St John’s Wort is probably one of the most researched and self-prescribed herbs around, so I thought I’d let people know some info for safe usage. These are some of the things I have to think about, as a professional, before prescribing:
Pregnancy and breastfeeding: while this herb appears to be safe so far given studies on both pregnancy and breastfeeding, I tend to err on the side of caution in pregnancy and use less or no herbs (or only miscarriage-prevention herbs), especially if there is any history of miscarriage.
There is a wonderful word we use in herbal medicine called ‘contraindicated’, which is the opposite to ‘indicated’. When someone says “St John’s Wort is indicated in ___”, this means “use this herb for this condition”. If a herb is contraindicated for a particular condition, it means DONT use it.
For example, St Johns Wort is contraindicated for people who have skin photosensitivity, and people taking high doses should be careful if they get a lot of sun exposure or artificial UVA irradiation.
St Johns Wort has been listed as contraindicated with the following drugs: warfarin, digoxin, cyclosporin, indinavir and related anti-HIV drugs, the contraceptive pill… and many others! This is because doctors are worried that something in SJWort may make the body metabolise prescribed drugs faster and thus reduce their effectiveness. It looks like the cause for this might be a specific phytochemical called hyperforin that is present in some subspecies of STWort and not others. Low SJW doses of no more than 2g per day, and/or a form containing less hyperforin (e.g. liquid herbal extract like the ones us herbalists use!) can make SJW safe to use with prescribed drugs, but it should still be done with professional supervision. I’ve certainly seen people get pregnant while on the pill due to taking SJW concurrently (at the same time). So basically, if you are on prescribed medication, don’t self-prescribe SJW- get professional guidance. Continue reading