INTERACTION CONCERNS WITH ST JOHN’S WORT?
Why this incredible herb isn’t always a safe choice
St John’s Wort has a long history of traditional use, dating all the way back to the ancient Greeks. A long-standing history like that is often encouraging—it points to general safety and well-documented effects.
But general safety isn’t the whole picture. When it comes to St John’s Wort (SJW), the major safety concern is medication interactions—and that’s what we’re diving into today.
So, are the interaction concerns with St John’s Wort valid?
Short answer: YES.
Longer answer: Let’s break it down.
It’s not entirely understood, but what we do know is that St John’s Wort affects certain liver enzymes involved in drug metabolism—especially CYP3A4, a key player in breaking down many medications. SJW upregulates these enzymes, meaning it can cause medications to be broken down faster (reducing their effectiveness), or occasionally more slowly (increasing their levels and potential side effects).
SJW can also amplify the effects of antidepressants, which might sound like a good thing… but this combination can actually be life-threatening. That’s because it increases the risk of a dangerous condition called Serotonin Syndrome, where serotonin levels become too high.
Medications SJW can decrease the effect of:
Antihistamines (anti-allergy medications)
Digoxin-containing medications (e.g. Lanoxin)
Immunosuppressants (e.g. Cyclosporine)
Antiretrovirals (e.g. HIV medications)
Oral contraceptives (aka “the Pill”)
Reserpine (used for high blood pressure)
Alprazolam (Xanax – for anxiety)
Theophylline (for asthma)
Warfarin (a blood-thinner)
Medications SJW can increase the effect or risk of side effects for:
Antidepressants (especially SSRIs)
Plavix (Clopidogrel) – a blood-thinner
Cough medicines with dextromethorphan
Sedatives (e.g. benzodiazepines)
Triptan migraine medications
This isn’t a complete list. The potential interactions are wide-ranging, which is why I only prescribe St John’s Wort for patients who are not taking medications. Fortunately, SJW is far from the only natural option for supporting mood and mental health.
Natural alternatives to SJW for mood support
There are many evidence-based, gentle alternatives that I use instead of SJW—especially when someone is on medication or at higher risk of interactions:
Vitamin B12
(This list isn’t exhaustive either—and the best option depends on your unique health picture.)
But herbs aren’t the whole picture…
In true naturopathic fashion, I want to help uncover the root cause of your mental health symptoms. The real question I ask is:
“What’s underneath your depression or anxiety?”
Sometimes it’s nutrient deficiencies. Sometimes it’s trauma, thyroid dysfunction, gut imbalances, blood sugar instability, or chronic stress. When we address the root cause, that’s when true healing becomes possible.
I’m not a fan of “band-aid” approaches—especially not for mental health. They might numb the symptoms, but they don’t fix the deeper problem. And you deserve better than that.
Why see a naturopath for your mental health?
When you work with me, you can expect:
A holistic, deep-diving approach
Guidance on targeted testing to uncover root causes
Referrals for functional testing (e.g. Hair Tissue Mineral Analysis, Full Microbiome Panel)
A highly personalised plan to transform your mental health
Strategies to support medication safety and reduce side-effects
A stronger connection to your body and your needs
Ready to transform your mental health story?
I only take on a small number of clients in this space to ensure they receive the focused support they deserve—especially if they’re working on reducing medication dependence (always in collaboration with their GP or prescribing specialist).
So if you’re ready to take the next step, reach out!
Let’s uncover the real story behind your symptoms and work together on a path to true healing.
AUTHOR: Talitha
I specialise in gut health (IBS, IBD, microbiome testing), women's health (preconception, fertility, hormone balance), and mental health (depression, stress, anxiety). I am a degree- qualified naturopath who LOVES helping people transform their health stories!!
