Borage (Borago officinalis), also known as starflower, is a popular herb and dietary supplement prized for its high content of gamma-linolenic acid (GLA) in its seed oil. It is often used for its purported anti-inflammatory properties to address conditions like rheumatoid arthritis, eczema, and other skin disorders. However, like many herbal remedies, borage is not without risks and can pose significant interactions with certain medications. The key to understanding these interactions lies in two of its main components: GLA and potentially hepatotoxic pyrrolizidine alkaloids (PAs).
Key Drug Interactions with Borage
Borage and Anticoagulant/Antiplatelet Medications
One of the most critical drug interactions involves blood thinners. Borage seed oil contains GLA, which can inhibit platelet aggregation and prolong bleeding time. When taken alongside medications that also slow blood clotting, this effect can be compounded, significantly increasing the risk of bleeding and bruising.
Medications that interact with borage in this manner include:
- Anticoagulants: Such as warfarin (Coumadin), heparin, dalteparin, and enoxaparin.
- Antiplatelets: Such as clopidogrel (Plavix).
- Nonsteroidal anti-inflammatory drugs (NSAIDs): These include common over-the-counter and prescription pain relievers like aspirin, ibuprofen (Advil, Motrin), and naproxen (Aleve).
For anyone on these medications, it is crucial to avoid borage or consult a healthcare provider for monitoring. Increased vigilance for signs of bleeding, such as unusual bruising, nosebleeds, or blood in the urine or stool, is necessary.
The Risk of Liver Toxicity
A major safety concern with borage is the presence of pyrrolizidine alkaloids (PAs), which are toxic to the liver. While the concentration of PAs in borage oil is often low due to processing, long-term use or large doses can increase the risk of liver damage. This is particularly dangerous for individuals with pre-existing liver disease or those taking other hepatotoxic drugs.
Borage should not be combined with other medications known to cause liver damage, including:
- Anabolic steroids
- Phenothiazines
- Ketoconazole
Patients taking borage supplements should always ensure the product is certified and labeled PA-free to minimize this significant health risk. The risk of hepatic damage increases with both the length and cumulative dose of exposure.
Borage and Seizure Threshold
Several case reports have suggested a link between borage oil consumption and the lowering of the seizure threshold, even in individuals with no history of epilepsy. In one instance, a woman experienced status epilepticus after taking high doses of borage oil for a week. While some studies have reported conflicting results, the risk is enough to warrant caution, especially for individuals with seizure disorders or those taking medications that also affect seizure risk.
Patients on the following medications should be particularly cautious:
- Phenothiazines: A class of medications used to treat mental and emotional disorders, including chlorpromazine and fluphenazine.
- Tricyclic antidepressants: Another class of medication that can also lower the seizure threshold.
Interactions with Liver Enzyme Inducers (CYP3A4)
The liver enzyme CYP3A4 is responsible for breaking down many drugs. Some medications can increase the activity of this enzyme, and because the liver also metabolizes borage, this process can increase the toxic effects of the PAs found in borage seed oil.
Examples of CYP3A4 inducers that can enhance borage's toxicity include:
- Carbamazepine (Tegretol)
- Phenobarbital
- Phenytoin (Dilantin)
- Rifampin
Comparison of Borage and Evening Primrose Oil
Both borage and evening primrose oil are sources of GLA, but they differ in composition and potency, which can affect interaction profiles.
| Feature | Borage Oil | Evening Primrose Oil (EPO) |
|---|---|---|
| GLA Content | Higher (approx. 20–26%) | Lower (approx. 7–10%) |
| PAs Present | Potential risk of liver toxic pyrrolizidine alkaloids (PAs) | Generally considered PA-free and safer for liver concerns |
| Bleeding Risk | Higher bleeding risk due to higher GLA content | Lower bleeding risk compared to borage, though still a potential issue |
| Seizure Risk | Associated with reports of lowering seizure threshold | Fewer reports compared to borage, but some historical reports exist related to GLA |
Important Safety Precautions for Borage Use
To minimize the risk of adverse effects and interactions, it is crucial to follow safety guidelines.
- Choose Certified Products: Always opt for borage oil products that are certified PA-free. This significantly reduces the risk of liver toxicity.
- Disclose to Your Doctor: Inform your healthcare provider about all supplements, including borage, that you are taking. This is essential for preventing dangerous drug interactions.
- Avoid Before Surgery: Stop taking borage supplements at least two weeks before any scheduled surgical procedure to minimize the risk of excessive bleeding.
- Consult a Specialist for Pre-existing Conditions: If you have liver disease, a bleeding disorder, or a history of seizures, discuss the use of borage with a specialist before starting supplementation.
Conclusion
While borage is widely available as a natural supplement for conditions like inflammation and skin issues, its potential for serious interactions with prescription medications cannot be ignored. The compounds in borage, particularly GLA and PAs, can increase bleeding risk when combined with anticoagulants, pose a threat of liver toxicity, and potentially increase the risk of seizures when taken with certain drugs. The safest approach is to use only PA-free certified borage oil and, most importantly, to consult with a healthcare professional to ensure it is safe to use in conjunction with any current medications or health conditions. For more information on borage, including traditional uses and potential side effects, you can visit Memorial Sloan Kettering Cancer Center.
