Elderberry (Sambucus nigra) has a long history of use as a traditional remedy, commonly for colds and flu [1.4.4]. Its popularity is backed by its rich content of antioxidants, including flavonoids and vitamins [1.9.1]. However, its potent effects on the body mean it doesn't mix well with certain medications and isn't suitable for everyone. Before adding elderberry to your routine, it's essential to understand the potential risks.
The Science: Why Elderberry Interacts with Medications
The primary reason for elderberry's interactions is its effect on the immune system. Studies show that elderberry can increase the production of inflammatory cytokines, which are proteins that help regulate immune responses [1.5.2, 1.7.5]. While this immune boost can be helpful for fighting off viruses, it can be dangerous for individuals whose immune systems are already overactive or for those taking medications to suppress their immune function [1.7.4]. Additionally, elderberry may lower blood sugar levels and have a diuretic effect, creating further potential for interactions [1.4.2, 1.6.3].
Key Medications Not to Mix with Elderberry
Immunosuppressants
This is the most critical interaction. Because elderberry stimulates the immune system, it can directly counteract the effects of medications designed to suppress it [1.3.2, 1.5.1]. This is particularly dangerous for organ transplant recipients who rely on these drugs to prevent organ rejection [1.7.4]. It can also trigger flare-ups in people with autoimmune diseases [1.4.4].
Examples of immunosuppressants include:
- Azathioprine (Imuran) [1.3.2]
- Cyclosporine (Neoral, Sandimmune) [1.3.2]
- Tacrolimus (Prograf) [1.3.2]
- Mycophenolate (CellCept) [1.3.2]
- Corticosteroids like prednisone [1.3.2]
- Methotrexate [1.5.5]
Diabetes Medications
Elderberry may lower blood sugar levels [1.6.3]. When taken with diabetes medications like insulin or metformin, this can increase the risk of hypoglycemia (dangerously low blood sugar) [1.6.1, 1.6.2]. Symptoms of hypoglycemia include dizziness, confusion, shakiness, and weakness. If you have diabetes, you should not consume elderberry unless approved by your doctor [1.6.2].
Diuretics (Water Pills)
Elderberry itself can act as a natural diuretic, meaning it increases urination [1.4.2, 1.4.6]. Combining it with prescribed diuretics can lead to an excessive loss of fluids and electrolytes, potentially causing dehydration and other complications [1.4.2].
Other Potential Interactions
Some research suggests caution is also warranted with other medications, though the evidence may be less definitive:
- Theophylline: Used for respiratory diseases like asthma.
- Chemotherapy: Elderberry could potentially interact with cancer treatments [1.4.5].
- Pazopanib (Votrient): Taking elderberry with this cancer medication might increase the risk of liver side effects [1.3.5].
Comparison Table: Elderberry Drug Interactions
| Drug/Supplement Class | Mechanism of Interaction | Potential Outcome | Sources |
|---|---|---|---|
| Immunosuppressants | Elderberry stimulates the immune system, counteracting the drug's effect. | Decreased drug effectiveness, potential organ rejection, or autoimmune disease flare-ups. | [1.3.2, 1.5.1, 1.7.4] |
| Diabetes Medications | Elderberry may lower blood sugar, compounding the drug's effect. | Increased risk of hypoglycemia (low blood sugar). | [1.6.1, 1.6.2, 1.6.3] |
| Diuretics | Elderberry has its own diuretic effect, leading to a cumulative impact. | Dehydration and electrolyte imbalance from excessive fluid loss. | [1.4.2, 1.4.6] |
Who Should Avoid Elderberry?
Beyond medication interactions, certain groups should avoid elderberry due to a lack of safety data or specific health risks:
- Individuals with Autoimmune Diseases: People with conditions like rheumatoid arthritis (RA), multiple sclerosis (MS), or lupus (SLE) should avoid elderberry. Its immune-stimulating properties can worsen symptoms or trigger a flare-up [1.4.4, 1.7.2].
- Pregnant and Breastfeeding Women: There is not enough reliable information to know if elderberry is safe during pregnancy or while breastfeeding [1.8.1, 1.8.4]. Due to the lack of data, it is recommended to avoid it [1.8.3].
- Organ Transplant Recipients: As mentioned, these individuals take critical immunosuppressant medications, and elderberry can interfere with them [1.7.4].
- Children: While some products are marketed for children, there is a lack of safety data, especially for long-term use or for children under five [1.8.4]. It is crucial to consult a pediatrician.
A Note on Raw Elderberry
It is critically important to never consume raw or uncooked elderberries, leaves, stems, or seeds [1.4.1, 1.9.5]. These parts of the plant contain cyanide-producing glycosides, which are toxic and can cause nausea, vomiting, diarrhea, and in large amounts, more severe poisoning [1.9.3, 1.9.4]. Cooking the berries removes these toxic compounds, making them safe for consumption [1.9.2]. Always use products from a reputable source or ensure berries are thoroughly cooked.
Conclusion
While cooked elderberry can be a beneficial supplement for some, its powerful effects on the immune system and other bodily functions make it unsuitable for many. The most significant risk involves its interaction with immunosuppressants, but its effects on blood sugar and fluid balance are also important considerations. If you are taking any prescription medications—especially for autoimmune diseases, diabetes, or after an organ transplant—or if you are pregnant or breastfeeding, it is essential to consult with your healthcare provider before using any elderberry product.
For more information on herbal supplement safety, you can visit the National Center for Complementary and Integrative Health (NCCIH).
