In this blog post, I’ll just briefly discuss a topic that I’ve been seeing online quite a bit lately—the use of St. John’s Wort as a treatment for depression. Whenever a person asks about natural treatments for depression, it’s almost inevitable that someone will mention this herb. This herb has been used as a treatment for depression for years. But is it really an effective treatment for depression? And if it is an effective treatment, are there any risks to taking this herb? Let’s find out.

Medicinal Uses for St. John’s Wort

Hypericum perforatum, also known as St. John’s wort, has been studied for its ability to increase blood flow to the brain and enhance cognition; to treat depression; and to treat wounds, burns, and muscle aches. By far, the herb has been studied most frequently in an attempt to determine whether or not it is an effective treatment for depression.

Regarding its use for depression, the most up-to-date, large-scale, meta-analysis (as of September 2016) that looked at the benefits of Hypericum found that for mild to moderate depression, St. John’s Wort was as safe and as effective as serotonin-specific reuptake inhibitors (SSRIs), the drugs that are typically prescribed to treat depression. The conclusion of another study was that “Both St John’s wort extract and SSRIs are effective in treating mild-to-moderate depression. St John’s wort extract is safer than SSRIs.”

Through these studies, we find that St. John’s Wort is both a safe and effective treatment for mild to moderate depression, but are there any contraindications to the use of St. John’s Wort? Is St. John’s Wort safe and effective for all people who are suffering from mild to moderate depression?

St. John’s Wort: Cautions and Contraindications

Although St. John’s Wort has been shown to be both safe and effective, it really is not safe for everyone at all times and here’s why: the herb is metabolized through an enzyme in the body that also metabolizes a lot of other medications. Hypericum is what is known by the medical community as an inducer of the CYP3A4 enzyme in the cytochrome p450 system. What that means is that if you are taking another drug that is cleared from your body by that enzyme and you are also taking St. John’s Wort, the herb can cause your body to excrete the medication more quickly. This may sound kind of complicated, but you’re probably already familiar with the concept. If you’ve ever received a prescription and been told you couldn’t drink grapefruit juice with it, this is a similar concept. Instead of being an inducer, grapefruit juice is an inhibitor of the CYP3A4 enzyme, which means whereas St. John’s Wort causes your body to eliminate the drug more quickly, grapefruit juice keeps drugs that are cleared from the system through that enzyme in the body for a longer period of time.

For example, let’s say Shannon is taking oral contraceptive pills and they are cleared from the body through the CYP3A4 enzyme. Shannon decides to start taking St. John’s Wort as well to help with her depression. Because the herb is an inducer, taking this herb leads to her body clearing her birth control more quickly than usual. Her contraception is removed from her system more quickly than she needs it to be, so she doesn’t benefit from its effects the same way she did in the past. She becomes pregnant.

Drugs That are Cleared Through CYP3A4

Some drugs that are metabolized by the CYP3A4 enzyme and would be affected by St. John’s Wort include birth control pills, some antibiotics such as clarithromycin and erythromycin, benzodiazepines like alprazolam and diazepam, HIV antiviral drugs, some calcium channel blockers like verapamil and nifedipine, some statins, and quite a few other drugs.


In conclusion, St. John’s Wort can be as effective as SSRIs in treating mild to moderate depression. If you are taking medication and are considering taking St. John’s Wort, however, you should talk to your doctor and/or make sure the drugs you are taking are not metabolized by the CYP3A4 enzyme. This will help minimize side effects from taking the herb.

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