| Name of herb | Intended use | Toxicity | Interaction with chemotherapeutics |
| Nettle | To strengthen immune system, prostate diseases, urinary system diseases, allergy, arthritis, and anti-inflammatory | Abdominal pain, diarrhea, fever, bleeding problems, gynecomastia, galactorrhea, and hypoglycemia | It may interact with cancer drugs, which metabolize where it affects cytochrome P450 enzyme system. |
| Garlic | Hypertension, hyperlipidemia, antineoplastic, antimicrobial | Bleeding problems | Its usage with dacarbazine should be avoided (CYP2E1 inhibition). |
| Green tea | In cancer prevention, prostate cancer, cardiac diseases, gastrointestinal diseases, for losing weight | Nausea, insomnia, diarrhea, confusion | While increasing the effect of drugs such as anthracycline, taxanes, and tamoxifen (CYP3A4 inhibition), it may decrease the effect of bortezomib by different interaction routes. |
| Ginkgo biloba (Ginkgo tree) | Antiemetic, antioxidant, pro-circulatory, dementia, tinnitus | Bleeding, allergy/hypersensitivity, stroke, headache | It interacts with numerous chemotherapy agents, including EGFR-TKI (CYP3A4 and CYP2C19 inhibition). |
| Echinacea (purple cone flower) | To strengthen immune system, common cold | Hypersensitivity (including anaphylaxis) | It interacts with numerous chemotherapy agents, including etoposide and EGFR-TKI (CYP3A4, CYP2C19, and CYP2D6 inhibition). |
| Soya products | Menopause symptoms, osteoporosis, cancer prevention | Meteorism, allergic reactions | It should not be used with tamoxifen in ER-positive breast cancer and in endometrial cancer. |
| Saw palmetto (Serenoa repens) | Benign prostate hypertrophy | Abdominal pain, nausea, vomiting, constipation or diarrhea, bleeding problems, emboli | No significant interaction has been reported. |
| Ginseng | Sedative, aphrodisiac, antidepressant, and diuretic | Nausea, diarrhea, euphoria, insomnia, headache, hypertension, hypotension, hypoglycemia, mastalgia, vaginal bleeding, and cerebral arteritis | It interacts with numerous chemotherapy agents, including EGFR-TKI (CYP3A4, CYP2C9 inhibition) and imatinib (could increase risk of hepatotoxicity); it should not be used in ER-positive breast cancer or in endometrial cancer. |
| St. John's wort (Tipton's weed, Hypericum perforatum) | Depression | Allergic dermal reactions, constipation, dry mouth, gastrointestinal disorder, dizziness, asthenia, and sleep disorder | It interacts with almost all chemotherapy agents, including BCR-ABL TKI, VEGF-TKI, EGFR-TKI, ALK inhibitors, the mTOR inhibitor everolimus, antiestrogens, aromatase inhibitors, the phosphatidylinositol 3-kinase inhibitor idelalisib, and the BRAF kinase inhibitor vemurafenib (CYP2B6, CYP2C9, CYP2C19, CYP2E1, CYP3A4, and P-glycoprotein induction). It also decreases level of active metabolite of irinotecan and cyclophosphamide plasma concentration. |
| Black cohosh (horseradish root) | Menopause symptoms, sedation | Dizziness, headache, nausea, vomiting | It affects CYP3A4 enzyme system. It increases the toxicity of doxorubicin and docetaxel. It increases the effect of tamoxifen. |
| Cranberry (blueberry, huckleberry) | Urinary tract infection | Bleeding problems | No significant interaction has been reported. |
| Valerian (Polemonium) | Sleep irregularities, stress | It may cause headache, restlessness, cardiac problems | It interacts with numerous chemotherapy agents (CYP2C9 inhibition, CYP2C19 induction). The ones using tamoxifen, cyclophosphamide, etoposide, and teniposide should be careful. |
| Milk thistle (Eryngium) | Hepatosteatosis, cirrhosis, cancer prevention | Laxative effect and menstrual stimulation | It causes doxorubicin metabolism to decrease by interacting with cytochrome P450 system. |
| Evening primrose (Oenothera biennis) | Menopausal symptoms, pain, neuropathy | Headache, nausea, and increasing risk of pregnancy complication | Since it binds to serum proteins and it may modify chemotherapy efficacy, its usage is not recommended. |
| Kava (stonecrop) | Anxiety, insomnia, stress | Stupor, vision disorders, dizziness, yellowing at skin and nail, fatal liver toxicity | It interacts with numerous chemotherapy agents and EGFR-TKI (CYP3A4 induction). |
| Bilberry (blueberry) Red grape seed | Diabetes retinopathy Allergic rhinitis, cancer prevention, hyperlipidemia | Bleeding problems No significant toxicity has been reported. | No significant interaction has been reported. It interacts with numerous chemotherapy agents and EGFR-TKI (CYP3A4 induction). |
| PC-SPES | Prostate cancer | Gynecomastia, loss of libido, gastric disorders, cramps, thrombus, diarrhea, cardiac problems, hot flush | Since it affects enzyme system in the liver, it may interact with many chemotherapeutics. It should not be used together with these. |
| Reishi mushroom (red reishi) | Allergy, arthritis, bronchitis, gastric ulcer, diabetes, hypertension, chronic hepatitis, nephritis, insomnia, scleroderma, and cancer | Nausea, vomiting, liver toxicity, and bleeding problems | Since it affects enzyme system in the liver (CYP2E1, CYP1A2, and CYP3A inhibition), it may interact with many chemotherapeutics. It should not be used together with these. |
| Oleander (rosebay) | Cancer treatment, cardiac failure, HIV, AIDS, rheumatoid arthritis, psoriasis | Abdominal pain, hypothermia, dizziness, respiratory paralysis, death | No significant interaction has been reported. |
| Essiac | Cancer treatment, health maintenance, support for immunity, HIV and AIDS | No significant toxicity has been reported | It interacts with chemotherapy drugs by inhibiting CYP3A. |
| Mistletoe (Iscum album) | Cancer treatment, immune stimulation, arthritis, sedation | Hepatotoxicity, anaphylactic shock | It interacts with chemotherapy drugs by CYP3A4 inhibition. |
| Licorice | Cancer treatment, gastroprotective, antiinflammatory, antiallergic | Hypokalemia (myopathy), hypertension, pulmonary edema, digoxin toxicity | It interacts with chemotherapy drugs by causing CYP3A induction. |
| Astragalus (wild licorice) | To strengthen immune system, diabetes, and cardiac diseases | No significant toxicity has been reported | It interacts with cyclophosphamide. |
| Ginger | In treatment of acute and delayed nausea developing due to chemotherapy | No significant toxicity has been reported | No significant interaction has been reported. |
| Curcuma | In colorectal cancer and leukemia | Nausea, gastric irritation, diarrhea, bleeding problems | It interacts with many drugs, mainly doxorubicin and cyclophosphamide. |
