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Product Review

St. John's Wort Supplements Review

Find the Best St. John's Wort Supplement. Only 40% of St. John's Wort Supplements Pass Tests & Strength Varies Widely.

St John's Wort Supplements Reviewed By Consumerlab.com

CL Answer

Are there any supplements I should avoid when taking an antibiotic? Are there any that may be helpful?

Find out which supplements can negatively interact with antibiotics, including vitamin K, magnesium, and calcium, and which may be helpful when taking antibiotics.

Supplement Interactions With Antibiotics -- man reading prescription bottle instructions

CL Answer

What are the best supplements for depression and anxiety?

Best natural supplements for depression and anxiety, including the evidence for fish oil, vitamin D, probiotics, and herbal supplements for depression such as curcumin (from turmeric) and saffron.

Best Supplements for Depression and Anxiety -- sad young woman sitting on couch, looking toward the window

CL Answer

Supplements for Attention-Deficit/Hyperactivity Disorder (ADHD): Are Any Helpful?

Dietary supplements are often explored as alternative options or add-on interventions for people with ADHD. Learn which, if any, have shown possible benefit and which don’t seem to help or may interfere with ADHD medication.

Dice spelling adhd

CL Answer

Is it safe to take arginine, or other supplements for sexual enhancement, while taking Viagra or Cialis?

When taking Cialis or Viagra, is it safe to take arginine or other sexual enhancement supplements?

Man Holding Blister Packs of Supplements

CL Answer

I take fluoxetine (Prozac), a SSRI drug to treat depression. Are there supplements I should avoid, or be taking, due to this drug?

Learn about Prozac (fluoxetine) drug interactions along with other supplements and SSRIs.

Woman Taking Pill with Glass of Water

Clinical Update

10/10/2014

Caution with St. John's Wort

St. John's wort is known to interact with a large number of prescription drugs. That number grew larger recently when the FDA approved two new drugs to cure hepatitis C infection. Taking these drugs while using St. John's wort may lead to reduced therapeutic effect and is not recommended. More information about this and other drug interactions with St. John's wort is found in the "Concerns and Cautions" section of the St. John's Wort Supplements Review >>

Product Update

11/03/2025

St. John's Wort – 22 Products Fail

Twenty-two out of 23 St. John's wort supplements sold on Amazon fell short on a key St. John's wort compound -- 6 had none at all! See details in our St. John’s Wort Supplements Review, which includes our Top Pick for St. John's wort.

CL Answer

What supplements should I stop taking before surgery?

Info on which supplements to avoid before surgery due to increased risk of bleeding or interference with anesthesia.

Supplements to stop before surgery - operating room

CL Answer

I've heard that grapefruit juice can interact with medications because it inhibits an enzyme that breaks down drugs in the body. Do any supplements interact the same way with drugs?

CYP3A4 inhibitors, such as grapefruit, can interact with certain medications by inhibiting the liver enzyme that metabolizes many drugs. ConsumerLab.com's answer explains.

Grapefruit Juice, CYP3A4 and Supplement Interactions -- glass of grapefruit juice and grapefruit halves

CL Answer

Are there supplements, foods, or beverages that I should avoid when taking clopidogrel (Plavix)?

Learn about supplement interactions with clopidogrel (Plavix). Supplements that may interact with this medication include cannabidiol (CBD), grapefruit, St. John's wort, ginkgo and others.

Clinical Update

8/05/2015

Adverse Reactions with St. John's Wort

A recent analysis found adverse reactions associated with St. John's wort were similar to those reported for the prescription SSRI antidepressant fluoxetine (Prozac), and serious adverse reactions were most likely to occur when the herb was taken in addition to a prescription drug. Get the details, plus more about concerns and potential drug interactions and our tests of popular supplements in the St. John's wort Supplements Review >>

CL Answer

I take warfarin (Coumadin), an anticoagulant drug. Are there supplements I should avoid, or be taking, due to this drug?

Find out which supplements should be avoided when taking blood thinners (anticoagulants) like warfarin (Coumadin), including vitamin K, St. John's wort, and curcumin.

Warfarin Supplement Interactions -- bottle of pink warfarin tablets

CL Answer

I take lisinopril (Zestril), an ACE inhibitor drug to lower blood pressure. Are there supplements I should avoid, or be taking, due to this drug?

When taking ACE inhibitors, find out which supplements should be avoided. Interaction info on Lisinopril or another ACE inhibitors.

Lisinopril, ACE Inhibitors and Supplement Interactions -- prescription bottle of lisinopril on desk with blood pressure cuff

CL Answer

Which supplements can cause diarrhea?

Can supplements like magnesium cause diarrhea? Find out which supplements may cause diarrhea, such as vitamin B12, curcumin, magnesium, vitamin C and fish oil.

Which supplements can cause diarrhea? -- Woman with gastrointestinal pain

Clinical Update

6/21/2024

Unlisted Plants in Herbal Supplements?

A DNA analysis of herbal supplements in 2013 suggested that many contained plants not listed on labels. However, some of those findings seem to have been made-up, according to a recent investigation. For details, see the update in the St. John’s Supplements Review.

Clinical Update

7/08/2024

Herbal Supplement Study Retracted

A DNA study that suggested widespread problems with herbal supplements has been retracted. Get the details in our St. John’s Wort Supplements Review.

Clinical Update

10/13/2013

Most Herbal Products Don't Contain Listed Herb

DNA analysis of 44 herbal products from Canada and the U.S. found that only 48% contained the herb listed on the label and one-third of these products contained contaminants or fillers not listed on the label (Newmaster, BMC Med 2013). Nine percent of products contained only rice or wheat and none of the listed herb. Many cases of herb substitution were reported, including senna (a laxative) in a product labeled as St. John's wort. Several products were contaminated with feverfew, which should not be consumed by pregnant women and may react with a variety of medications. The researchers, from the University of Guelph in Ontario, did not disclose the identities of the tested products, which were single-ingredient herbs sold as capsules, powders, or tablets. Significant challenges continue to exist for routine use of DNA analysis of herbs, but ConsumerLab.com may use this technique where appropriate in the future, alongside other analytical techniques in its Product Reviews.   

News Release

September 26, 2016

60% of St. John's Wort Supplements Fail ConsumerLab.com Tests of Quality

White Plains, New York, September 26, 2016 — St. John's wort extracts can be as effective as standard antidepressant drugs for treating mild to moderate major depression, with significantly fewer side effects. However, recent ConsumerLab.com tests revealed that six of ten St.

News Release

April 14, 2010

ConsumerLab.com reports most St. John's wort supplements fail quality tests -- An effective antidepressant herb but heavy metal contamination and low potency are concerns

White Plains, New York — April 14, 2010 — St. John's wort has been shown to be effective in treating mild to moderate forms of major depression, but a new report from ConsumerLab.com shows that few of the herbal supplement brands recently tested met quality standards. Among the ten St.

News Release

February 14, 2007

ConsumerLab.com reports on anti-depressant herb — St. John's Wort — Few supplements pass quality testing

WHITE PLAINS, NEW YORK — FEBRUARY 14, 2007 — St. John's wort may be helpful in treating mild to moderate cases of clinical depression, but a new report from ConsumerLab.com shows that few of the herbal products tested met quality standards. Americans purchased $64 million of St.

News Release

April 27, 2004

New ConsumerLab.com report on St. John's wort highlights benefits and risks of herbal product for depression

NEW CONSUMERLAB.COM REPORT ON ST.

News Release

July 10, 2002

Pharmavite dietary supplements receive ConsumerLab.com approval — Vitamin E, SAM-e, St. John's Wort, Ginkgo and others merit approved quality products ranking

WHITE PLAINS, NY — July 10, 2002 — ConsumerLab.

News Release

April 10, 2001

Quality of popular herbal anti-depressant found to vary; certain types of St. John's Wort supplements more likely to pass testing

White Plains, NY — April 11, 2001 — ConsumerLab.com, an independent evaluator of dietary supplements and nutrition products, today released results of its Product Review of St. John's wort supplements.

Recalls & Warnings

June 12, 2025

NOW Nutritional Yeast Powder Recalled

On May 8, 2025, Now Foods recalled 18,658 units of NOW Nutritional Yeast Powder because regular yeast was inadvertently packaged as nutritional yeast.

Recalls & Warnings

February 22, 2021

FDA Warns Sellers of St. John's Wort

On February 18, 2021, the FDA issued warning letters to two companies following reviews of the companies' websites, which found statements made about the companies' St. John's Wort products to be drug claims. These products include St.

Recalls & Warnings

February 09, 2016

St. John's Wort Supplements Recalled

On February 8, 2016, the Medicines and Healthcare products Regulatory Agency (MHRA) (the British equivalent of the FDA) announced that certain St. John's wort supplements are being recalled because they contain excessive levels of a toxic pyrrolizidine alkaloid (PA).

Recalls & Warnings

May 03, 2013

Maker of Omega-3, Saw Palmetto, St. John’s Wort Supplements And More Warned For Manufacturing Violations and Drug Claims

On March 19, 2013, the FDA issued a warning letter to Sunset Natural Products Inc.

Recalls & Warnings

December 16, 2015

Maker of Red Yeast Rice, St. John's Wort, Valerian and More Warned for Manufacturing Violations, Drug Claims

On December 2, 2015, the FDA issued a warning letter to Nature's Health, LLC, following a facility inspection which found the company's product, including Ginkgo & Rhodiola, Blood Sugar Balance IV, Cinnamon Extract, Choles-Balance Red Yeast Extract, Lecithin, Milk Thistle Seed Extract, ...

Recalls & Warnings

April 17, 2015

Herbal Laxative and "Detox" Kit Containing High Levels of Lead and/or Arsenic Recalled in Canada

On April 15, 2015, Health Canada (the Canadian equivalent of the U.S. FDA) announced that St. Francis Herb Farm Inc.

Recalls & Warnings

July 13, 2012

Alistrol Health Inc. Warned Over Health Claims on Products

On June 26, 2012, the FDA issued a warning letter to Alistrol Health Inc. for making product statements on the company's websites that constitute drug claims.

Recalls & Warnings

September 16, 2015

Herbal Extracts Recalled

On September 15, 2015, Iowa Select Herbs, LLC issued a recall of numerous herbal exacts following a permanent injunction which required the company to stop selling supplements.

Recalls & Warnings

November 03, 2014

Mixing Medications and Dietary Supplements Can Be Dangerous, FDA Warns

On October 27, 2014, the FDA advised consumers to be aware of potential interactions between dietary supplements and over-the-counter (OTC) medications and/or prescription medications.

Recalls & Warnings

November 28, 2014

Seller of Herbal Extracts Warned for Manufacturing Violations, Drug Claims

On November 3, 2014, the FDA issued a warning letter to Avena Botanicals, Inc.

Recalls & Warnings

August 30, 2012

Supplement Company Warned For Medical Claims and Misbranding Of Omega-3, CoQ10, Noni Juice And More

On July 12, 2012, the FDA issued a warning letter to Alfa Vitamins Laboratories, Inc.

Recalls & Warnings

November 07, 2015

Seller of "NaturalDoctor" Vitamin C, Echinacea and More Warned for Manufacturing Violations

On October 16, 2015, the FDA issued a warning letter Sound Healing Arts, PC, dba Grounds for Tea, LLC, following a facility inspection which found the company's products, including  NaturalDoctor Vitamins C & K3, NaturalDoctor Goldenseal & Echinacea Plus, NaturalDoctor Centella ...

Recalls & Warnings

October 21, 2014

Seller of Weight Loss, Saw Palmetto Supplements and More Warned for Drug Claims

On October 9, 2014, the FDA issued a warning letter to Bethel Nutritional Consulting, Inc., following a review of the company's website which found statements made about 15 Day Detox Diet, Alpha Lipoic Acid. 300 mg.

Recalls & Warnings

August 26, 2014

Maker of Herbal Supplements Warned for Manufacturing Violations and Drug Claims

On August 8, 2014, the FDA issued a warning letter to EnerHealth Botanicals, LLC following a facility inspection which found the company's products, including Parasite Purge Herbal Remedy, Black Walnut Extract, Bladder Cleanse Herbal Extract, Lung Renewal Herbal Remedy, EchinOsha and Daily Immune ...

Recalls & Warnings

May 30, 2014

Seller of Brain, Diabetes, Echinacea Supplements and More Warned for Drug Claims

On April 22, 2014, the FDA issued a warning letter to Mundo Natural Inc., following a review of the company's website which found statements made about supplements Neuro AD, Stop Diabetes, Stop High Blood Pressure, Morninga 7 and Purpurea Echinacea to be drug claims.

Recalls & Warnings

January 17, 2017

Seller of Heart, Senior and Teen Supplements Warned For Drug Claims

On December 7, 2016, the FDA issued a warning letter to Esteem Products Ltd following a review of the company's website, which found statements made about its products, Cardio Life, Total Man, Total Woman, Senior Total Man, Senior Total Woman , and Total Teen to be drug ...

Recalls & Warnings

February 19, 2014

Seller of Sexual Enhancement Supplements Warned For Manufacturing Violations

On February 11, 2014, the FDA issued a warning letter to Maximus Niterider International Group, Inc.

Recalls & Warnings

December 16, 2013

Weight Loss Capsules Recalled Due Allergen Risk

On December 13, 2013, Stone Independent Research, Inc. issued recall of one lot of Zanocap Scientific Weight Loss 500 mg capsules because they contain undeclared whey protein, which is derived from milk.

Recalls & Warnings

January 30, 2013

Seller of Omega-3 and Emu Oil Supplements Warned For Drug Claims, Misbranding

On November 19, 2012, the FDA issued a warning letter to Emu Products & Management, Inc. after a review of the company's website found statements that promoted the dietary supplements Multi-Omega Gel Caps, Recovery Gel Caps, ARP Gel Caps and the topical skin products Extreme Cryo Gel, F.A.C.E.

Recalls & Warnings

December 26, 2012

Seller of Blood Sugar, Depression and Sleep Supplements Warned For Making Drug Claims

On October 15, 2012, the FDA issued a warning letter to BioNeurix Corporation after statements found on the company's website, http://www.pharma-tree.com, were found to promote the dietary supplements Blood Sugar 360, Amoryn, Seredyn, and Mellodyn as drugs.

Recalls & Warnings

February 03, 2015

Major Retailers Accused of Selling Adulterated Herbal Supplements

On February 3, 2015, the New York State Attorney General announced that his office sent letters to four major retailers, GNC, Target, Walmart, and Walgreens, for allegedly selling store brand herbal supplement products in New York that either could not be verified to contain the labeled substance, ...

Recalls & Warnings

June 20, 2003

Mixing Herbal Supplements, Migraine Medications Can Be Dangerous

On June 19, 2003, ABC News reported than an extensive review of existing research has led University of Utah researchers to conclude several popular herbal supplements may cause adverse, even deadly, reactions when combined with certain migraine medications.

Recalls & Warnings

May 14, 2014

Maker of Mood, Smoking Cessation Supplements and More Warned for Violations, Drug Claims

On April 17, 2014, the FDA issued a warning letter to CDJ Holding, Incorporated, d.b.a.

Recalls & Warnings

August 06, 2016

Some Supplements May Cause or Exacerbate Heart Failure (Includes vitamin E and many herbs)

Taking certain supplements may be dangerous for people with heart failure, according to a statement from the American Heart Association (AHA) which was published in the journal Circulation (August 2, 2016). 

Recalls & Warnings

September 07, 2002

FDA Sends Warning Letters to Seven Online Supplement Sellers For Therapeutic Claims

On August 27, 2002, the FDA posted seven "Cyber" letters recently issued from its Center for Food Safety and Applied Nutrition (CFSAN) to internet website operators promoting dietary supplement products that claim to diagnose, mitigate, treat, cure, or prevent a specific disease or class of ...

Recalls & Warnings

March 21, 2013

Probiotic Recalled Due To Undeclared Soy

On March 20, 2013, New Chapter, Inc. issued a voluntary recall of one lot of its Probiotic Elderberry dietary supplement because it may contain undeclared soy.