Everything You Should Know Before Trying St. John's Wort for Depression

Dubbed “nature’s antidepressant,” the herb St. John’s wort is a popular alternative to antidepressants for people with mild to moderate depression. Herbalists say this ancient herb also has other important uses—involving pain, wound healing, and more—that too often fly under the radar. With large numbers of adulterated herbs on the market, though, you may not always get what you’re expecting. Here’s everything you need to know if you’re considering taking the supplement:

The term wort means a plant used as a food or medicine. St. John’s Wort (SJW) is an herb that grows naturally around the world. Herbalists have long used the stems, leaves, buds, and fruit as a natural remedy. Other names for this herb are Hypericum perforatum (which is its official name), goatweed, Klamath weed, racecourse weed, and tipton weed. You can find St. John’s wort in health-food stores and pharmacies in the form of tinctures, fluid extracts, powders, oil infusions, or teas.

Although SJW has long been part of European folk medicine, according to the American Botanical Council (ABC), it was relatively obscure until the late 1990s, when the first European studies documented its effectiveness for treating mild to moderate depression. SJW is now big business, with the ABC noting that US sales reached $57 million in 2015.

When researchers at the Rand Corporation, a nonprofit global policy think tank, looked at 35 studies using the herb for mild-to-moderate depression they found that, for their participants, SJW was just as effective as taking an antidepressant. Their review, published in the journal Systematic Reviews in 2016, also revealed that in studies pitting SJW against a placebo, SJW came out ahead. Even better, side effects were significantly lower for people on SJW than a medication. They had fewer GI or neurological problems, and lower rates of sexual concerns.

“St. John's wort is valuable in the treatment of mild to moderate outpatient depression,” says Richard P. Brown, associate professor of clinical psychiatry at Columbia University in New York, who notes it is the most frequently prescribed “antidepressant” in Germany.

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Still, the number of patients examined in the aforementioned studies was relatively small, says the review’s coauthor Eric Apaydin, a policy researcher at Rand, in Santa Monica, Calif. What’s more, Apaydin says, “since it’s not a drug, the dosage and strain is not the same across all these studies, so it’s hard to know what the true effect is. There still needs to be more research.”

Not enough quality studies have examined SJW for major depression for experts to suggest using it for this condition. “We don’t know if it’s beneficial for severe depression or if it isn’t, but it’s not recommended for that because we don’t have the evidence,” Apaydin says. In any event, if you have severe depression, you should see a psychiatrist and not rely on an over-the-counter herb.

According to the ABC, lotions and oils containing SJW can be spread on the skin to treat bug bites, sunburns, wounds, and even hemorrhoids. Oils or tinctures taken internally help some people with inflammatory bowel problems. Tiny pilot studies or case reports have also shown SJW might be effective for premenstrual dysphoric disorder (PMDD), psoriasis, and atopic dermatitis.

It can also quell painful nerve pain for many. When Melanie St. Ours, 35, developed a stabbing pain in her tooth three years ago, her dentist suggested bonding the area to protect the nerve. As an herbalist in suburban Baltimore, Maryland, and the author of The Simple Guide to Natural Health, St. Ours knew that SJW is in a category of herbs called “nervines,” which are believed to impact the nervous system. She stopped by a store after leaving the dentist and picked up a tincture for $12.

For her, it was even more effective than she expected. As soon as she got home, she mixed a quarter-teaspoon of the tincture with a few ounces of water, swishing the mixture around her mouth before swallowing. Within ten minutes, she could feel the pain lessening. By the end of the week after regularly taking the product, all the pain had subsided. She has not gone back to the dentist for the bonding. Keep in mind that clinical trials have not verified this effect of SJW, although there are a few animal studies that suggest it, so a placebo effect could be at least partially at play.

You’ll want a product that is “standardized” (meaning it has a certain amount of the most active ingredient), since this is what the researchers use.

According to the Department of Veterans Affairs, which commissioned the Rand study in advance of updating its practice guidelines, people with mild depression who want to try the herb should look for an extract standardized to 0.3 percent hypericin. A good starting dose, the VA says, is 300 mg three times daily, increasing if there are no problematic side effects up to 1200 mg a day.

Probably the biggest side effect of SJW is that it can interact with many common medications. For this reason, the Mayo Clinic warns that it should not be taken by anyone on birth control pills (it can decrease their effectiveness). Mayo also cautions people on blood-thinning drugs, chemotherapy, HIV/AIDS medications, and medicine to prevent organ rejection after a transplant that problematic interactions can occur.

You should also not take SJW if you are on an antidepressant. The combination can cause serious complications, including a life-threatening condition known as serotonin syndrome. There are a few cases of people experiencing anxiety from taking the herb.

These cautions, along with side-effects like sun-provoked rashes, are the main reason some psychiatrists are wary. “Of any herb I could prescribe, St John's Wort is the one with the most herb-drug interactions,” says Lila Massoumi, clinical associate professor of psychiatry at Michigan State University and the chair of the American Psychiatric Association Caucus on Complementary & Integrative Psychiatry, who says she does not generally recommend SJW to her patients.

The problem with doctored or incorrectly labeled SJW has become serious, the ABC says. Before the drug became so popular, it was gathered from the wild. Once demand outpaced this supply, commercial farms in Asia and other countries began to cultivate it. Over the years, some of these imported herbs have come under question. It’s thought that some are simply mislabeled. But other SJW products have been found to have food coloring and other unwanted additives designed to confuse laboratory tests. What these products actually are is anyone’s guess.

Added coloring is especially problematic, because herbalists like St. Ours use the look of a tincture as one way to evaluate SJW’s potency. The best herbs are picked when the flowers peak in summer, St. Ours says. “If it is a deep ruby color, that tells you the plant was picked at the right time and processed in the right way.” With color-spiked products on the market, this may not always be true.

If you have tried SJW in the past and didn’t find it effective, you may want to buy from another, more reputable, company before deciding the herb does not work for you. “It is crucial to select a high quality brand, such as those that have been tested in scientific studies,” Brown advises.

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