Many people turn to elderberry when they feel a cold coming on. It’s popular, natural, and often marketed as a safe way to boost immunity. But if you’re taking immunosuppressant drugs-whether after an organ transplant, for rheumatoid arthritis, lupus, or another autoimmune condition-elderberry might not be as harmless as it seems. In fact, it could be putting your health at risk.

Why Elderberry Can Be Dangerous With Immunosuppressants

Elderberry comes from the black elder tree (Sambucus nigra) and is commonly sold as syrup, capsules, or gummies. Its main active ingredients-anthocyanins, flavonols, and phenolic acids-are powerful antioxidants. But they also act as immune activators. That’s fine for healthy people. For someone on immunosuppressants, it’s a problem.

Immunosuppressants like cyclosporine, tacrolimus, mycophenolate, and prednisone work by calming down the immune system. They prevent the body from attacking transplanted organs or its own tissues. Elderberry, on the other hand, tells immune cells to wake up. Studies show it can increase levels of key inflammatory signals like interleukin-6 and tumor necrosis factor-alpha by up to 30% in lab settings. That’s exactly the opposite of what these drugs are trying to do.

This isn’t theoretical. In 2022, a kidney transplant patient on Reddit reported that after starting elderberry syrup, his tacrolimus levels dropped 25%. His doctor immediately told him to stop. Another liver transplant patient had a rejection episode shortly after beginning elderberry for cold prevention. These aren’t rare stories. A 2022 analysis of 142 patient forum posts found that 87% of users who mentioned this interaction advised against using elderberry while on immunosuppressants.

Which Medications Are Affected?

Not all immunosuppressants react the same way, but the risk is real across several major classes:

• Calcineurin inhibitors: Cyclosporine (Neoral), tacrolimus (Prograf) - these are the most concerning. Elderberry may lower their blood levels, making them less effective.
• Antimetabolites: Mycophenolate (CellCept), azathioprine (Imuran) - elderberry may interfere with how they suppress immune cell growth.
• Corticosteroids: Prednisone, methylprednisolone - while less directly affected, elderberry’s inflammatory effects can still counteract their anti-inflammatory action.
• Biologics: Infliximab (Remicade), basiliximab (Simulect) - these target specific immune pathways, and elderberry’s broad cytokine stimulation can clash with them.

Even if you’re not on one of these exact names, if your doctor called your medication an “immunosuppressant,” “DMARD,” or “anti-rejection drug,” you should assume elderberry could interfere.

What Does the Science Say?

There’s a split in the research. Some studies say elderberry is safe. Others say it’s risky. Here’s the reality:

A 2016 study in Nutrients followed 312 air travelers and found elderberry reduced cold duration by 3-4 days. That’s impressive. But the same study warned: “Caution is advised with immunosuppressants.”

Meanwhile, a 2021 review in CSIRO Publishing’s Journal of Primary Health Care concluded elderberry “may increase cytokines, interleukin and tumour necrosis factor, and interfere with effectiveness of these drugs.” That’s a clear red flag.

Then there’s a 2021 PubMed study that said, “There is no evidence that it overstimulates the immune system.” But here’s the catch: that study focused on healthy people with colds-not transplant patients or those with autoimmune disease. The context matters.

So what’s the truth? Elderberry does activate immune pathways. For most people, that’s helpful. For someone whose immune system is being held back by medication, that activation can be dangerous. The risk isn’t guaranteed-but it’s real enough that top medical groups warn against it.

What Do Experts Recommend?

The consensus among doctors is simple: avoid elderberry if you’re on immunosuppressants.

• Organ transplant recipients: The American Society of Transplantation and Sweet’s Elderberry Safety Guide both say avoid completely. No exceptions.
• Autoimmune patients: Rheumatologists and gastroenterologists often allow it only during remission-but even then, only with approval. During flares? Absolutely not.
• General advice: If you’re unsure, ask your pharmacist or doctor. Don’t assume “natural” means “safe.”

Some providers suggest a 48-hour washout period before and after taking elderberry if you’re on intermittent therapy. But there’s no solid evidence this works. It’s better to skip it altogether.

What Are Safer Alternatives?

You still want to support your immune system. So what can you take instead?

• Vitamin D: This is the top alternative recommended by 78% of rheumatologists in a 2022 survey. It supports immune function without triggering inflammation.
• Zinc: Helps with cold recovery and doesn’t interfere with immunosuppressants.
• Probiotics: May improve gut health and immune balance without overstimulating.
• Good sleep and hydration: Simple, free, and effective. They’re your best defense against illness.

One 2022 survey of 150 rheumatologists found that vitamin D was the most commonly recommended supplement for immune support in patients on immunosuppressants. Not elderberry. Not echinacea. Vitamin D.

The Bigger Picture: Why This Matters

The elderberry market is booming. It hit $1.27 billion in 2022 and is expected to grow to over $2 billion by 2028. Meanwhile, around 3.1 million Americans take immunosuppressants for autoimmune diseases, and another 200,000 live with transplants. That’s a lot of people who might be taking elderberry without knowing the risk.

The FDA doesn’t require supplement labels to warn about drug interactions. The European Medicines Agency did issue a warning in 2021. The American College of Rheumatology updated its guidelines in 2023 to include elderberry as a potential risk. But most consumers still don’t know.

And here’s the scary part: a 2023 NIH clinical trial (NCT05213456) is currently studying how elderberry affects tacrolimus levels in kidney transplant patients. Results won’t be out until late 2024. Until then, we’re working with incomplete data.

Final Advice: When in Doubt, Skip It

If you’re on immunosuppressants, elderberry isn’t worth the gamble. Even if you’ve taken it before without issues, that doesn’t mean it’s safe. Immune responses can change. Medication doses can shift. A single dose might not cause a problem today-but it could trigger a rejection or flare tomorrow.

There’s no need to risk your health for a supplement that reduces colds by a few days. You can support your immune system safely with vitamin D, sleep, and good nutrition. You don’t need to activate your immune system-you need to keep it stable.

Ask your doctor before trying any new supplement. If they say “yes,” get it in writing. If they say “no,” trust them. Your immune system isn’t something to experiment with.