Understanding Angelica Root and Its Uses
Angelica root refers to the root of plants from the Angelica genus, most notably Angelica sinensis (commonly known as Dong Quai) and Angelica archangelica [1.2.2, 1.9.2]. Used for centuries in traditional Chinese medicine, Dong Quai is often taken for menstrual and menopausal issues [1.11.3]. It is believed to enrich the blood, promote circulation, and modulate the immune system [1.5.3]. The root contains various active compounds, including volatile oils, coumarins, and ferulic acid, which contribute to its purported therapeutic effects but also to its potential for drug interactions [1.2.4, 1.4.1]. Due to these active constituents, it is critical to consider how it may affect conventional medications.
The Major Risk: Interaction with Blood Thinners
The most well-documented and dangerous interaction is between angelica root and medications that slow blood clotting (anticoagulants and antiplatelet drugs) [1.6.2].
- Anticoagulants: Drugs like warfarin (Coumadin) are prescribed to prevent blood clots. Angelica root also has blood-thinning properties because it contains coumarin derivatives [1.4.1, 1.6.4]. Taking them together significantly increases the risk of bruising and potentially life-threatening bleeding [1.2.2, 1.4.3]. Anyone on warfarin should avoid angelica root unless explicitly approved and monitored by their healthcare provider [1.6.4].
- Antiplatelet Drugs: Medications such as aspirin and clopidogrel work by preventing blood platelets from sticking together. Combining these with angelica root can amplify the antiplatelet effect, heightening the risk of bleeding [1.6.5].
- Other Herbs: The risk is further compounded if taken with other supplements that affect blood clotting, such as garlic, ginger, ginkgo, and Panax ginseng [1.3.1, 1.3.5].
Metabolic and Hormonal Interactions
Beyond blood thinners, angelica root can interact with medications through several other mechanisms, including effects on liver enzymes and hormonal activity.
Interference with Drug Metabolism (Cytochrome P450 Enzymes)
Many species in the Angelica genus, including A. archangelica and A. dahurica, contain compounds called furanocoumarins [1.2.1, 1.2.2]. These are the same substances found in grapefruit that are known to interfere with drug metabolism [1.3.3]. They can inhibit cytochrome P450 (CYP450) enzymes in the liver and intestines, particularly the CYP3A4 enzyme [1.7.1].
This is significant because the CYP3A4 enzyme is responsible for breaking down more than 50% of clinically used drugs [1.7.1]. By inhibiting this enzyme, angelica root can cause these medications to build up in the body, leading to increased side effects or toxicity. Medications that carry a "grapefruit warning" are particularly susceptible, including certain cholesterol-lowering drugs (statins) and anti-seizure medications [1.2.2, 1.3.3]. Studies on A. dahurica have shown it can inhibit various CYP enzymes, including CYP3A, CYP2C, and CYP2D, affecting the metabolism of probe drugs like midazolam and tolbutamide [1.7.1, 1.7.2].
Hormonal Interactions
Angelica sinensis may act like the hormone estrogen in the body [1.6.2]. This means it can interfere with:
- Hormone Replacement Therapy (HRT): Taking dong quai with HRT might increase the side effects of estrogen [1.3.1].
- Birth Control Pills: Its estrogenic effect could potentially alter the effectiveness of oral contraceptives [1.3.2].
- Hormone-Sensitive Conditions: Individuals with conditions worsened by estrogen, such as certain types of breast cancer, should avoid using it [1.9.2].
Other Potential Medication Interactions
While research is ongoing, there are other theoretical and observed interactions to be aware of:
- Blood Pressure Medications: The effects of angelica root on blood pressure are complex. Some research suggests certain species may have a relaxing effect on blood vessels, which could lower blood pressure and magnify the effect of hypotensive drugs [1.2.3, 1.5.2]. Conversely, there are also reports that A. sinensis may increase blood pressure in some cases, which could counteract the effects of antihypertensive medications [1.2.2, 1.5.4].
- NSAIDs: Nonsteroidal anti-inflammatory drugs like ibuprofen and naproxen can have a mild blood-thinning effect. Combining them with angelica root could theoretically increase the risk of bleeding [1.3.2].
| Feature | Angelica Root (A. sinensis) | St. John's Wort (Hypericum perforatum) |
|---|---|---|
| Primary Interaction Mechanism | Antiplatelet/anticoagulant effects; CYP enzyme inhibition (furanocoumarins) [1.2.1, 1.2.2]. | Potent induction of CYP3A4 and P-glycoprotein [1.8.1]. |
| Effect on Drug Levels | May increase levels of drugs metabolized by inhibited CYP enzymes [1.7.1]. | Typically decreases levels and effectiveness of many drugs [1.8.1]. |
| Key Interacting Drugs | Warfarin, antiplatelet drugs, drugs with grapefruit warnings, hormone therapies [1.2.1, 1.3.3]. | Antidepressants, birth control pills, cyclosporine, digoxin, HIV medications, warfarin [1.8.1]. |
| Main Clinical Risk | Increased risk of bleeding; increased drug toxicity [1.2.2]. | Treatment failure (e.g., unwanted pregnancy, organ transplant rejection); serotonin syndrome. |
Conclusion: Prioritize Safety and Medical Advice
Angelica root, particularly Angelica sinensis (Dong Quai), interacts with several types of medications, posing significant health risks. The most critical interaction is with blood thinners like warfarin, which can lead to dangerous bleeding [1.2.2, 1.4.3]. Its ability to inhibit liver enzymes means it can alter the levels of many common medications, similar to the well-known grapefruit effect [1.3.3]. Furthermore, its potential hormonal effects make it unsuitable for use with hormone therapies or for individuals with hormone-sensitive conditions [1.9.2].
Given the lack of standardized dosing and the seriousness of these potential interactions, it is essential to avoid self-treating with angelica root [1.2.2]. Always consult a healthcare provider or pharmacist before taking this or any herbal supplement, especially if you are on any prescription medications. It is recommended to stop taking angelica root at least two weeks before any scheduled surgery to minimize bleeding risk [1.9.2].
For more information on Dong Quai, you can visit the National Cancer Institute's page.
