Safety Warnings for St. John’s Wort

Safety Warnings for St. John’s Wort

Including the Dangers of Using St. John’s Wort to Treat Bipolar Depression

I mentioned last week that St. John’s wort has been shown ineffective at treating mild depression as well as moderately severe depression (major depression).

Nevertheless, St. John’s wort is the most well-known alternative treatment for depression and many people take it. However, there are absolutely some dangers in taking St. John’s Wort that you should know about, especially if you’re bipolar.

Warning – the following is information provided by me, a non-doctor. Please check all information out with an actual doctor if you’re at all concerned. Thanks.

St. John’s Wort is not “Safe”

One of the problems with herbal remedies is that people think they are “safe” because they are “natural.” Well, so’s lithium and I wouldn’t recommend chomping on that without a doctor’s supervision either.

Herbs do things. If they didn’t, people wouldn’t take them. St. John’s wort may not be FDA-regulated (a whole other problem) but it is, for all intents and purposes, a drug. This means it should be treated with the same caution as any other drug.

St. John’s Wort and Bipolar Depression

St. John’s wort is 100% contraindicated in cases of bipolar depression because it can cause mania or hypomania. I repeat, do not take St. John’s wort if you have bipolar depression. Clear? OK then.

I suspect it can also induce mixed moods and cycling, but I saw no specific literature to that effect.

Why Can’t St. John’s Wort be Taken with Bipolar Disorder?

Warnings About St. John's Wort for Depression

St. John’s wort works in numerous ways and because it’s an herb and not synthesized, it’s sort of tough to say exactly how St. John’s wort works and why. It is thought St. John’s wort activates the serotonergic, noradrenergic, and dopaminergic systems and by activating gamma-aminobutyric acid (GABA) and glutamic acid receptors in the brain (more).

That is similar to how prescription antidepressants work.

In other words, St. John’s wort can intensify the effect of an antidepressant, which isn’t a good thing without medical supervision and is never a good thing for a person with bipolar disorder.

Also, too much serotonin in the brain can cause serotonin syndrome (in anyone), which is potentially life-threatening. (Particularly relevant if taking St. John’s Wort with other serotonin-altering drugs.)

St. John’s Wort and Other Medications

St. John’s wort should not be taken with other medications without first checking with a doctor. This is because St. John’s wort has been shown to interact with (among others):

  • Antidepressants
  • Birth control
  • Immunosuppressants
  • HIV medication
  • Heart medication
  • Cancer medication
  • Seizure medication

It has even been linked to organ rejection in transplant patients.

Regulation of St. John’s Wort

There isn’t any.

St. John’s wort is considered a dietary supplement and was on the market before the Dietary Supplement Health and Education Act (DSHEA) of 1994 and so is not required to supply any safety or efficacy data.

Moreover, dietary supplement manufacturers in the USA also include or omit safety information on product labels at their own discretion.


People hate the pharmaceutical companies? Well, check this:

St. John’s Wort Safety Labeling

Perhaps the worst news of all is how incredibly bad St. John’s wort manufacturers are at labeling their own products. In a study of 74 St. John’s wort products from the US only 4% included safety information on seven-out-of-eight safety criteria.

The eight safety criteria that should have been labeled were regarding St. John’s wort and:

  1. HIV medication interaction
  2. Immunosuppressant drug interaction
  3. Interactions with oral contraceptives
  4. Interaction with Warfarin
  5. Interactions with antidepressants
  6. Contraindications for use with bipolar disorder
  7. Phototoxicity
  8. Advice to contact a health professional

Zero of the 74 products listed these eight things, and quite frankly, many of those interactions could kill you. In case you were wondering, the rates of labeling St. John’s wort products were the following:

  1. HIV medication interaction – 8.1%
  2. Immunosuppressant drug interaction – 5.4%
  3. Interactions with oral contraceptives – 8.1%
  4. Interaction with Warfarin – 5.4%
  5. Interactions with antidepressants – 23%
  6. Contraindications for use with bipolar disorder – 1.4%
  7. Phototoxicity – 51.4%
  8. Advice to contact a health professional – 87.8%

So, apparently it’s important to tell people they might get a sunburn but not that their heart medication might not work. Peachy.

Other Warnings about St. John’s Wort

Warning with Bipolar and St. John's Wort

Images from Wikipedia

And, just in case you were wondering, Canada, the UK (great fact sheet) and the US have put out warnings on St. John’s wort and medication interactions. The FDA sent out a public advisory in 2000 and some doctors are highly skeptical about the benefits of St. John’s wort.

Oh, and your doctor or pharmacist likely doesn’t know this stuff, with one study showing considerably more than half of doctors didn’t know about St. John’s wort interactions with warfarin, digoxin and oral contraceptives. About half of pharmacists weren’t aware of St. John’s wort’s interaction with cyclosporine and one-third were unaware of the interaction with oral contraceptives. Oral contraceptives mixed with other medications can lead to complications. has information about yaz side effects as well as other birth control methods.

St. John’s Wort is Like a Box of Chocolates

You Never Know What You’re Going to Get

And in addition to all that, which ticks me off quite enough thank you, there is the issue of non-regulation. Because St. John’s wort isn’t regulated you never really know what you’re buying. People say to simply buy from a “reputable” brand, but given the nonexistent safety labelling I’m not sure I feel any of them are terribly reputable.

[Quick caveat: St. John’s wort is used in Europe, I gather, fairly successfully, but the difference is they treat it like a drug. They use a standard product, dosages and issue prescriptions. It’s a far cry from whatever gets labeled as St. John’s wort here.]


About Natasha Tracy

Natasha Tracy is an award-winning writer, speaker and consultant from the Pacific Northwest. She has been living with bipolar disorder for 18 years and has written more than 1000 articles on the subject.

Natasha’s New Book

Find more of Natasha’s work in her new book: Lost Marbles: Insights into My Life with Depression & Bipolar. Media inquiries can be emailed here.

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