9 Things to Know Before Taking St. John’s Wort for Depression

St. John’s wort is a plant with vibrant yellow flowers that’s been used as an herbal medication for centuries. People take it as a natural treatment for depression and menopause symptoms, among other uses. But what does the science say about St. John’s wort? And what else should you know before you start taking it? Here are nine things to know before taking St. John’s wort.

1. St. John’s wort isn’t FDA-approved for depression

In the U.S., St. John’s wort is an over-the-counter (OTC) dietary supplement — not a prescription medication. That means there’s no FDA-approved use for it. And it’s not legal for companies that sell it to claim that it treats, prevents, or cures any health conditions.

That being said, there’s some mixed evidence that suggests St. John’s wort may be effective for the short-term treatment of mild to moderate depression. And it also seems to have fewer side effects than common prescription antidepressants. But most of the clinical trials showing that St. John’s wort has a positive effect on depression were small studies from Germany, where the available products are different from those in the U.S. Studies from the U.S. haven’t shown the same benefit. So it’s not entirely clear how effective St. John’s wort supplements are for depression symptoms.

2. Herbal supplements like St. John’s wort aren’t well regulated

Herbal supplements are less regulated than prescription medications. Supplements don’t have to be proven safe and effective before they’re sold. Low-quality herbal supplements may not actually contain the ingredients listed on the label, may have other unlisted ingredients, or may even be contaminated with heavy metals, bacteria, or pesticides.

Some tips to help choose a good supplement brand include:

• Look for third-party certifications from groups like the United States Pharmacopeia (USP).

• Use caution when buying supplements online.

• Avoid supplements that claim to cure a disease or seem “too good to be true.”

• Ask your pharmacist or healthcare provider to recommend a brand or product.

• Read the label carefully.

3. There isn’t a standard dose of St. John’s wort for depression

Since St. John’s wort isn’t FDA-approved, there isn’t a standard dose to take for depression. In clinical studies, the effective dosages were typically between 500 mg and 1,200 mg per day.

Taking 300 mg three times a day with meals may be a good place to start. And look for a capsule that contains 0.3% hypericin (the main active ingredient in St. John’s wort).

It’s best to speak with your healthcare provider about taking St. John’s wort. They can help recommend a dosage for you. It’s also a good idea to follow the recommended dosing instructions on the supplement bottle.

4. It may take several weeks for St. John’s wort to start working

If you do start using St. John’s wort, you shouldn’t expect immediate effects. Like many prescription antidepressants, it can take several weeks to start working. Most studies looked at people who had taken St. John’s wort for at least 4 weeks.

If you’re not seeing an improvement in your symptoms after several weeks, or if your depression symptoms worsen, check in with your healthcare provider. You may need a different treatment for your depression.

5. It can be dangerous to take St. John’s wort with other antidepressants

St. John’s wort can raise serotonin levels in the brain. Other antidepressant medications can raise serotonin levels, too. If they’re combined with St. John’s wort, a condition called serotonin syndrome is more likely to happen. This can be dangerous and even life-threatening if not treated.

Symptoms of serotonin syndrome include:

• Sweating

• Tremors

• High blood pressure

• Fast heart rate

• Agitation

• Diarrhea

• Confusion

If you’re taking any other medications for your depression symptoms, St. John’s wort may not be safe for you. Talk to your healthcare provider about the risks and benefits of adding it to your treatment regimen. If you notice any signs of serotonin syndrome while taking St. John’s wort, seek medical care right away.

6. St. John’s wort can make birth control pills less effective

St. John’s wort can speed the clearing of some medications from the body, including birth control pills. This could make your birth control pills less effective while you’re taking St. John’s wort — even if you’re taking them exactly how you’re supposed to. It could also cause irregular menstrual cycles or breakthrough bleeding. While most studies focus on oral birth control pills, it’s also possible St. John’s wort could affect other forms of hormonal birth control, such as patches or vaginal rings.

A backup birth control method may be a good idea if you’re trying to avoid becoming pregnant. If this interaction becomes bothersome, a different depression treatment may be a better option for you.

7. St. John’s wort can also interact with several other medications

Even though St. John’s wort is an OTC supplement, it has several medication interactions to be aware of. We’ve already discussed antidepressants, but there are several other medications that can also raise serotonin levels. If they’re combined with St. John’s wort, serotonin syndrome can happen. They include:

• Anti-nausea medications such as ondansetron (Zofran)

• Pain medications such as tramadol

• Dextromethorphan, an OTC cough suppressant

• Chlorpheniramine, an OTC antihistamine

• L-tryptophan, an OTC supplement

• Ginseng, an OTC supplement

St John’s wort can also make certain medications less effective by lowering their levels in the body. These include:

• Migraine medications such as sumatriptan (Imitrex) and ubrogepant (Ubrelvy)

• Benzodiazepines such as alprazolam (Xanax)

• Warfarin

• Digoxin

• Seizure medications such as carbamazepine (Tegretol) and phenytoin (Dilantin)

• HIV medications such as ritonavir (Norvir) and efavirenz (Sustiva)

• Transplant medications such as cyclosporine (Sandimmune) and tacrolimus (Prograf)

There are a large number of possible interactions with St. John’s wort. So be sure to give your healthcare provider an updated medication list to review before you start taking it. They can make sure there aren’t any possible interactions with other medications and supplements you take.

8. St. John’s wort has side effects to be aware of

St John’s wort seems to cause fewer side effects than prescription antidepressants. But it can still cause some issues. Common St. John’s wort side effects include:

• Minor skin irritation

• Nausea

• Headache

• Increased sun sensitivity (more likely at higher doses)

These issues are usually mild and may go away with time. If they’re bothersome, talk to your provider about OTC treatment options or lifestyle changes that may help. A lower dose of St. John’s wort may also help lessen side effects.

Good to know: You may experience withdrawal symptoms if you suddenly stop taking St. John’s wort. These symptoms seem to be less likely with St. John’s wort than if you stop taking prescription antidepressants, but they’re still possible. Your healthcare provider can help you stop taking St. John’s wort safely to avoid these effects.

9. St. John’s wort isn’t a replacement for professional mental health care

Even though there’s growing interest in taking herbal supplements like St. John’s wort for depression, OTC treatments aren’t a replacement for professional care. Untreated or undertreated depression can be harmful, and it can be hard to treat safely on your own.

If you’re feeling depressed or looking for a way to lift your mood, the best first step is to talk to a healthcare provider. They can figure out what’s causing your symptoms and help you decide on the best course of care.

Why trust our experts?

Written by:

Jill Barat, PharmD

Jill Barat, PharmD has nearly 10 years of experience as a pharmacist, including serving as the pharmacist in charge at an independent sterile and non-sterile compounding pharmacy. She also worked as the head of medical content for a telemedicine company.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Our editorial standards

Meet our experts