Supplements and antidepressants: St. John's wort, tryptophan and SSRIs

October 20, 2026By VitOptics Staff

Short answer: The prescribing information for sertraline (Zoloft), escitalopram (Lexapro) and duloxetine (Cymbalta) names St. John's wort and tryptophan among the products that raise the risk of serotonin syndrome, which the Zoloft label calls a potentially life-threatening condition. MedlinePlus asks you to tell your doctor and pharmacist if you take either one, and not to start them while on these medicines without discussing it with your healthcare provider. If you are thinking about any supplement, bring the label to your prescriber or pharmacist first.

This guide explains which products the labels name, where they can turn up, and the questions worth bringing to your next appointment. It does not replace your Medication Guide or your prescriber's instructions, and nothing here is a reason to change how you take your medicine.

SSRI, SNRI or another class: check yours

Antidepressants come in several classes, and each medicine has its own label. MedlinePlus describes sertraline and escitalopram as selective serotonin reuptake inhibitors (SSRIs), and duloxetine as a selective serotonin and norepinephrine reuptake inhibitor (SNRI). Duloxetine is also prescribed for some kinds of nerve and muscle pain, so you may be taking it for a reason that has nothing to do with mood.

Each MedlinePlus page lists the nonprescription or herbal products that may interact with that medicine. The lists overlap, but they are not identical:

Medicine	Class	Nonprescription or herbal products MedlinePlus lists
Sertraline (Zoloft)	SSRI	St. John's wort; tryptophan; aspirin and NSAIDs such as ibuprofen and naproxen
Escitalopram (Lexapro)	SSRI	Aspirin, ibuprofen (Advil, Motrin IB), naproxen (Aleve), St. John's wort, tryptophan
Duloxetine (Cymbalta, Drizalma Sprinkle)	SNRI	St. John's wort; tryptophan; proton pump inhibitors such as lansoprazole, omeprazole, pantoprazole and rabeprazole; cimetidine; aspirin and other NSAIDs such as ibuprofen and naproxen

If your medicine is not in this table, read its own Medication Guide or MedlinePlus page, or ask your pharmacist for the list that applies to you. Other antidepressants have their own labels, and their lists can differ.

St. John's wort

According to the National Center for Complementary and Integrative Health (NCCIH), St. John's wort is a plant with yellow flowers, and it is most widely promoted for symptoms of depression. The labels for all three medicines above name it. Section 5.2 of the Zoloft prescribing information says SSRIs and SNRIs "can precipitate serotonin syndrome, a potentially life-threatening condition," and that the risk is increased when they are used with other serotonergic products, a list that includes tryptophan and St. John's Wort. The Lexapro and Cymbalta labels carry the same warning.

NCCIH makes two related points. First, taking St. John's wort with certain antidepressants or other drugs that affect serotonin may lead to increased serotonin-related side effects, which can be serious. Second, St. John's wort can weaken the effects of many other medicines, and NCCIH lists birth control pills, warfarin, certain statins and some heart, seizure, HIV and cancer medicines among them. St. John's wort also appears on blood-thinner lists, and on the interaction lists for phenytoin and isotretinoin, which is one more reason to mention it at every medication review.

On a label, look for "St. John's wort," "hypericum" or the Latin name Hypericum perforatum. NCCIH notes it is also promoted for menopause symptoms, so it can sit inside a product you might not connect with mood. Read the full ingredient list, not just the product name.

Tryptophan and similar "mood" products

Tryptophan is the second supplement every one of these labels names. The Cymbalta Medication Guide groups the two together as "over-the-counter supplements such as tryptophan or St. John's Wort."

Blends can combine several ingredients, so the product name may not tell you what is inside. If you see a related ingredient that is not on your medicine's list, such as 5-HTP, ask your pharmacist whether it belongs on the same list for you. The sources linked in this article do not name 5-HTP, so treat it as a question rather than an answer either way.

Other over-the-counter products on these lists

The lists are not only about supplements. Aspirin and NSAIDs such as ibuprofen and naproxen appear on all three MedlinePlus pages. The Zoloft label explains why: drugs that interfere with serotonin reuptake increase the risk of bleeding events, and using aspirin, NSAIDs or blood thinners at the same time may add to that risk.

For duloxetine, MedlinePlus also lists proton pump inhibitors such as omeprazole, and cimetidine. MedlinePlus groups them with the nonprescription products, so include occasional use when you list what you take.

Signs the labels say need prompt attention

MedlinePlus asks you to "call your doctor immediately" if certain symptoms appear. The Lexapro Medication Guide puts it this way: "Call your healthcare provider or go to the nearest hospital emergency room right away if you or your child have any of the following signs and symptoms of serotonin syndrome:"

agitation
seeing or hearing things that are not real (hallucinations)
confusion
coma
fast heartbeat
blood pressure changes
sweating
shaking (tremors), stiff muscles, or muscle twitching
flushing
dizziness
seizures
high body temperature (hyperthermia)
nausea, vomiting, diarrhea
loss of coordination

Your own Medication Guide has the list for your medicine. Keep it somewhere you can find it, and make sure someone close to you knows where it is.

The same Medication Guide opens with a different warning. It says Lexapro and other antidepressant medicines increase the risk of suicidal thoughts and actions in people 24 and younger, especially in the first few months of treatment or when the dose is changed, and it asks you to watch for sudden changes in mood, behavior, thoughts or feelings. If you or someone you know is thinking about suicide, call or text 988 to reach the 988 Suicide & Crisis Lifeline, open 24 hours a day, or call 911 in an emergency.

What to ask your prescriber or pharmacist

Bring a list of every prescription medicine, nonprescription medicine and supplement you take or are thinking about, with photos of the Supplement Facts panels. Our guide to what to review before starting a new supplement can help you put it together. If you already take St. John's wort, tryptophan or a blend you are unsure about, say so plainly; MedlinePlus asks you to let your doctor and pharmacist know. Then ask:

Is my medicine an SSRI, an SNRI or something else, and which products does its label list?
Does anything I take contain St. John's wort, hypericum or tryptophan, under any name?
Do products like 5-HTP belong on the same list for my medicine?
How do aspirin, ibuprofen or naproxen fit with my medicine, including occasional use?
If I take duloxetine, how do omeprazole, cimetidine or similar medicines fit in?
Which symptoms should make me call you, and when should I go to an emergency room instead?
Who should I contact if I have questions between appointments?

Write down what you agree on and keep it with your Medication Guide. If no change is needed, record that too.

Where VitOptics fits

VitOptics builds a personalized daily supplement pack from a free, three-minute assessment. The free assessment asks which prescription medicines you take, along with the supplements you already use. Automated checks review the recommendation; some profiles need additional review by a person on our team. A second automated check reads the whole pack before release. Your result lists every formula, the amount of each ingredient and the reason it is there, so you can read it line by line. Our article on what a quiz can and can't tell you explains the limits of any online assessment, and this page explains how personalized vitamin packs work.

If you take an antidepressant, show your prescriber or pharmacist the full list of formulas and ingredients before you start a pack, the same way you would with any new supplement. Their answer comes first.

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Sources

Read more in the VitOptics learning hub.

This article is for educational purposes and is not medical advice. Supplements are not intended to diagnose, treat, cure or prevent any disease.

Prepared with AI assistance using the sources linked in this article.

Last updated: October 23, 2026

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