TempoLife › Features › Herb and spice reference: evidence, dose and interactions
Herbs and spices
37 herbs and spices, each graded against what a European regulator actually accepted: the monograph indication, the form, how long it is meant to be used, side effects, and the medicines it interacts with.
This is a reference page, not a diagnosis and not a prescription. Herbal products are real pharmacology: they have effects, side effects and interactions with medicines. Tell your doctor and your pharmacist everything you take, including teas and supplements, and never stop or change a prescribed medicine because of anything you read here.
How the evidence grade is decided
Every entry gets one letter. The letter is ours; the regulatory status behind it is not. In the European Union a herbal medicinal product reaches the market by one of two routes, and which route it took tells you a great deal about what is known. Well-established use means the regulator assessed clinical evidence and accepted it. Traditional use means the product was registered on decades of use alone — no trials required, and the pack must say so. Products sold as food supplements have taken neither route and have been assessed for neither.
| Grade | What it means here | Entries |
|---|---|---|
| A — Recognised efficacy | A European Union herbal monograph carries a well-established-use indication for a defined preparation, meaning the regulator accepted clinical evidence. | 5 of 37 |
| B — Traditional use, trials point the same way | Registered on long-standing use, and independent reviews of human trials point in the same direction without settling the question. | 4 of 37 |
| C — Traditional use only | Plausible from thirty or more years of use, which is what a traditional-use registration means. No clinical evidence was required and none has settled it. | 21 of 37 |
| D — Popular claim unsupported, or safety dominates | The better trials are negative, or the substance appears in the literature mainly for the harm it has caused. | 7 of 37 |
Why there is no dose column
Almost every herb page on the internet prints a number of grams or milligrams. This one does not, and the reason is worth understanding before you read any of them. A herbal preparation is defined by three things together: the plant part, the extraction solvent, and the drug-to-extract ratio. Two grams of dried valerian root, two millilitres of a 1:5 tincture and one tablet of a 5:1 dry extract are not comparable quantities of anything. Printing a figure that came from one preparation next to a product made by another is not information, it is noise with a decimal point.
What can be published honestly is what monographs actually state in words: which preparation an indication applies to, and how long the product is meant to be used before you stop and ask someone. Both are on every page below. The dose is on the pack of the product in front of you, and a pharmacist will read it with you for free.
Five rules that prevent most herbal harm
- Tell your pharmacist and your doctor what you take. Not just prescriptions — teas, tinctures, capsules, everything. Most of the harm on this page happened because nobody knew.
- One new thing at a time. If something goes wrong on a stack of four supplements started the same week, nobody can tell which one did it, including you.
- Know the liver signs. Dark urine, yellowing of the eyes or skin, itching, unexplained tiredness, pain under the right ribs. Stop whatever you started and get seen. Several entries here carry that risk.
- Respect the duration limits. A stimulant laxative for a week is medicine; the same product every day for a year is a problem that gets worse the longer it runs.
- Symptoms that persist need a diagnosis, not a stronger herb. Urinary symptoms, headaches, indigestion and fatigue all overlap with conditions that are treatable when found and dangerous when not.
Every herb, by what it is used for
Search the table to find a herb by name, by local name, by what it is used for or by the medicine you take. The full list is below with or without the search box working.
Showing all 37 entries.
Sleep, stress and calm
The herbs bought for a bad night and a hard week — and what their registrations actually say.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Valerian palderjan (ET) · rohtovirmajuuri (FI) · валериана (RU) | Relief of mild nervous tension and to aid sleep. | C — Traditional use only | Alcohol, Sedatives, Surgery |
| Chamomile kummel (ET) · kamomilla (FI) · ромашка (RU) | Mild digestive complaints including bloating and flatulence; as a mouth rinse for minor inflammation of the mouth and throat; on the skin for minor irritation; as a steam inhalation for a cold. | C — Traditional use only | Anticoagulants, warfarin, Sedatives |
| Lavender lavendel (ET) · laventeli (FI) · лаванда (RU) | Relief of mild symptoms of mental stress and exhaustion, and to aid sleep; the oil is also registered as a bath additive. | C — Traditional use only | Sedatives, Alcohol |
| Lemon balm sidrunmeliss (ET) · sitruunamelissa (FI) · мелисса (RU) | Relief of mild symptoms of mental stress and to aid sleep; and, separately, mild digestive complaints including bloating and flatulence. | C — Traditional use only | Sedatives, Levothyroxine |
| Passionflower kannatuslill (ET) · kärsimyskukka (FI) · пассифлора (RU) | Relief of mild symptoms of mental stress and to aid sleep. | C — Traditional use only | Sedatives, Alcohol, Surgery |
Mind, mood and fatigue
Where the strongest efficacy evidence and the most dangerous interactions on this page both live.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| St John's wort naistepuna (ET) · mäkikuisma (FI) · зверобой (RU) | Mild to moderate depressive episodes, for particular standardised dry extracts; traditional-use preparations are also registered for temporary mental exhaustion and, externally, for minor wounds and skin inflammation. | A — Recognised efficacy | Contraceptives, Antidepressants, SSRIs, Anticoagulants, warfarin, Immunosuppressants, HIV medicines, Cancer treatment, Statins, Digoxin |
| Ginkgo hõlmikpuu (ET) · neidonhiuspuu (FI) · гинкго (RU) | Improvement of cognitive impairment and of quality of life in mild dementia, for a specific standardised leaf dry extract used under medical supervision. | A — Recognised efficacy | Anticoagulants, warfarin, NSAIDs, Epilepsy, Surgery |
| Ginseng (Panax) ženšenn (ET) · ginseng (FI) · женьшень (RU) | Symptoms of asthenia such as fatigue and weakness. | C — Traditional use only | Anticoagulants, warfarin, Diabetes medicines, MAOIs |
| Rhodiola (roseroot) roosijuur (ET) · ruusujuuri (FI) · родиола розовая (RU) | Temporary relief of symptoms of stress, such as fatigue and a sensation of weakness. | C — Traditional use only | Prescriptions |
| Ashwagandha ashwagandha (ET, FI) · ашваганда (RU) | Nothing a European regulator has assessed. It is marketed for stress, sleep, testosterone and athletic performance. | D — Popular claim unsupported, or safety dominates | Levothyroxine, Sedatives, Immunosuppressants, Liver load |
Digestion, bloating and the bowel
The largest group, and the one with the most well-established-use registrations.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Peppermint piparmünt (ET) · piparminttu (FI) · мята перечная (RU) | Symptomatic relief of minor spasms of the gastrointestinal tract, flatulence and abdominal pain, especially in irritable bowel syndrome, for gastro-resistant oil capsules; the leaf is registered for mild digestive complaints. | A — Recognised efficacy | Antacids, PPIs |
| Caraway köömen (ET) · kumina (FI) · тмин (RU) | Mild spasmodic gastrointestinal complaints including bloating and flatulence. | B — Traditional use, trials point the same way | No established medicine interactions |
| Ginger ingver (ET) · inkivääri (FI) · имбирь (RU) | Prevention of nausea and vomiting in motion sickness, and mild digestive complaints such as bloating. | B — Traditional use, trials point the same way | Anticoagulants, warfarin, Diabetes medicines |
| Fennel apteegitill (ET) · fenkoli (FI) · фенхель (RU) | Mild spasmodic gastrointestinal complaints including bloating and flatulence; and as an expectorant in cough associated with a cold. | C — Traditional use only | No established medicine interactions |
| Turmeric kurkum (ET) · kurkuma (FI) · куркума (RU) | Relief of digestive disturbances such as a feeling of fullness and flatulence. | C — Traditional use only | Anticoagulants, warfarin, Liver load |
| Liquorice lagrits (ET) · lakritsi (FI) · солодка (RU) | Digestive complaints including burning sensation and dyspepsia; and as an expectorant in cough associated with a cold. | C — Traditional use only | Blood pressure, Digoxin |
| Milk thistle maarjaohakas (ET) · maarianohdake (FI) · расторопша (RU) | Relief of digestive complaints, including a feeling of fullness and indigestion. | C — Traditional use only | Prescriptions, Diabetes medicines |
| Senna senna (ET, FI) · сенна (RU) | Short-term use in occasional constipation. | A — Recognised efficacy | Digoxin, Blood pressure, Absorption timing |
| Psyllium (ispaghula husk) psüllium (ET) · psyllium (FI) · псиллиум (RU) | Constipation, and conditions in which easy defecation with a soft stool is desirable; also used to increase dietary fibre intake. | A — Recognised efficacy | Absorption timing, Diabetes medicines, Levothyroxine |
| Aloe aaloe (ET) · aloe (FI) · алоэ (RU) | Short-term treatment of occasional constipation, for the dried leaf latex. | C — Traditional use only | Digoxin, Blood pressure, Absorption timing |
Colds, cough and throat
Short-course herbs for a self-limiting illness, and the point at which a cold stops being one.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Echinacea siilkübar (ET) · punahattu (FI) · эхинацея (RU) | Short-term prevention and treatment of the common cold. | C — Traditional use only | Immunosuppressants |
| Elder / elderberry must leeder (ET) · mustaselja (FI) · бузина чёрная (RU) | Relief of early symptoms of the common cold, for elderflower preparations. | C — Traditional use only | Immunosuppressants, Diabetes medicines |
| Thyme aed-liivatee (ET) · timjami (FI) · тимьян (RU) | As an expectorant in cough associated with a cold. | C — Traditional use only | No established medicine interactions |
| Sage salvei (ET) · salvia (FI) · шалфей (RU) | As a gargle or mouth rinse for minor inflammations of the mouth and throat; orally for mild dyspepsia and for excessive sweating. | C — Traditional use only | Epilepsy, Diabetes medicines |
Joints, urinary tract and hormones
Symptoms that overlap with conditions needing a diagnosis first.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Nettle nõges (ET) · nokkonen (FI) · крапива (RU) | Leaf: to increase the amount of urine and so flush the urinary tract in minor complaints, and for minor joint pain. Root: lower urinary tract symptoms related to benign enlargement of the prostate. | C — Traditional use only | Anticoagulants, warfarin, Blood pressure, Diabetes medicines |
| Saw palmetto | Relief of lower urinary tract symptoms related to benign prostatic hyperplasia, after a doctor has excluded serious conditions. | D — Popular claim unsupported, or safety dominates | Anticoagulants, warfarin, Prescriptions |
| Cranberry jõhvikas (ET) · karpalo (FI) · клюква (RU) | Reducing the chance of repeat urinary tract infections in some groups — not treating an infection that is already present. | B — Traditional use, trials point the same way | Anticoagulants, warfarin, Diabetes medicines |
| Black cohosh | Relief of menopausal complaints such as hot flushes and profuse sweating. | C — Traditional use only | Liver load, Cancer treatment |
| Devil's claw | Relief of minor joint pain, and of mild digestive complaints such as bloating and loss of appetite. | C — Traditional use only | NSAIDs, Anticoagulants, warfarin, Diabetes medicines |
| Feverfew | Prophylaxis of migraine headaches, after serious conditions have been excluded by a doctor. | C — Traditional use only | Anticoagulants, warfarin, NSAIDs |
Kitchen spices with a safety story
Everyday spices where a real European safety figure or a real toxicity exists.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Cinnamon kaneel (ET) · kaneli (FI) · корица (RU) | Nothing that survives a systematic review. It is a spice with a real safety figure attached. | D — Popular claim unsupported, or safety dominates | Diabetes medicines, Liver load, Anticoagulants, warfarin |
| Garlic küüslauk (ET) · valkosipuli (FI) · чеснок (RU) | Relief of symptoms of mild circulatory complaints, in traditional-use preparations. Not the treatment of cardiovascular disease. | C — Traditional use only | Anticoagulants, warfarin, HIV medicines, Surgery |
| Nutmeg muskaatpähkel (ET) · muskottipähkinä (FI) · мускатный орех (RU) | Nothing medicinal. It is on this list because it is the kitchen spice that poisons people. | D — Popular claim unsupported, or safety dominates | Prescriptions |
| Green tea extract roheline tee (ET) · vihreä tee (FI) · зелёный чай (RU) | Marketed for weight loss and metabolism. Neither claim survives review. | D — Popular claim unsupported, or safety dominates | Liver load, Iron, Anticoagulants, warfarin |
| Chilli and cayenne (capsaicin) tšillipipar (ET) · chili (FI) · кайенский перец (RU) | Topical relief of muscle and joint pain in low-strength preparations; high-concentration capsaicin patches are licensed medicines for peripheral neuropathic pain. | B — Traditional use, trials point the same way | Blood pressure, Prescriptions |
Where the harm is
Two botanicals included as boundaries rather than options.
| Herb | What the registration is for | Evidence | Watch with |
|---|---|---|---|
| Kava | It was marketed for anxiety. It is included here as a boundary, not a recommendation. | D — Popular claim unsupported, or safety dominates | Alcohol, Sedatives, Liver load |
| Comfrey varemerohi (ET) · rohtoraunioyrtti (FI) · окопник (RU) | External use on unbroken skin for bruises, sprains and strains, in pyrrolizidine-alkaloid-depleted preparations. | D — Popular claim unsupported, or safety dominates | Liver load |
Nothing matches that search. Try a plant name, a symptom, or the name of a medicine group.
Start from the medicine you take
This is the question people actually arrive with, so here it is from the other side. Each row is a medicine group and the herbs on this site that have something documented about it. Where a link is available, it goes to the medicine-side page in the medicine, food and alcohol interactions reference, which is organised by medicine rather than by plant.
Reading a herbal product label in a European pharmacy
Three kinds of product sit side by side on the same shelf and the packaging deliberately makes them look alike. A registered traditional herbal medicinal product carries a registration number, a named indication, and the sentence about long-standing use; its quality, its contamination limits and its leaflet have all been assessed. A herbal medicinal product with well-established use carries an indication supported by clinical evidence and is the closest thing on the shelf to a conventional medicine. A food supplement carries neither, may not claim to treat anything, and is regulated as food — which means the assessment behind it is about safety as a food, not efficacy as a treatment.
None of that makes a supplement useless or a registered product effective. It tells you what somebody checked, which is the only thing a label can honestly tell you from the outside.
What this reference deliberately leaves out
Vitamins, minerals, creatine and protein powders are not here: those are covered separately in the supplement reference, which is built on the NIH Office of Dietary Supplements fact sheets. This page is botanicals — whole plants and their preparations. Culinary entries link through to the food data for the same plant where the nutrition figures are useful, because a spice is also a food.
Also left out: any claim a monograph does not carry and a fact sheet does not support. If a herb is famous for something and the section on it is short, that gap is the finding.
Sources: European Medicines Agency — Committee on Herbal Medicinal Products (HMPC), European Union herbal monographs · NIH National Center for Complementary and Integrative Health — herb fact sheets · LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (NIDDK, National Institutes of Health) · European Food Safety Authority — scientific opinions on coumarin, green tea catechins and hydroxyanthracene derivatives · European Commission Scientific Committee on Food — opinion on glycyrrhizinic acid · checked 2026-09-06
Frequently asked questions
What does "traditional use" on a herbal pack mean?
It means the product was registered on the basis of long-standing use — at least thirty years, of which at least fifteen in the EU — and not on clinical trials. The pack has to say so: a traditional herbal medicinal product used exclusively on the basis of long-standing use. It is a real licence with real quality and safety requirements, and it is not a claim that trials showed the product works.
What is the difference between a herbal medicine and a food supplement?
A registered herbal medicinal product has an assessed quality, a defined preparation, an approved indication printed on the box and a leaflet listing interactions and contraindications. A food supplement has none of those things and may not legally claim to treat anything. Two capsules of the same plant can sit on adjacent shelves under completely different rules.
Why does this page not tell me how many grams to take?
Because a gram figure does not transfer between products. A tea, a tincture and a 10:1 dry extract of the same root contain wildly different amounts of the constituents that do the work, so a number lifted from a website is not a dose for the pack in your hand. The only correct dose is the one on that pack, or the one a pharmacist gives you.
Which herb has the most dangerous medicine interaction?
St John's wort, by a wide margin. It induces the CYP3A4 enzyme system and the P-glycoprotein transporter, which between them clear a large share of prescription medicines, so it lowers the blood levels of contraceptives, anticoagulants, transplant medicines, HIV treatment, statins and several cancer drugs. Contraceptive failure and transplant rejection have both been reported.
Are herbal products safe because they are natural?
No. The three clearest examples on this page are all natural: comfrey's pyrrolizidine alkaloids damage the liver, liquorice raises blood pressure and strips potassium, and nutmeg in quantity causes a genuine toxic syndrome. Natural describes where a molecule came from, not what it does.
Track what you take, alongside everything else
TempoLife keeps supplements, food, sleep and symptoms in one log — which is exactly the list a pharmacist asks for and nobody can ever remember.