Chamomile tea is made from dried flower heads of the chamomile plant, and it contains a surprisingly complex mix of active compounds. The most important are a group of plant chemicals called flavonoids (especially one called apigenin), essential oils that give the tea its distinctive smell, and smaller amounts of coumarins and mucilages. These aren’t just background chemicals. They’re the reason chamomile has been used medicinally for centuries, and they’re what modern studies focus on when testing the tea’s effects on sleep, inflammation, and anxiety.
The Two Species Behind the Tea
Most chamomile tea sold commercially comes from German chamomile, though Roman chamomile also appears on shelves. The two plants look similar but have noticeably different chemical profiles. German chamomile essential oil is rich in a compound called chamazulene (which gives the oil an unusual blue color) along with bisabolol oxides, both of which have antioxidant properties. Roman chamomile oil, by contrast, is dominated by esters like isobutyl angelate, giving it a sweeter, fruitier aroma.
In lab testing, German chamomile oil showed stronger antioxidant activity, reaching over 95% inhibition of free radicals at very low concentrations. Roman chamomile performed better for anti-inflammatory effects, matching the activity of prednisolone, a standard anti-inflammatory drug, in albumin denaturation tests. Both species contain flavonoids and essential oils, but the balance shifts depending on which one is in your cup. If the label just says “chamomile,” it’s almost always German chamomile.
Flavonoids: The Star Compounds
The flavonoids in chamomile are what most researchers care about, and the headliner is apigenin. This compound binds to certain receptors in the brain that promote calmness and sleepiness, which is the main reason chamomile tea has a reputation as a bedtime drink. Dried chamomile flowers contain roughly 0.7 mg of apigenin per gram of dried tissue, though this varies by cultivar and growing conditions.
Apigenin isn’t the only flavonoid present. Chamomile also contains luteolin, quercetin, and rutin. Luteolin and quercetin both act as antioxidants and have anti-inflammatory effects in the body. Rutin is known for supporting blood vessel health. Together, these flavonoids are water-soluble enough to transfer into your cup when you steep the flowers, though the amount you actually extract depends on steeping time, water temperature, and how finely the flowers are broken up.
Essential Oils and Terpenoids
Chamomile flowers contain between 0.24% and 1.9% essential oil by weight. That might sound tiny, but these oils are potent and carry much of chamomile’s distinctive smell and therapeutic activity. The major terpenoid compounds include chamazulene (which can make up over 60% of the oil in some extractions), matricin (the precursor molecule that breaks down into chamazulene during processing), and alpha-bisabolol, which has well-documented anti-inflammatory and skin-soothing properties.
There are also some unusual compounds called spiroethers in chamomile oil. These contain alkyne groups, a type of chemical bond that’s relatively rare in plant chemistry. Spiroethers have antispasmodic effects, meaning they help relax smooth muscle tissue. This is likely one reason chamomile tea has traditionally been used for stomach cramps and digestive discomfort.
Essential oils are less water-soluble than flavonoids, so a standard cup of tea captures only a fraction of what’s in the raw flower. Covering your mug while steeping helps trap volatile oils that would otherwise evaporate with the steam.
Coumarins and Other Minor Compounds
Chamomile contains small amounts of coumarins, primarily herniarin and umbelliferone, along with their sugar-bound forms (glycosides). Coumarins are plant compounds that can thin the blood at high doses. In a normal cup of tea, the coumarin content is low enough that bleeding complications have never been documented in humans. However, people taking blood-thinning medications like warfarin who drink chamomile tea extensively should be aware the potential for interaction exists, even though it remains theoretical.
The flowers also contain mucilages, gel-like carbohydrates that coat and soothe mucous membranes. These contribute to chamomile’s traditional use for sore throats and mild stomach irritation.
What Actually Ends Up in Your Cup
Brewing chamomile tea is really a selective extraction process. Hot water pulls out the water-soluble compounds first: flavonoids like apigenin and its glycosides, coumarins, mucilages, and some minerals. The longer you steep, the more of these compounds dissolve into the water. Most recommendations suggest 5 to 10 minutes of steeping with a cover on the cup.
The essential oils are harder to extract. They’re lipophilic, meaning they dissolve better in fats and oils than in water. You’ll get some into the tea, particularly the lighter, more volatile molecules, but a cup of chamomile tea contains far less essential oil than a chamomile supplement or tincture would. This is one reason clinical trials on chamomile and sleep tend to use concentrated extracts rather than tea. One insomnia study used doses equivalent to 7.5 grams of dried herb twice daily, standardized to deliver specific amounts of bisabolol and apigenin per dose. That’s considerably more than the 1 to 2 grams of flowers in a typical tea bag.
Caffeine and Calorie Content
Chamomile tea is naturally caffeine-free. Unlike green, black, or white tea, chamomile isn’t made from the Camellia sinensis plant, so it contains zero caffeine unless it’s been blended with true tea leaves. A plain cup also has essentially no calories, fat, or protein. There are trace minerals present, but not in amounts that contribute meaningfully to your daily intake.
German vs. Roman Chamomile in Practice
If you’re choosing between the two species, the differences matter most for concentrated products like essential oils. German chamomile oil offers stronger antioxidant protection and higher UV-protective potential (SPF values of 26 to 27 in lab testing, compared to 9 to 16 for Roman chamomile). Roman chamomile oil edges ahead for anti-inflammatory and skin-soothing applications, with a milder, more pleasant fragrance profile.
For everyday tea drinking, the distinction is less dramatic. Both species deliver flavonoids, terpenoids, and coumarins. German chamomile tends to taste slightly more herbaceous and apple-like, while Roman chamomile leans sweeter. The core active compounds, apigenin and bisabolol, are present in both.