Chamomile

Matricaria chamomilla L. belongs to Asteraceae (Compositae), the daisy or sunflower family, in the order Asterales. Kew’s Plants of the World Online accepts it as the correct name and lists 54 synonyms, two of which matter to anyone reading labels or research. Linnaeus published both Matricaria chamomilla and Matricaria recutita on the same page of Species Plantarum in 1753, and the second name became standard in pharmacy: EMA’s monographs and the European Pharmacopoeia still use Matricaria recutita, and NCCIH lists both. Chamomilla recutita, coined by Rauschert in 1974, is a third synonym common in older literature. Britannica notes that many species of the related genus Anthemis are also called chamomile, including mayweed or stinking chamomile (Anthemis cotula), a strong-smelling weed. The English word goes back through Medieval Latin camomilla to the Greek chamaimēlon, built from chamai and mēlon, apple (Merriam-Webster); Aaqil and colleagues (AYUSHDHARA 2021) translate it as ‘ground apple’, probably for the flower’s apple-like fragrance.

German chamomile is an annual herb, usually 10 to 80 cm tall (Aaqil and colleagues). Its leaves are finely cut into narrow segments, twice pinnately divided in the Flora of Iraq’s description, which gives the plant its feathery look. Each long-stalked flower head has a ring of white ray florets, 6 to 10 mm long and often bent backward (reflexed), around a disc of tiny golden-yellow tubular florets (Flora of Iraq, via Kew); Srivastava and colleagues count about fifteen ray florets around the ‘hollow, bright gold cones’. The best identification test is to slice a flower head in half. In German chamomile the receptacle, the base on which the florets sit, is sharply conical, hollow, and free of the small chaffy scales (paleae) found in many relatives (EMA). In Roman chamomile, by contrast, the conical receptacle is covered with such scales. The tiny fruits have a pappus reduced to a small crown. In Iraq, where the Flora records it in waste places near cultivation, it flowers from April to June.

Kew gives the native range as Macaronesia (the Atlantic island groups off Europe and North Africa), North Africa, and temperate Eurasia to Indo-China, a sweep that takes in Germany, Hungary, Egypt, Pakistan, the western Himalaya, China, Korea, and Vietnam. It has been introduced to Canada and many US states, parts of Latin America, Britain, Ireland, Australia, and New Zealand, and grows mainly in the temperate biome. Aaqil and colleagues note cultivation in France, Germany, Hungary, Russia, the former Yugoslavia, and Brazil, and say that in India the plant arrived with the Mughals and is now grown in Punjab, Uttar Pradesh, Maharashtra, and Jammu and Kashmir. Egypt is a major exporter. A 2024 market study for CBI, which publishes trade guidance for exporters in developing countries, describes Egypt as a significant supplier of medicinal and aromatic plants, including chamomile, to Europe, largely from small-scale farmers, and ranks it the fourth-largest non-EU supplier of such plants in 2023, after India, the United States, and China. The same study calls China a major player in the global chamomile market.

The medicinal part is the dried flower head, Matricariae flos. The European Pharmacopoeia requires it to yield at least 4 ml of blue essential oil per kilogram and to contain at least 0.25% apigenin-7-glucoside (EMA). The flowers hold 0.3–1.9% essential oil, rich in (−)-α-bisabolol (up to half of the oil), bisabolol oxides, trans-β-farnesene, and spiroethers, along with up to 6% flavonoids, chiefly apigenin-7-glucoside, apigenin, and luteolin, small amounts of the coumarins herniarin and umbelliferone (0.01–0.08%), and mucilage. The fresh flower is not blue. Its sesquiterpene lactone matricin is converted to deep-blue chamazulene during steam distillation, which is why chamomile oil is blue (EMA); Srivastava and colleagues note that the oil turns dark yellow in storage. Cultivars and growing regions differ substantially in composition, and the Pharmacopoeia recognizes two types of oil, one rich in bisabolol oxides and one rich in α-bisabolol. Look-alikes are a quality problem: Srivastava and colleagues suggest that some allergic reactions blamed on chamomile may come from contamination with dog chamomile, a highly allergenic, bad-tasting plant of similar appearance.

Chamomile is one of the oldest documented medicinal plants. NCCIH notes that it was described in ancient medical writings and was an important medicinal herb in ancient China, Egypt, Greece, and Rome. Aaqil and colleagues add that Hippocrates described it as a medicinal plant and that Galen and Asclepiades prescribed chamomile tea as a calming drink, and EMA’s assessment report notes that Dioscorides mentioned its medical use. Pinning down exactly which plant the ancients meant is harder than it sounds, because several daisy-like species have shared the name. EMA’s assessment of Roman chamomile observes that the name Chamaemelum was first used by Dioscorides, but that it has proved impossible to trace that plant reliably in classical writings because so many similar species were described. The English name, borrowed through Medieval Latin, is first recorded in the thirteenth century (Merriam-Webster).

The great printed herbals of the sixteenth and seventeenth centuries made chamomile a staple of European pharmacy. EMA’s assessment report, drawing on a historical review by Benedum and colleagues (2006), cites Hieronymus Bock’s Kreutterbuch (1539), Leonhart Fuchs’s New Kreüterbuch (1543), Pietro Andrea Mattioli’s compendium based on his Dioscorides commentaries (1571), and Tabernaemontanus’s herbal (1613), and finds the literature consistent across the centuries: chamomile was applied to the skin for wound healing, used in the mouth for aphthous ulcers, and taken internally for digestive complaints and cramping. Aaqil and colleagues note that Mattioli listed chamomile oil as a remedy for spasms. Chamomile also has a long career in Unani medicine, the Greco-Arabic medical tradition, where it is called babuna and its flowers gul-e-babuna. Aaqil’s review lists babuna as the Urdu, Persian, and Marathi name and notes that classical Unani texts sometimes applied it to Roman chamomile and to an unrelated plant, until a later taxonomic study identified true babuna as Matricaria chamomilla.

In the twentieth century chamomile became one of the best-documented herbal medicines in Europe. Germany’s Commission E published its monograph on 5 December 1984, covering infusions of about 3 g of flowers in 150 ml of hot water, covered for 5 to 10 minutes and drunk three to four times a day between meals for gastrointestinal spasms and inflammation, gargles for the inflamed mouth and throat, inhalation for respiratory irritation, and washes, compresses, baths, and ointments for inflamed skin and mucosa, including the anal and genital area (EMA). The World Health Organization included it as Flos Chamomillae in the first volume of its monographs on selected medicinal plants in 1999, and ESCOP followed in 2003. EMA notes that the flower also appears in the European, British, and US pharmacopoeias. EMA’s Committee on Herbal Medicinal Products adopted a European Union monograph on the flower on 7 July 2015, with a companion monograph on the essential oil. Roman chamomile was never approved by Commission E, although EMA accepts it as a traditional remedy for mild cramping digestive complaints.

Outside continental Europe, chamomile’s popular identity drifted toward relaxation. NCCIH lists the common cold, indigestion, anxiety, insomnia, infant colic, and cough and bronchitis among the conditions it is promoted for today, along with skin use and mouthwashes, and MSKCC describes it as widely used in teas for its relaxing and calming effects. The CBI market study cites a 2021 UK survey in which eight in ten people said they turn to tea when stressed, with chamomile and lavender teas the most popular. Rigorous clinical research came relatively late. Amsterdam and colleagues published the first controlled trial of chamomile extract for generalized anxiety disorder in 2009, and the same team later ran a larger relapse-prevention study. In the United States, LactMed notes, chamomile is generally recognized as safe (GRAS) by the Food and Drug Administration as a spice, seasoning, or flavoring, which is why it is sold freely as tea, while capsules and extracts are sold as dietary supplements, which NCCIH notes are not approved by the FDA before they reach the public.

No single compound explains chamomile, and EMA notes that there are no data on how its constituents are absorbed, distributed, metabolized, or eliminated in people. Most mechanistic evidence comes from laboratory and animal work. In isolated guinea-pig intestine, α-bisabolol was 91% as effective as the smooth-muscle relaxant papaverine against chemically induced spasms, bisabolol oxides were about half as effective, and the flavonoid apigenin was 3.3 times more potent than papaverine (Achterrath-Tuckermann and colleagues 1980, cited by EMA). In mice, a chamomile extract slowed movement through the upper gut, and apigenin slowed intestinal transit in animals given castor oil to induce diarrhea. Chamazulene halved the production of leukotriene B4, an inflammatory signal, in rat white blood cells, and MSKCC cites work showing that chamomile inhibits COX-2, an enzyme that drives inflammation. EMA’s assessors judged the clinical relevance of the antispasmodic findings to be low, while accepting that they make the traditional digestive uses plausible.

The calming reputation centers on apigenin. MSKCC notes that apigenin interacts with GABA-A benzodiazepine receptors in laboratory studies, the same receptor family targeted by drugs such as diazepam. In mice, Viola and colleagues (1995) found an anxiety-reducing effect at 3 mg/kg, a dose similar to those used for benzodiazepines, and mild sedation only at 30 to 100 mg/kg, without diazepam’s muscle-relaxing effect. Avallone and colleagues (2000) could not reproduce the anxiety effect and concluded that apigenin’s sedative action may not come directly from benzodiazepine receptors. In rats, apigenin did not impair learning as diazepam did, and other, mostly unidentified compounds in chamomile also bind benzodiazepine and GABA receptors (all cited by EMA). A freeze-dried tea extract injected into mice reduced their activity and prolonged barbiturate-induced sleep. These were injected doses in rodents, so the animal work shows that a calming effect is biologically plausible rather than proving that a cup of tea sedates people.

What reaches you depends on the preparation. EMA explains that chamomile tea contains mainly flavonoids, their glycosides, and mucilage, but only about 10 to 15% of the essential oil constituents, depending on how it is brewed, although matricin and the coumarins do dissolve in hot water. Alcoholic extracts and tinctures capture more of the oil-soluble compounds, and steam-distilled oil is a different product again, made of volatile compounds such as bisabolol, chamazulene, farnesene, and spiroethers. The 2009 anxiety trial used an extract standardized to 1.2% apigenin, so its results cannot simply be assumed for tea. Two other laboratory findings explain safety warnings. Chamomile essential oil and its constituents inhibited the drug-metabolizing enzyme CYP1A2 and, less strongly, CYP3A4 in vitro (Ganzera and colleagues 2006, cited by EMA), and MSKCC adds inhibition of CYP2C9 and CYP2D6, with clinical relevance yet to be determined. NCCIH also notes that, according to preliminary studies, chamomile might have some of the same effects as estrogen.

Digestive complaints are chamomile’s core official use. EMA’s monograph accepts matricaria flower as a “traditional herbal medicinal product used for the symptomatic treatment of minor gastro-intestinal complaints such as bloating and minor spasms”, taken as a tea or as specified liquid extracts by mouth. Traditional status means EMA considers the use plausible and documented as safe for at least 30 years, including 15 in the EU, without proof from clinical trials. The supporting evidence EMA found was thin: an uncontrolled 1978 study in which 104 patients with nonspecific stomach complaints took a liquid extract four times a day for six weeks, after which 44% had no complaints. Germany’s Commission E had approved chamomile for gastrointestinal spasms and inflammation. No controlled trial has tested chamomile alone for indigestion, irritable bowel syndrome, or reflux, so a cup after a heavy meal is a reasonable traditional choice rather than a treatment for persistent symptoms. EMA advises seeing a doctor if symptoms last more than a week while using it.

EMA’s other four traditional indications involve use outside the gut. Chamomile infusion or diluted extract can be used as a gargle or mouth rinse for minor mouth ulcers and inflammation of the mouth and throat; as a steam inhalation to relieve symptoms of the common cold; as washes, compresses, partial baths, or ointments for minor skin inflammation such as sunburn, superficial wounds, and small boils; and, after a doctor has excluded serious disease, as an add-on for irritation of the skin and mucosa in the anal and genital region, for example as a sitz bath. These uses rest on long tradition and open, uncontrolled studies. For mouth sores caused by cancer treatment, NCCIH says small studies suggest chamomile mouthwashes might help and MSKCC calls the data mixed. In the largest placebo-controlled trial, 164 patients receiving 5-fluorouracil chemotherapy used a chamomile or placebo mouthwash three times a day for 14 days, with no difference in mouth sores (Fidler and colleagues, Cancer 1996). MSKCC also cites a controlled study in which chamomile compresses healed skin lesions around colostomies better than 1% hydrocortisone ointment.

Anxiety has the strongest human trials. Amsterdam and colleagues (Journal of Clinical Psychopharmacology 2009) randomized 57 adults with mild to moderate generalized anxiety disorder to placebo or a chamomile extract standardized to 1.2% apigenin, starting at one 220 mg capsule a day and rising to as many as five, for eight weeks. Anxiety scores fell significantly more with chamomile (P = 0.047), and the authors described the effect as modest. Mao and colleagues (Phytomedicine 2016) then gave 179 people with moderate to severe generalized anxiety disorder 1,500 mg of extract a day for 12 weeks, and randomized the 93 who responded to continue chamomile or switch to placebo for 26 weeks. Relapse occurred in 15.2% on chamomile and 25.5% on placebo, a difference that was not statistically significant, although symptoms stayed significantly lower with chamomile. An exploratory analysis by the same team suggested extra antidepressant effects in people who also had depression. NCCIH sums this up as preliminary evidence that a chamomile supplement might help generalized anxiety disorder and associated depression.

Sleep is chamomile’s most popular use, but the evidence is weaker and mixed. In the only trial in chronic insomnia, Zick and colleagues (BMC Complementary and Alternative Medicine 2011) gave 34 adults 270 mg of chamomile extract twice a day or placebo for 28 days and found no significant differences in sleep diary measures such as total sleep time and time to fall asleep. Trials measuring self-rated sleep quality look better. In 60 older adults in Iran, 200 mg capsules twice a day for four weeks improved sleep quality scores compared with dummy capsules in a single-blind trial (Adib-Hajbaghery and Mousavi 2017), and in 80 Taiwanese postnatal women with poor sleep, two weeks of chamomile tea improved sleep-related symptoms and depression scores compared with usual care, a benefit that had faded by four weeks (Chang and Chen 2016). Hieu and colleagues (Phytotherapy Research 2019) pooled 12 trials and found better sleep quality but no evidence for insomnia, and Kazemi and colleagues (Complementary Therapies in Medicine 2024) found a 1.88-point improvement on the Pittsburgh Sleep Quality Index across five trials, with very inconsistent results and no gain in sleep duration, sleep efficiency, or daytime functioning.

Other uses have little support. For period pain, a Cochrane review by Pattanittum and colleagues (2016) included German chamomile among 12 herbal medicines; its placebo-controlled data were unsuitable for analysis, and one trial of 160 women gave very limited, low-quality evidence that chamomile eased pain slightly more than anti-inflammatory painkillers (NSAIDs), by 1.42 points on a 10-point scale. For infant colic and childhood diarrhea, NCCIH notes that some combination products containing chamomile may help, but chamomile alone has not been shown to. In one trial, a tea of chamomile, vervain, licorice, fennel, and lemon balm eliminated colic in 19 of 33 infants, against 9 of 35 on placebo (Weizman and colleagues, Journal of Pediatrics 1993). MSKCC lists small positive trials of chamomile tea for blood sugar control in type 2 diabetes and of an extract for cyclic breast pain, which need confirmation, and notes that chamomile’s anti-inflammatory and anticancer properties come from laboratory and animal studies. None of this shows that chamomile prevents or treats cancer, diabetes, or any serious disease.

Tea is the standard form. EMA’s traditional dose for adults and adolescents with minor digestive complaints is 1.5 to 4 g of dried flowers infused in 150 ml of boiling water, three to four times a day; Commission E recommended about 3 g in 150 ml of hot water, covered for 5 to 10 minutes and drunk between meals. For children with digestive complaints, EMA gives 0.5 to 1 g two to four times a day from 6 months to 2 years, 1 to 1.5 g from 2 to 6 years, and 1.5 to 3 g from 6 to 12 years, and it does not set a dose under 6 months because of general considerations of nutrition and fluid intake. For colds, adults inhale the steam from 3 to 10 g of flowers in 100 ml of hot water; for the mouth and throat, 1 to 5 g in 100 ml of water is used as a rinse or gargle; and for skin washes and compresses, 3 to 10 g in 100 ml. Tea bags contain chamomile flower powder, pure or blended with other herbs (Srivastava and colleagues).

Liquid extracts and tinctures are made by soaking flowers in alcohol, usually mixed with water, and are labeled with a drug-to-extract ratio. EMA’s monograph lists fifteen accepted preparations, from cut flowers and alcoholic liquid extracts to dry extracts and ointments containing roughly 5.5 to 8% flower equivalent, each with its own dose: for example, 3 to 5 ml of certain liquid extracts in about 150 ml of water up to four times a day for digestive complaints, or 1 ml in 100 ml of water as a gargle. Products containing ethanol must say so on the label. Supplement capsules vary widely: the anxiety trials used 220 mg capsules of a standardized extract, up to 1,100 mg a day, and 1,500 mg a day, while the sleep trials used 200 to 270 mg twice a day. Chamomile essential oil is steam-distilled for aromatherapy, cosmetics, and bath products. EMA’s separate oil monograph accepts it only as a bath additive for irritated skin in the anal and genital region in people over 12, and it is not a product for swallowing.

Practical points: for occasional bloating or cramps, a freshly made cup of tea after meals is the traditional approach, and EMA advises seeing a doctor if symptoms persist beyond a week or get worse. For anxiety, the trial evidence applies to standardized extracts taken daily for several weeks, so an occasional bedtime cup is not equivalent, and ongoing anxiety deserves an assessment rather than self-treatment. Choose products that name Matricaria chamomilla or Matricaria recutita, because a label that says only “chamomile” may contain Roman chamomile. Buy from a reputable supplier: LactMed notes that botulism spores have been found in some loose-leaf chamomile teas sold in health food stores. Do not use homemade tea as an eye wash. Subiza and colleagues (Annals of Allergy 1990) described seven hay fever patients who developed allergic conjunctivitis, two with swollen eyelids, after bathing their eyes with chamomile tea, even though drinking it caused them no symptoms. Avoid layering several chamomile products, such as tea, capsules, and creams, which makes it harder to tell what caused a reaction.