Can You Take St. John's Wort With Prozac?
In our latest question and answer, the pharmacist discusses whether or not St. John's Wort is safe to take with Prozac.
Hello, I'm looking for some advice. I take Prozac for depression and anxiety and have been wanting to take an herbal supplement to take along with it. I've read about St. John's Wort. Is that safe?
Jul 01, 2022- St. John's Wort and Prozac should not be used together because both increase serotonin in the brain, which can lead to a serious condition called serotonin syndrome with symptoms like high blood pressure, increased body temperature, and muscle twitching.
- If you need to switch from Prozac to St. John's Wort, you should wait at least 2 weeks after stopping Prozac, though waiting up to a month may be recommended to be safe.
Hello and thanks for reaching out! While it is often difficult to determine whether or not there are serious drug interactions between prescription drugs and herbal/nutritional supplements due to the lack of published information, St. John's Wort has been extensively studied. In fact, it is one of the most well-researched herbal medications in the world.
Since there is a large amount of published information regarding St. John's Wort, we have a fairly good idea about how it works, what it can be used for, and potential drug interactions to be concerned about.
As it concerns St. John's Wort and Prozac specifically, there is a significant interaction between them and they should not be used together in most cases.
Interaction Detail
The use of St. John's Wort and Prozac may result in an increased risk of serotonin syndrome (which is characterized by symptoms such as high blood pressure, increased body temperature, muscle twitching, and mental status changes).
This can occur since both St. John's Wort and Prozac increase the amount of the neurotransmitter serotonin in the brain.
Too much serotonin can result in serotonin syndrome, which is relatively rare, but a very serious condition if it does occur.
This interaction occurs not only between St. John's Wort and Prozac, but between St. John's Wort and all SSRIs (selective serotonin reuptake inhibitors), which include:
- Zoloft (sertraline)
- Luvox (fluvoxamine)
- Lexapro (escitalopram)
- Celexa (citalopram)
- Paxil (paroxetine)
How To Manage The Interaction
As mentioned, Prozac and St. John's wort should not be used together.
It is advised to wait two weeks after stopping St. John's Wort before restarting selective serotonin reuptake inhibitor therapy.
If you plan to replace a selective serotonin reuptake inhibitor (SSRI), like Prozac, with St. John's Wort, the half-life of the specific SSRI should be taken into consideration, waiting for at least 5 half-lives for the SSRI to be metabolized out of the body.
Prozac has an extremely long half-life, which is reported to be between 1 and 4 days. In some individuals, it can be as long as a week. For this reason, it takes a long time for our body to completely metabolize it. You should wait at least 2 weeks after stopping Prozac to start St. John's Wort. It may even be recommended to wait up to a month to be safe.
Final Words
Thanks again for your question and please feel free to reach out again in the future!
References & sources
Glossary — Terms in This Answer
- Drug interactions
- When two or more medications or supplements affect how each other works in your body.
- Herbal medications
- Medicines made from plants or plant extracts used to treat health conditions.
- Serotonin syndrome
- A serious condition caused by too much serotonin in the brain, which can cause high blood pressure, fever, muscle twitching, and changes in mental status.
- Neurotransmitter
- A chemical messenger in the brain that helps transmit signals between nerve cells.
- SSRIs
- A class of antidepressant medications that work by increasing serotonin levels in the brain.
- Selective serotonin reuptake inhibitors
- Antidepressant drugs that prevent the brain from reabsorbing serotonin, allowing more of it to remain active.
- Half-life
- The amount of time it takes for half of a drug dose to be eliminated from your body.
- Metabolized
- The process by which your body breaks down and eliminates a drug.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
More answers from Brian →