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?

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.
Arg.
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:
- HIV medication interaction
- Immunosuppressant drug interaction
- Interactions with oral contraceptives
- Interaction with Warfarin
- Interactions with antidepressants
- Contraindications for use with bipolar disorder
- Phototoxicity
- 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:
- HIV medication interaction – 8.1%
- Immunosuppressant drug interaction – 5.4%
- Interactions with oral contraceptives – 8.1%
- Interaction with Warfarin – 5.4%
- Interactions with antidepressants – 23%
- Contraindications for use with bipolar disorder – 1.4%
- Phototoxicity – 51.4%
- 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
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.
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.]


Teresa - December 11, 2012 ←
I also point out that if you have a massage be sure to let the masseuse know not to include St. Johns Wort in the oil preparation, or any tincture that is made up for you.
Elaine Jones - May 23, 2012 ←
Great post and so important to get these warnings out there. I tried this when it was the popular “safe” way to help depression. Well of course it did not work and I had a bad reaction to it. I just took it w/o asking my doctor …. big mistake .. huge.
Natasha Tracy - May 23, 2012 ←
Hi Elaine,
I think many people have had that experience but for some reason you don’t normally hear about it. Probably because it’s “natural” no one thinks to mention it.
- Natasha Tracy
Kim - April 10, 2012 ←
I have BP 2. I decided to try St. Johns Wort as I was very depressed and feeling desperate. I became delusional and thought i was demonically possessed, tried contacting churches for an exorcism but was ignored. When I stopped taking it, the delusions stopped and have never returned.
Natasha Tracy - April 11, 2012 ←
Hi Kim,
I’m sorry to hear that happened to you but thank-you for sharing that experience so that others can learn from it.
- Natasha Tracy
Pam - January 31, 2012 ←
Very interesting…….Great job in the warning….Thank you.
Pam
Natasha Tracy - January 31, 2012 ←
Pam,
Yup, no problem. Just happy to get the information out there.
- Natasha
Emma Cooper - August 27, 2011 ←
Hi Natasha, thanks for the great research and thorough consideration of the counter indications for St John’s Wart, in particular the issues relating to lack of regulation. We have similar problems here in Australia with wide circulation, limited regulation and few warnings. Good to get some facts based on credible sources. Emma
Natasha Tracy - August 27, 2011 ←
Hi Emma,
The lack of regulation really gets me because it can be so dangerous to take these substances when you don’t know what you’re doing. And they’re just sitting there on the drug store shelves next to the toothpaste seemingly innocuous.
Canada is trying to take steps to improve the problem but I’m not quire sure how far we’ve come. Something is better than nothing though. I know you now have to at least be part of a formal national registry.
“Good to get some facts based on credible sources.”
I agree. St. John’s wort is actually a well-studied herb so there’s no excuse for not publicising honest information. I just wish more people did it than just talk about old wives tales and cite no sources.
- Natasha Tracy
Maurya - August 26, 2011 ←
Fasciniting stuff. So much great info, I’m bipolar, rapid cycling, and it’s my first time commenting but I’ve been a long time reader. Your website has been so informative and has changed my outlook on several subjects concerning mental health. Have you heard about a supplemnt called L-Theanine, Natasha? My therapist recommended it to calm my mild anxiety episodes. I’d be interested to hear your take on it.
Natasha Tracy - August 26, 2011 ←
Hi Maurya,
Great question. Never heard of it. It’ll make next week’s three new things :)
I did some research, here’s what we know:
- It’s derived from green tea, we’re not even sure the best way to do it
- It has been studied on mice and it seems to exert antipsychotic, possibly antidepressant-like properties http://www.ncbi.nlm.nih.gov/pubmed/21861094
- It’s a glutamate derivative and this is one of the new chemicals we’re targeting for mood disorder treatment (I’ve said before, I think it will become important in the next 10 years)
- There is very little research to suggest it is good for anything (animal research not being necessarily relevant, mice are not humans) http://www.rxlist.com/theanine/supplements.htm
- It is listed as a possible stress reducer, but again, with little to no evidence: http://www.umm.edu/altmed/articles/stress-000158.htm
- May, possibly improve cognitive impairment: http://www.ncbi.nlm.nih.gov/pubmed/21303262 (human study)
Keep in mind, whenever we study something it’s synthesized and controlled and may not be what you have access to over the counter. And take a look at study dosages to get an idea of what’s being studied vs. whatever you see on the label. http://www.ncbi.nlm.nih.gov/pubmed?term=L-Theanine
In my non-medical opinion, it doesn’t look like it could _hurt_ and, who knows, it might help. (But of course only your doctor can say for sure.)
(I would say don’t sink a lot of cash into it, but likely, you won’t have to.)
- Natasha