The Sunshine Flower

My reputation precedes me – Taylor Swift – St John’s Wort

Musical Lyrics and Office references aside, St John’s Wort (Hypericum perforatum) is a flower that has received a bad rep in the last few decades despite being used traditionally for centuries, so what gives?

I suppose before we delve into why St John’s Wort (SJW) has been criticized, I should share a little more about this fancy yellow flower for those who are not familiar. SJW has traditionally been used as a topical treatment for bruises, wounds, and skin irritation like bug bites. It has also been used to help melancholy due to the timing of its bloom. The flowers appear generally mid-June, coinciding with the summer solstice or St John’s day (see where the name comes from?). The superstition around the plant’s properties also meant that it would be placed in the home to ward off evil or be used as a charm around the neck to ward against witchcraft – history is cool isn’t it?

SJW can be found in many different soil types and produces warm yellow 5-petaled flowers. These hearty plants were introduced into North America from Europe and can be found in dedicated botanical or flower gardens but also in the wild.

Like many botanicals it is hard to pinpoint the exact phytochemicals that play a role in its medicinal effects but, hyperforin and hypericin have been researched as active constituents for SJW. Both hyperforin and hypericin interact directly with our central nervous system aka our brain. This direct interaction has been traditionally used to aid in improving mood as its mechanism of action can potentially help with dopamine and serotonin levels; both chemicals in the brain that help us feel happier! These traditional effects have played a role in the flower receiving the nickname of the sunshine flower by some.

Okay, now to the juicy bit!

SJW has effects in the liver as well. This interaction is what has given SJW a reputation of needing to use extreme caution when prescribing (and also that increased doses may case photosensitivity in some people). SJW can increase the rate at which some enzymes in our liver do their work; namely within the p450 system that helps to break down and clear out many different drugs from our system. This means that if you are prescribed a medication by your doctor, that SJW could have the potential to speed up the rate at which the liver gets rid of that drug from your system. This is not ideal with some medications as the dose you are prescribed is meant to last until the next time you take a pill – which may not be the case if the rate is increased too much. THIS is one reason why SJW has got a bad reputation as a reputable herbal remedy.

NOW, I’m not saying to ignore what I just told you about a potential risk of SJW, BUT what I am saying is that there appears to be more the story. Newer research and clinical case studies are suggesting that the amount of hyperforin is what needs to examined in relation to inducing drug metabolism. One study compiled data that looked at the amount of hyperforin per dose of SJW to see if there were interactions. They concluded that with low dose hyperforin (< 3mg daily) that there is little to no interaction with other drugs. This research then suggest that supplements containing low dose SJW and therefore low dose hyperforin, should be relatively safe to consume with other medications like antidepressants. This research revelation is not alone as there are several case studies and observational data showing patients taking SJW concurrently with other medications. This research should clear SJW reputation, right? Unfortunately, there is still not enough research to be 100% certain that no interaction will occur, especially given the individual nature of everyone’s metabolism and health status. BUT, that’s part of naturopathic medicine, what works for one may not work for all because we focus on individual care!

Okay, so you’ve hopefully learned more about SJW and why despite a strong traditional use for the botanical, there remains some hesitancy in prescribing the herb.

That being said the Canadian Network for Mood and Anxiety Treatments (CANMAT) listed St John’s wort as a 1st or 2nd line intervention for treating mild to moderate depression. There are other studies that list SJW as a suitable treatment for mild to moderate depression but they remain skeptical of the possible interactions I listed above.

As always, do your research and consult a health care professional before starting any new herbal supplement – especially SJW given what I talked about in this post!

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Pubmed Articles to check out on this topic:

Chrubasik-Hausmann S, Vlachojannis J, McLachlan AJ. Understanding drug interactions with St John's wort (Hypericum perforatum L.): impact of hyperforin content. J Pharm Pharmacol. 2019;71(1):129-138. doi:10.1111/jphp.12858

Nicolussi S, Drewe J, Butterweck V, Meyer Zu Schwabedissen HE. Clinical relevance of St. John's wort drug interactions revisited. Br J Pharmacol. 2020;177(6):1212-1226. doi:10.1111/bph.14936

Ravindran AV, Balneaves LG, Faulkner G, et al. Canadian Network for Mood and Anxiety Treatments (CANMAT) 2016 Clinical Guidelines for the Management of Adults with Major Depressive Disorder: Section 5. Complementary and Alternative Medicine Treatments. Can J Psychiatry. 2016;61(9):576-587. doi:10.1177/0706743716660290