went to southern Africa to recover; he claimed to have been cured by a Sotho healer, in Basutoland (today's Lesotho), with a root called « umckaloabo ». Back in England, he sold it as a remedy for consumption, the « Stevens' consumption cure ». In 1909, the British Medical Association (BMA) published criticism of the remedy; Stevens sued the BMA in 1912 and lost, partly because he refused to reveal what it contained. In the 1920s and 1930s, the Swiss doctor Adrien Sechehaye nevertheless published favourable results, and umckaloabo took hold in Europe (Brendler et al., 2024).
A century later, the root became the subject of a legal battle. A German laboratory, maker of an extract of the root, had filed patents on its use. In January 2010, the European Patent Office revoked one of them, after an opposition supported by the community of Alice, in South Africa, which claimed the traditional knowledge behind the remedy; in April, the laboratory gave up five patents (Public Eye, 2010). A textbook case of what is known as biopiracy.
What the European Medicines Agency says
The EMA's herbal medicines committee published the revision of its monograph on pelargonium root in 2023 (EMA, 2024). Its conclusions:
- Indication: relief of the symptoms of the common cold.
- Status: traditional use, that is, based on long-standing use rather than on trials judged sufficient.
- Acute bronchitis: not accepted, as clinical trials were judged insufficient.
- Age: from 6 years.
- Duration: see a doctor if symptoms last more than a week or get worse.
- Side effects: very rare digestive upsets, minor nose or gum bleeding, allergic reactions; liver problems have been reported, at an unknown frequency.
What the trials show
The 2013 Cochrane review included eight trials (Timmer et al., 2013). In acute bronchitis, in adults (746 patients) as in children (819 children), the liquid form relieved most symptoms; the tablets did not. One trial on sinusitis and one on the common cold pointed the same way. But the quality of evidence is low for bronchitis and very low for sinusitis and colds, and one point weighs heavily: all the trials came from the same investigator, linked to the manufacturer, and from the same region (Ukraine and Russia), with possible signs of publication bias. The authors themselves express doubts. Side effects were more frequent than with placebo, but none were serious.
And the liver?
Reports of liver injury have been studied closely. An analysis of 13 spontaneously reported cases found none in which a link with pelargonium was probable: six were excluded, six unlikely, and the last was explained by another disease (Teschke et al., 2012). The EMA nevertheless keeps its warning: if jaundice, dark urine or liver pain appear, stop and see a doctor.
Verdict: weakly demonstrated for relieving a cold or bronchitis; official traditional-use status; trials all from the same manufacturer.
Rose geranium: an essential oil, not a tea
A bee on a rose geranium (Pelargonium graveolens), Athens, 4 May 2023. Photo by George E. Koronaios, own work. CC BY-SA 4.0
Rose geranium is a scented pelargonium from South Africa; its cultivars and hybrids are grown on Réunion and elsewhere for an oil that replaces the far more expensive rose oil in perfumery (Lawrence, 2002). The oil is obtained by steam distillation of the leaves and stems.
What it contains
According to the analysis accepted by the European Food Safety Authority (EFSA, 2023), its main components are citronellol (roughly a quarter to a third of the oil), geraniol (around 12%), citronellyl formate, isomenthone and linalool. These are precisely the molecules that give it its rose scent… and that cause problems for the skin.
The risks
- Irritation and allergy: EFSA considers the oil irritating to skin and eyes and sensitising to the skin and, for people who handle it, to the airways: with repeated contact, you can become allergic.
- Labelling: citronellol, geraniol and linalool are on the European list of fragrance allergens that cosmetics must name on the packaging above a very low concentration (Regulation (EU) 2023/1545).
- Swallowing: an essential oil is not a concentrated tea. In Belgium, the pharmacovigilance centre has already reported children hospitalised after swallowing preparations based on essential oils (CBIP, 2008). Keep it out of children's reach, then, and never take it by mouth without medical advice.
What studies show
Human studies are rare and small. The most cited: an Iranian trial in 100 women expecting their first child, during the first stage of labour. Those who inhaled the scent of geranium oil had lower anxiety scores and lower diastolic blood pressure than the placebo group (Rashidi Fakari et al., 2015). It is a single trial, in a single hospital, on a subjective outcome: a hint, not proof.
Verdict: pleasant scent, a relaxing effect that is possible but barely studied; skin risks well documented.
The verdict table
| Claim | Plant | Human studies | Level of evidence |
|---|---|---|---|
| Relieve a cold | Umckaloabo | A few trials, all linked to the manufacturer | Low to very low; traditional use accepted by the EMA |
| Relieve acute bronchitis | Umckaloabo | 6 trials (adults and children) | Low; not accepted by the EMA |
| Calm diarrhoea, a sore throat | Herb Robert | No study of the plant alone | Tradition only |
| Diabetes, cholesterol, cancer | Herb Robert | None | Test tube and mice only |
| Reduce anxiety (inhalation) | Rose geranium | 1 small trial | Very low |
| Keep mosquitoes away | « Citronella » pelargonium | Field trial in 1996 | False: no protection (see fleurs.be) |
Who is it for? And who should avoid it?
- A cold in an adult or a child over 6: umckaloabo is a regulated self-care option, to be taken according to the leaflet. It is not an antibiotic and does not replace one when one is needed.
- Pregnant or breastfeeding women: the EMA advises against umckaloabo for lack of data; the same caution applies to herb Robert and the essential oil.
- Liver disease: ask your doctor before taking umckaloabo.
- Sensitive skin, eczema, known fragrance allergy: avoid rose geranium essential oil, or test it first on a small area, diluted.
- Young children: no essential oil within their reach; no umckaloabo under 6 without medical advice.
In practice
- Read the label: the Latin name tells you which plant it is. Geranium or Pelargonium do not have the same effects, and what is known about umckaloabo applies neither to other pelargoniums nor to rose geranium oil.
- Umckaloabo: a pharmacy product, with a leaflet and a dosage. If the cold lasts more than a week, gets worse, or comes with a high fever or breathlessness, see a doctor.
- Herb Robert: no dose has been established. If you pick it yourself, be sure of the identification and choose an untreated spot away from roads.
- Essential oil: in a diffuser or in a vegetable oil for the skin, never neat or swallowed; stored out of children's reach.
- Interactions: tell your doctor or pharmacist about any plant you take, especially alongside long-term treatment.
Going further
Why tannins « work » in a test tube. Geraniin and other ellagitannins bind to proteins, including those of bacteria and viruses: that is what produces impressive results in laboratory cultures. But these large molecules are poorly absorbed by the gut and transformed by the gut microbiota; what acts in a test tube does not necessarily reach the target organ in humans. That is the whole gap between « antibacterial activity » and « cures an infection ».
Why trials all from one manufacturer are a problem. It is not proof of fraud; it is a risk of bias. When all the studies come from the same team, funded by the company that sells the product, the independent replication needed to say an effect is solid is missing. The Cochrane review stresses this, and it is why the EMA sticks to traditional use for the common cold.
Umckaloabo and wild harvesting. The root is harvested in South Africa and Lesotho; the 2010 patent dispute raised the question of sharing benefits with the communities that held the original knowledge, in the sense of the Convention on Biological Diversity.
Test yourself
Sources
- Belgian Centre for Pharmacotherapeutic Information. (2008). Mauvaise utilisation de préparations à base d'huiles essentielles. Folia Pharmacotherapeutica, 35(4). https://www.cbip.be/folia_pdfs/FR/P35F04G.pdf
- Brendler, T., Stander, M. A., & van Wyk, B.-E. (2024). Stevens' Cure (Umckaloabo): The vindication of a patent medicine. Frontiers in Pharmacology, 14, 1294997. https://doi.org/10.3389/fphar.2023.1294997
- Commission Regulation (EU) 2023/1545 of 26 July 2023 amending Regulation (EC) No 1223/2009 as regards labelling of fragrance allergens in cosmetic products. (2023). Official Journal of the European Union. https://eur-lex.europa.eu/eli/reg/2023/1545/oj
- EFSA Panel on Additives and Products or Substances used in Animal Feed, Bampidis, V., et al. (2023). Safety and efficacy of a feed additive consisting of an essential oil from the herbaceous parts of Pelargonium graveolens L'Hér. (geranium rose oil) for all animal species (FEFANA asbl). EFSA Journal, 21(7), e08161. https://doi.org/10.2903/j.efsa.2023.8161
- European Medicines Agency. (2024). Pelargonii radix: Herbal medicinal product. EMA. https://www.ema.europa.eu/en/medicines/herbal/pelargonii-radix
- Haj Ali, D., Dărăban, A. M., Ungureanu, D., Căta, A., Ienașcu, I. M. C., Dinu, S., Dehelean, C. A., & Danciu, C. (2025). An up-to-date review regarding the biological activity of Geranium robertianum L. Plants, 14(6), 918. https://doi.org/10.3390/plants14060918
- Lawrence, E. (2002). Pelargonium graveolens. PlantZAfrica, SANBI. https://pza.sanbi.org/pelargonium-graveolens
- Public Eye. (2010, April 26). Major breakthrough in the fight against biopiracy: German pharmaceutical Schwabe announces withdrawal of 5 pelargonium patents. https://www.publiceye.ch/en/media-corner/press-releases/detail/major-breakthrough-in-the-fight-against-biopiracy-german-pharmaceutical-schwabe-announces-withdrawal-of-5-pelargonium-patents
- Rashidi Fakari, F., Tabatabaeichehr, M., Kamali, H., Rashidi Fakari, F., & Naseri, M. (2015). Effect of inhalation of aroma of geranium essence on anxiety and physiological parameters during first stage of labor in nulliparous women: A randomized clinical trial. Journal of Caring Sciences, 4(2), 135–141. https://doi.org/10.15171/jcs.2015.014
- RxList. (n.d.). Herb Robert. https://www.rxlist.com/supplements/herb_robert.htm
- Teschke, R., Frenzel, C., Wolff, A., Herzog, J., Glass, X., Schulze, J., et al. (2012). Initially purported hepatotoxicity by Pelargonium sidoides: The dilemma of pharmacovigilance and proposals for improvement. Annals of Hepatology, 11(4), 500–512.
- Timmer, A., Günther, J., Motschall, E., Rücker, G., Antes, G., & Kern, W. V. (2013). Pelargonium sidoides extract for treating acute respiratory tract infections. Cochrane Database of Systematic Reviews, (10), CD006323. https://doi.org/10.1002/14651858.CD006323.pub3