When taken by mouth, boldo may cause abdominal pain, nausea, or vomiting. When applied to the skin, boldo may cause irritation. A rarely reported side effect of boldo includes liver toxicity (the volatile oil from the boldo leaf contains ascaridole, which is toxic to the liver).
Boldo can interact with some medications. It can increase the effects of warfarin and other blood-thinning medications or anticoagulants (e.g., clopidogrel, aspirin) and increase the risk of bleeding or bruising.
Boldo can increase the risk of liver damage caused by certain medications (e.g., amiodarone, atorvastatin, carbamazepine, ketoconazole, methotrexate) and herbal products (e.g., comfrey, pennyroyal oil). It can also increase lithium levels in the body. It may decrease the levels of a medication called tacrolimus and increase the risk of transplant rejection. If you are taking any of these medications or herbal products, talk to your health care provider before using boldo.
If your symptoms persist or worsen after taking boldo, you should consult your health care provider. You should also consult your health care provider before using boldo if you have impaired kidney or liver function, or a block in your bile duct, or if you need to use it for more than 4 weeks.
Boldo has blood thinning effects, so you should stop using it at least 2 weeks before surgery to reduce the risk of bleeding.
You should avoid taking boldo if you:
- are allergic to boldo, its components, or related plants in the monimiaceae family.
- are breast-feeding
- are pregnant
- drink alcohol
- have gallbladder disease
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.