Peppermint and Chamomile Tea

Herbal teas, or tisanes, are infusions of plants other than Camellia sinensis. Strictly speaking they are not tea, and most contain no caffeine [1]. Their evidence is mixed: the strong peppermint data are for oil capsules in irritable bowel syndrome (IBS), and chamomile shows small, inconsistent effects on sleep [2][3].

This guide covers what the research shows for peppermint and chamomile, the safety cautions for each, a few other common tisanes, and how to steep dried herbs. Bracketed numbers point to the References at the end.

Peppermint and Digestion

Peppermint (Mentha × piperita) leaf contains an essential oil that is mostly menthol and menthone, plus polyphenols such as rosmarinic acid and eriocitrin [4]. Menthol relaxes the smooth muscle of the gut, probably by blocking calcium channels, and may also dull gut pain signals [5].

The strongest evidence is for enteric-coated peppermint oil capsules in IBS. A meta-analysis of 12 trials with 835 patients found that the oil more than doubled the chance of overall symptom improvement compared with placebo [6]. The American College of Gastroenterology recommends it for IBS [2].

Peppermint leaf tea has no clinical trials of its own. A review found no trials of the tea itself and no reported adverse reactions to it [4]. The US National Center for Complementary and Integrative Health (NCCIH) says the tea appears safe but there is not enough evidence that it helps any condition [2]. The European Medicines Agency recognizes it as a traditional remedy for indigestion and flatulence, at 1.5 to 3 g of leaf in 100 to 150 mL of boiling water up to three times a day for adults [7].

People with gastroesophageal reflux should avoid peppermint, since it may worsen heartburn. Care is also advised with gallstones [7].

Chamomile and Sleep

The chamomile used for tea is usually German chamomile (Matricaria recutita). Roman chamomile (Chamaemelum nobile) is a different, low-growing perennial [8]. Chamomile's best-studied compound is apigenin, which is concentrated in the white ray florets [8]. In lab and mouse studies, apigenin binds the brain's benzodiazepine receptor and reduces anxiety without sedation [9]. Human trials have mostly used concentrated extracts.

The sleep evidence is small and mixed:

Study	Who and what	Result
Hieu et al. 2019, meta-analysis of 12 trials	Mostly extracts	Sleep quality improved; anxiety measures mixed [10]
Chang and Chen 2016	80 postnatal women; one cup of tea a day for 2 weeks vs usual care	Better sleep and mood at 2 weeks; no difference by 4 weeks [11]
Zick et al. 2011	34 adults with chronic insomnia; 270 mg extract twice daily for 28 days	No significant change in sleep [12]
Adib-Hajbaghery and Mousavi 2017	60 older adults; 400 mg extract daily for 28 days	Better sleep quality score [13]

NCCIH concludes that the evidence is too limited to rate chamomile for sleep [3]. Evidence for mild generalized anxiety is somewhat stronger, again with extracts: in one 8-week trial, response rates were 57% on chamomile and 38% on placebo [14].

Chamomile is likely safe in the amounts found in tea [3]. That makes it a low-risk part of a bedtime routine, with the understanding that any direct effect on sleep appears modest.

Safety cautions:

Allergy. People allergic to ragweed, chrysanthemums, marigolds, or daisies have a higher risk of reaction, and severe reactions have been reported [3][15].
Blood thinners. A woman on warfarin who drank four to five cups a day and used a chamomile lotion developed serious bleeding [16]. NCCIH lists interactions with warfarin and some liver-metabolized drugs [3].
Pregnancy. Safety in pregnancy and breastfeeding is not established [3].

Other Common Tisanes

Herb	What the evidence shows
Ginger	May ease nausea in pregnancy; uncertain for other nausea; most studies used supplements [17]
Lemon balm	Reduced anxiety in a small meta-analysis, with few trials and high variability [18]
Valerian	Inconsistent for sleep; a US sleep medicine guideline recommends against it for chronic insomnia [19]
Rooibos	Caffeine-free; small, inconsistent studies on blood lipids and glucose [20]

Safety and Preparation

Herbal teas can carry contaminants. Germany's food safety agency found pyrrolizidine alkaloids, plant toxins that can harm the liver, in 87% of chamomile and 86% of peppermint samples, probably from weeds harvested with the crop [21]. Its advice is to vary the herbal teas you drink [21]. Any herb can also interact with medicines [1].

Dried herbs need hot water and longer steeping than true tea. Health Canada's monograph for chamomile gives 3 g of dried flower heads in 150 mL of boiling water, steeped 5 to 10 minutes [22]. The EMA gives similar amounts for both chamomile and peppermint [7][15]. In one study, steeping peppermint 10 minutes extracted more polyphenols than 6 minutes, and storing leaf exposed to air and light lowered its menthol [23]. Tea bags with finely cut herbs hold less essential oil than whole leaf [24].

Steeping Herbal Tea With Tea Timer

Tea Timer's herbal preset uses boiling water and a 6-minute steep, and any blend can be saved with its own time and temperature. A chime sounds when the cup is ready.

Time your next herbal tea