---
title: "Herb–Drug Interactions & Safety Matrix | Herbadex"
description: "Searchable reference matrix of known herb-drug interactions, pregnancy status, minimum age limits and safety warnings."
language: en
url: https://herbadex.com/en/safety-matrix/
source: Herbadex (https://herbadex.com)
---

Herbadex

# Herb–Drug Interactions & Safety Matrix

Known drug interactions, pregnancy/breastfeeding status, minimum age limits and external-only warnings from published monographs.

Search herb or medicine (e.g. warfarin, antidepressant, blood pressure)...

SeverityPregnancy

123 herbs

| All herbs | Strongest evidence | Pregnancy | Breastfeeding | Children | Drug interactions |
| --- | --- | --- | --- | --- | --- |
| Alder Buckthorn Bark Frangula alnus | A Strong clinical evidence | Avoid | Avoid | Avoid | Major Cardiac glycosides (e.g. digoxin), antiarrhythmics, QT-prolonging medicines: Low potassium from long-term use can increase their effects; ask a doctor first.Moderate Diuretics, corticosteroids, liquorice root: May increase potassium loss; ask a doctor first. |
| Allspice Pimenta dioica | T Traditional use | Generally safe | Generally safe | Generally safe | Minor Anticoagulants (large amounts): Eugenol may affect platelets; does not apply to food amounts. |
| Anise Pimpinella anisum | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Argan Oil Argania spinosa | C Laboratory / animal evidence | Generally safe | Generally safe | Caution | No recorded interactions |
| Arnica Arnica montana ⚠ External use only | T Traditional use | Avoid | Unknown | Avoid | No recorded interactions |
| Artichoke Leaf Cynara cardunculus (syn. C. scolymus) | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Basil Ocimum basilicum | T Traditional use | Caution | Caution | Caution | Minor Warfarin: Very high intakes may reduce its effect because of vitamin K; keep daily intake steady. |
| Bay Leaf Laurus nobilis | T Traditional use | Caution | Caution | Caution | Minor Diabetes medicines: Large amounts may affect blood sugar.Minor Sedatives: Large amounts may add to drowsiness (theoretical). |
| Birch Leaf Betula pendula, Betula pubescens | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Bitter Melon in Olive Oil Momordica charantia | B Limited clinical evidence | Avoid | Avoid | Avoid | Major Diabetes medicines and insulin: May further lower blood sugar and cause hypoglycaemia. |
| Black Mulberry Syrup Morus nigra | T Traditional use | Generally safe | Generally safe | Caution | No recorded interactions |
| Black Pepper Piper nigrum | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | Moderate High-dose piperine supplements with phenytoin, propranolol, theophylline, ciclosporin: May raise drug levels; does not apply to food amounts. |
| Black Seed Nigella sativa | B Limited clinical evidence | Caution | Caution | Caution | Moderate Diabetes medicines: May further lower blood sugar.Minor Blood pressure medicines: May further lower blood pressure.Minor Anticoagulants: High doses could theoretically raise bleeding risk. |
| Black Seed Oil Nigella sativa | B Limited clinical evidence | Avoid | Caution | Caution | Moderate Diabetes medicines: May further lower blood sugar.Minor Anticoagulants: Could theoretically raise bleeding risk.Minor Blood pressure medicines: May further lower blood pressure. |
| Black Tea Camellia sinensis | A Strong clinical evidence | Caution | Caution | Caution | Moderate Iron supplements: Reduces absorption; leave 1–2 hours apart.Minor Other caffeinated products, stimulant drugs: Caffeine effects may add up.Minor Lithium, clozapine, theophylline: Caffeine may affect their levels. |
| Blue Anemone Flower Anemone spp. ⚠ External use only | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Broadleaf Plantain Plantago major | T Traditional use | Avoid | Avoid | Caution | Minor Medicines taken at the same time: Mucilage may delay absorption; leave 30–60 minutes apart. |
| Buckthorn Seed Rhamnus cathartica | T Traditional use | Avoid | Avoid | Avoid | Major Cardiac glycosides (e.g. digoxin), antiarrhythmics: Low potassium can increase their effects and side effects.Moderate Diuretics, corticosteroids, liquorice root: May increase potassium loss. |
| Cajun Seasoning Capsicum annuum, Piper nigrum, Allium sativum | T Traditional use | Generally safe | Generally safe | Caution | No recorded interactions |
| Calendula Calendula officinalis ⚠ External use only | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Cardamom Elettaria cardamomum | T Traditional use | Generally safe | Generally safe | Caution | No recorded interactions |
| Castor Oil Ricinus communis | A Strong clinical evidence | Avoid | Avoid | Avoid | Moderate Cardiac glycosides, diuretics: Potassium loss increases interaction risk.Minor All oral medicines: Rapid gut transit may reduce absorption. |
| Centaury Centaurium erythraea | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Chamomile Matricaria recutita | T Traditional use | Generally safe | Generally safe | Caution | Moderate Medicines taken after organ transplantation: Interactions via liver enzymes (CYP450) were reported with long-term, high-dose oral use. |
| Chasteberry Seed Vitex agnus-castus | A Strong clinical evidence | Avoid | Avoid | Avoid | Moderate Dopamine agonists and antagonists, oestrogens and anti-oestrogens: Interactions cannot be excluded because of possible dopamine-like and oestrogenic effects; ask a doctor first. |
| Chebulic Myrobalan Terminalia chebula | T Traditional use | Avoid | Avoid | Avoid | Minor Iron supplements and medicines taken at the same time: Tannins may reduce absorption; leave 2 hours apart.Minor Diabetes medicines: Lowered blood sugar in animal studies. |
| Cherry Stem Prunus avium | T Traditional use | Avoid | Avoid | Avoid | Moderate Diuretic medicines, lithium: May affect fluid and salt balance. |
| Cinnamon Cinnamomum verum | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Clove Syzygium aromaticum | T Traditional use | Generally safe | Generally safe | Caution | Minor Anticoagulants (large amounts): Eugenol may affect platelets; does not apply to food amounts. |
| Clove Oil Syzygium aromaticum ⚠ External use only | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Coconut Oil Cocos nucifera | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Coriander Coriandrum sativum | T Traditional use | Generally safe | Generally safe | Generally safe | Minor Diabetes medicines (concentrated extract): May further lower blood sugar (animal data). |
| Corn Silk Zea mays | T Traditional use | Avoid | Avoid | Avoid | Moderate Diuretic medicines, lithium: May affect fluid and salt balance.Minor Diabetes and blood pressure medicines: Lowered blood sugar and blood pressure in animal studies. |
| Costus Root Saussurea costus | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Couch Grass Elymus repens | T Traditional use | Avoid | Avoid | Avoid | Moderate Diuretic medicines, lithium: May affect fluid and salt balance; ask a doctor before combining. |
| Cubeb Pepper Piper cubeba | T Traditional use | Avoid | Caution | Caution | No recorded interactions |
| Cumin Cuminum cyminum | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | Minor Diabetes medicines (concentrated extract): May further lower blood sugar. |
| Curry Powder Curcuma longa, Coriandrum sativum, Cuminum cyminum, Trigonella foenum-graecum | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Dandelion Leaf Taraxacum officinale | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Devil's Claw Harpagophytum procumbens, H. zeyheri | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Echinacea Echinacea purpurea | A Strong clinical evidence | Avoid | Avoid | Avoid | No recorded interactions |
| Elderflower Sambucus nigra | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Eleuthero Eleutherococcus senticosus | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Eucalyptus Oil Eucalyptus globulus ⚠ External use only | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Fennel Foeniculum vulgare | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Fenugreek Trigonella foenum-graecum | T Traditional use | Avoid | Avoid | Avoid | Moderate Diabetes medicines: Monitor blood sugar closely because of a possible blood-sugar-lowering effect. |
| Ferula Root Water Ferula spp. | C Laboratory / animal evidence | Avoid | Avoid | Avoid | Moderate Drugs such as sildenafil, tadalafil and nitrates: Possible added effect on blood pressure; do not combine.Moderate Anticoagulants: Its coumarins could theoretically increase bleeding risk. |
| Flaxseed Linum usitatissimum | A Strong clinical evidence | Avoid | Avoid | Avoid | Moderate Other oral medicines: Absorption may be delayed; leave at least 30–60 minutes between them and flaxseed.Moderate Medicines that slow the bowel (e.g. opioids, loperamide): Use together only under medical supervision because of the risk of bowel obstruction. |
| Frankincense (Olibanum) Boswellia sacra / Boswellia serrata | B Limited clinical evidence | Avoid | Avoid | Avoid | Moderate Anticoagulants (e.g. warfarin): Limited data suggest it may increase bleeding risk; ask a doctor before combining. |
| Fumitory Fumaria officinalis | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Garlic Allium sativum | T Traditional use | Avoid | Avoid | Avoid | Moderate Anticoagulants and antiplatelet medicines (e.g. warfarin, clopidogrel): May prolong bleeding time; use with care and with your doctor's knowledge.Major Saquinavir/ritonavir (HIV medicines): May lower drug levels and cause loss of effect; must not be used together. |
| Ginger Zingiber officinale | A Strong clinical evidence | Avoid | Avoid | Caution | No recorded interactions |
| Ginkgo Leaf Ginkgo biloba | A Strong clinical evidence | Avoid | Avoid | Avoid | Major Anticoagulants (e.g. warfarin) and antiplatelet drugs (e.g. clopidogrel, aspirin, other NSAIDs): Their effect may change and bleeding risk may rise; medical monitoring needed.Major Efavirenz (HIV medicine): Its levels may fall; combined use is not recommended.Moderate Dabigatran: Levels may rise via gut P-glycoprotein inhibition; use with caution.Moderate Nifedipine: Levels may rise; dizziness and hot flushes may get worse. |
| Green Clay Montmorillonite / Illite (mineral) ⚠ External use only | C Laboratory / animal evidence | Caution | Caution | Caution | Major All medicines, if swallowed: Clay binds medicines and blocks their absorption. |
| Green Tea Camellia sinensis | T Traditional use | Avoid | Avoid | Avoid | Moderate Sedative medicines: Caffeine may reduce the effect of sedatives.Moderate Sympathomimetic medicines (e.g. some decongestants): Caffeine may increase their side effects. |
| Hawthorn Crataegus spp. | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Heather Leaf Calluna vulgaris / Erica spp. | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Hibiscus Hibiscus sabdariffa | B Limited clinical evidence | Avoid | Caution | Caution | Moderate Blood pressure medicines: May further lower blood pressure.Minor Hydrochlorothiazide: May change its effect; ask a doctor before combining.Minor Chloroquine (malaria drug): May reduce its absorption. |
| Hops Humulus lupulus | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Horse Chestnut Aesculus hippocastanum | A Strong clinical evidence | Avoid | Avoid | Avoid | No recorded interactions |
| Horsetail Equisetum arvense | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Isot Pepper Capsicum annuum | T Traditional use | Generally safe | Caution | Caution | No recorded interactions |
| Isparta Rose Water Rosa damascena | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Ivy Leaf Hedera helix | A Strong clinical evidence | Avoid | Avoid | Caution | No recorded interactions |
| Korean Ginseng Panax ginseng | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Lady's Mantle Alchemilla vulgaris | T Traditional use | Avoid | Avoid | Caution | Minor Iron supplements and medicines taken at the same time: Tannins may reduce absorption; leave 2 hours apart. |
| Lavender Lavandula angustifolia | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Lavender Oil Lavandula angustifolia ⚠ External use only | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Lemon Balm Melissa officinalis | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Licorice Root Glycyrrhiza glabra | T Traditional use | Avoid | Avoid | Avoid | Major Diuretics, cardiac glycosides (e.g. digoxin), corticosteroids, stimulant laxatives (e.g. senna): May increase potassium loss and electrolyte imbalance; do not combine.Moderate Blood pressure medicines: May reduce their blood-pressure-lowering effect.Moderate Medicines broken down by CYP3A4 (e.g. midazolam, omeprazole): May slightly lower their blood levels; take care when combining. |
| Linden Tilia cordata, Tilia platyphyllos | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Mahlab Prunus mahaleb | T Traditional use | Generally safe | Generally safe | Generally safe | Minor Warfarin (large amounts): Its coumarin could theoretically interact; does not apply to food amounts. |
| Marshmallow Root Althaea officinalis | T Traditional use | Avoid | Avoid | Caution | Minor Other oral medicines: Absorption may be delayed; leave at least 30–60 minutes between them and marshmallow root. |
| Mastic Gum Pistacia lentiscus | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Milk Thistle Silybum marianum | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Mint Mentha × piperita | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Mustard Seed Brassica spp. / Sinapis alba | T Traditional use | Caution | Caution | Avoid | No recorded interactions |
| Nutmeg Myristica fragrans | T Traditional use | Avoid | Caution | Avoid | Moderate Sedatives and psychiatric medicines: Nervous system effects may increase at high amounts. |
| Okra Seed Abelmoschus esculentus | C Laboratory / animal evidence | Caution | Caution | Caution | Minor Diabetes medicines: May further lower blood sugar (animal data).Minor Metformin: Okra mucilage reduced metformin absorption in animals; do not take at the same time. |
| Passion Flower Passiflora incarnata | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Pelargonium Root Pelargonium sidoides, Pelargonium reniforme | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Peppermint Oil Mentha × piperita | A Strong clinical evidence | Avoid | Avoid | Avoid | Minor Acid-reducing medicines (antacids, H2 blockers, proton pump inhibitors) and food: Can dissolve the capsule coating too early; do not take at the same time. |
| Pine Cone Syrup Pinus spp. | T Traditional use | Caution | Caution | Caution | No recorded interactions |
| Poppy Seed Papaver somniferum | C Laboratory / animal evidence | Generally safe | Generally safe | Caution | No recorded interactions |
| Psyllium Husk Plantago ovata | A Strong clinical evidence | Caution | Caution | Caution | Moderate Minerals, vitamin B12, heart glycosides (e.g. digoxin), coumarin anticoagulants, carbamazepine, lithium: Absorption may be delayed; leave at least 30–60 minutes between them and psyllium.Moderate Diabetes medicines: Diabetes treatment may need adjusting; use only under medical supervision.Moderate Thyroid hormones: The thyroid hormone dose may need adjusting; use under medical supervision.Moderate Medicines that slow the bowel (e.g. opioids): Use together only under medical supervision because of the risk of bowel obstruction. |
| Pumpkin Seed Cucurbita pepo | T Traditional use | Caution | Caution | Avoid | No recorded interactions |
| Red Pepper Flakes Capsicum annuum | A Strong clinical evidence | Generally safe | Caution | Caution | No recorded interactions |
| Rhodiola Rhodiola rosea | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Ribwort Plantain Plantago lanceolata | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Rose Hip Rosa canina | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | Minor Warfarin (high doses): High-dose vitamin C may alter its effect.Minor Lithium: Its diuretic effect may affect lithium excretion. |
| Rose Oil Rosa damascena ⚠ External use only | B Limited clinical evidence | Caution | Caution | Caution | No recorded interactions |
| Rosemary Salvia rosmarinus (syn. Rosmarinus officinalis) | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Saffron Crocus sativus | B Limited clinical evidence | Avoid | Caution | Avoid | Moderate Antidepressants: Possible added effect; ask a doctor before combining.Minor Blood pressure medicines and anticoagulants: High doses may lower blood pressure and increase bleeding. |
| Sage Salvia officinalis | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Sandy Everlasting Helichrysum arenarium | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Saw Palmetto Serenoa repens | A Strong clinical evidence | Unknown | Unknown | Avoid | Moderate Warfarin: Raised INR has been reported in a few cases; monitor INR closely. |
| Senna Senna alexandrina | A Strong clinical evidence | Avoid | Avoid | Avoid | Major Cardiac glycosides (e.g. digoxin), antiarrhythmics, QT-prolonging medicines: Low potassium from long-term use can increase their effects; ask a doctor first.Moderate Diuretics, corticosteroids, liquorice root: May increase potassium loss; ask a doctor first. |
| Sesame Sesamum indicum | B Limited clinical evidence | Generally safe | Generally safe | Caution | Minor Blood pressure and diabetes medicines: Large amounts may further lower blood pressure and blood sugar. |
| Small-Flowered Willowherb Epilobium parviflorum | T Traditional use | Unknown | Unknown | Avoid | No recorded interactions |
| Spanish Lavender Lavandula stoechas | T Traditional use | Avoid | Avoid | Avoid | Moderate Sedatives and sleeping pills: May add to drowsiness. |
| Spirulina Powder Arthrospira platensis | B Limited clinical evidence | Caution | Caution | Caution | Moderate Immunosuppressants: May reduce their effect by stimulating immunity.Minor Anticoagulants: Could theoretically raise bleeding risk. |
| St. John's Wort Hypericum perforatum | A Strong clinical evidence | Avoid | Avoid | Avoid | Major Birth control pills and other hormonal contraceptives: Lowers their levels and can cause breakthrough bleeding and reduced protection; use an extra method.Major Coumarin anticoagulants (e.g. warfarin), ciclosporin, tacrolimus, everolimus, sirolimus: Lowers their blood levels; combined use is contraindicated.Major HIV medicines (protease inhibitors, nucleoside reverse transcriptase inhibitors) and some cancer drugs (e.g. irinotecan, imatinib): Reduces their effect; combined use is contraindicated.Major Antidepressants (e.g. sertraline, paroxetine) and buspirone: Risk of serotonin syndrome (sweating, fast heartbeat, fever, agitation, tremor); do not combine.Moderate Alprazolam, diazepam, midazolam, methadone, simvastatin, digoxin, amitriptyline and other drugs broken down by CYP enzymes: Their levels may fall; ask a doctor first if you take prescription medicines. |
| St. John's Wort Oil Hypericum perforatum ⚠ External use only | T Traditional use | Avoid | Avoid | Caution | No recorded interactions |
| Stinging Nettle Urtica dioica, Urtica urens | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Sumac Rhus coriaria | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | Minor Diabetes medicines: May further lower blood sugar. |
| Sweet Almond Oil Prunus dulcis | B Limited clinical evidence | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Tea Tree Oil Melaleuca alternifolia ⚠ External use only | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Terebinth Berry Pistacia terebinthus | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Terebinth Soap Pistacia terebinthus ⚠ External use only | T Traditional use | Generally safe | Generally safe | Caution | No recorded interactions |
| Thyme Thymus vulgaris, Thymus zygis | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Thyme Oil Thymus vulgaris | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Tonka Bean Dipteryx odorata | T Traditional use | Avoid | Avoid | Avoid | Moderate Anticoagulants (e.g. warfarin): Coumarin carries a theoretical interaction risk.Moderate Liver-stressing medicines (e.g. high-dose paracetamol, some statins): May increase the risk of liver damage. |
| Tribulus Tribulus terrestris | B Limited clinical evidence | Avoid | Avoid | Avoid | Moderate Diabetes medicines: May lower blood sugar; monitor it.Moderate Blood pressure medicines, lithium: May lower blood pressure; may affect lithium excretion. |
| Turmeric Curcuma longa | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Valerian Root Valeriana officinalis | A Strong clinical evidence | Avoid | Avoid | Avoid | No recorded interactions |
| Vanilla Bean Vanilla planifolia | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Vine Leaf Vitis vinifera | A Strong clinical evidence | Avoid | Avoid | Avoid | No recorded interactions |
| Willow Bark Salix spp. | A Strong clinical evidence | Avoid | Avoid | Avoid | Major Anticoagulants (e.g. coumarin derivatives such as warfarin): May increase the effect of anticoagulants; do not combine without medical advice.Moderate Aspirin and other painkillers (NSAIDs): Combined use is not recommended without medical advice. |
| Witch Hazel Hamamelis virginiana ⚠ External use only | T Traditional use | Unknown | Unknown | Caution | No recorded interactions |
| Yarrow Achillea millefolium | T Traditional use | Avoid | Avoid | Avoid | No recorded interactions |
| Yedi Turlu Spice Blend Piper nigrum, Pimenta dioica, Cinnamomum verum, Syzygium aromaticum, Myristica fragrans, Zingiber officinale, Elettaria cardamomum | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |
| Yerba Mate Ilex paraguariensis | T Traditional use | Avoid | Avoid | Avoid | Moderate MAO-inhibitor antidepressants: Use with caution.Moderate Sedatives and sympathomimetic medicines: Caffeine may reduce the effect of sedatives and increase side effects of sympathomimetics. |
| Za'atar Thymbra spicata, Rhus coriaria, Sesamum indicum | T Traditional use | Generally safe | Generally safe | Generally safe | No recorded interactions |

This page is for information only and is not medical advice. If you take medication, are pregnant, or have a health condition, talk to your doctor or pharmacist before use.