“Herbal tea” sounds like one category. Scientifically, it is not.
Chamomile, peppermint, ginger, hibiscus and passionflower come from different plants, contain different compounds, have different evidence, and can carry different safety concerns. Putting them all under a single “healthy tea” label makes it too easy to turn tradition into a medical promise.
A better guide treats each herb as its own question.
This article looks at 10 common herbal infusions, what human research does and does not support, and when an ingredient deserves extra caution.
The short answer
Herbal infusions can be flavorful, caffeine-free additions to a normal beverage routine. Some herbs have promising human evidence for specific outcomes, while others have little direct research in tea form.
The biggest rules are simple:
- do not assume a traditional use is proven treatment
- do not assume extract or capsule studies apply directly to brewed tea
- do not assume “natural” means free of medication interactions or pregnancy concerns
- do not combine unrelated herbs into a single miracle-benefit story
Choose herbal tea first for flavor, culture and routine. Let evidence inform any health discussion without turning the cup into medicine.
Herbal tea is not true tea
Green, black, white and oolong tea all come from Camellia sinensis.
Herbal teas — more accurately called herbal infusions or tisanes — come from other plants. They may use flowers, leaves, roots, bark, seeds or fruit.
Many are naturally caffeine-free, but blends can include green tea, black tea, yerba mate, guarana or added caffeine. Check the ingredient list if caffeine matters to you.
For true-tea basics, see How to Brew Tea Better: Temperature, Time, Ratio & Water.
1. Chamomile
Why people drink it: mild floral flavor and an evening ritual.
Chamomile is one of the most familiar “calming” herbs, but the clinical evidence is much less dramatic than the marketing.
The National Center for Complementary and Integrative Health says some preliminary research suggests chamomile dietary supplements may help generalized anxiety disorder, but findings are not conclusive. Evidence for insomnia is sparse.
That distinction matters because many studies use standardized extracts rather than an ordinary cup of tea.
Safety notes
Chamomile is generally considered safe in amounts commonly found in tea and food. Allergic reactions can occur, especially in people sensitive to ragweed, chrysanthemums, marigolds or daisies.
NCCIH also notes reported or theoretical interactions with medicines including warfarin and sedatives.
Practical takeaway: enjoy chamomile as a caffeine-free evening drink if it agrees with you; do not treat it as proven anxiety or insomnia therapy.
2. Peppermint
Why people drink it: bright mint flavor and a caffeine-free finish after meals.
Peppermint is a good example of why product form matters.
Research on peppermint oil, especially enteric-coated capsules, is much stronger than research on peppermint leaf tea. NCCIH says there is not enough evidence to determine whether peppermint leaf is useful for any health condition.
That means an IBS study using peppermint-oil capsules should not be converted into “peppermint tea treats digestion.”
Peppermint tea itself appears safe for most adults, although long-term safety of very large amounts of peppermint leaf has not been well studied.
Practical takeaway: choose peppermint tea for flavor and a caffeine-free routine, not because capsule evidence proves the tea has the same clinical effect.
3. Ginger
Why people drink it: spicy warmth, especially when they want a stronger herbal cup.
Ginger has meaningful human research, but again, most clinical studies do not simply test a casual mug of ginger tea.
NCCIH notes evidence that ginger supplements may help nausea and vomiting associated with pregnancy and may reduce menstrual-cramp severity. Evidence is less certain for several other promoted uses.
Ginger can cause abdominal discomfort, heartburn, diarrhea, or mouth and throat irritation in some people.
Practical takeaway: ginger tea can be an enjoyable spicy beverage, but do not assume every supplement trial establishes an exact tea dose or effect.
4. Hibiscus
Why people drink it: tart, berry-like flavor and a vivid red color, hot or iced.
Hibiscus has more human trial evidence than many herbal infusions.
Multiple systematic reviews and meta-analyses of randomized trials have reported reductions in blood pressure among some participants consuming Hibiscus sabdariffa preparations, especially when baseline blood pressure was elevated. A 2025 overview of reviews and updated meta-analysis continued to find blood-pressure effects, while also calling for attention to therapeutic dosing and long-term safety.
That is interesting evidence. It still does not make hibiscus tea a replacement for antihypertensive medication or medical care.
If you take blood-pressure medicine and consume hibiscus frequently in amounts intended for a therapeutic effect, discuss that routine with your care team.
Practical takeaway: hibiscus is a flavorful caffeine-free drink with a real research signal around blood pressure, but it should not be self-prescribed as hypertension treatment.
5. Rooibos
Why people drink it: naturally caffeine-free, full-bodied, lightly sweet or woody flavor.
Rooibos comes from Aspalathus linearis, a South African plant.
It is frequently marketed around antioxidants, blood sugar, heart health and longevity. Human clinical evidence, however, is not strong enough to support sweeping treatment claims.
Some often-cited research on rooibos and metabolic health comes from animal or laboratory models. Those studies can be useful for generating hypotheses, but they do not prove that drinking rooibos prevents or treats diabetes in people.
Practical takeaway: the strongest everyday reason to choose rooibos is straightforward — it is naturally caffeine-free and tastes different from true tea. It does not need a miracle claim to earn a place in the cupboard.
6. Lemon balm
Why people drink it: soft lemon-herbal flavor, often in evening or relaxation blends.
A systematic review and meta-analysis of clinical trials found possible improvements in anxiety and depressive-symptom scores with lemon balm preparations.
But the studies used different preparations, doses and populations, and they do not establish that a typical lemon-balm tea reliably treats anxiety or depression.
This is another place where “promising clinical research” and “your cup will have the same effect” are not the same statement.
Practical takeaway: lemon balm can be a pleasant caffeine-free infusion. Treat mood claims cautiously unless the exact preparation and evidence match.
7. Passionflower
Why people drink it: it appears in many nighttime and “calm” blends.
NCCIH says a small amount of research suggests oral passionflower might reduce some anxiety symptoms and might improve total sleep time in adults with insomnia, but conclusions are not definite.
Passionflower can cause drowsiness, dizziness and confusion. It may interact with anesthesia and other medications used around surgery.
NCCIH also advises against passionflower during pregnancy because it may induce uterine contractions.
Practical takeaway: passionflower has limited preliminary evidence, not a strong enough base for anxiety or sleep-treatment claims. Its safety profile deserves more respect than a generic “calming herb” label suggests.
