Green Tea - Imodium (Loperamide) Interaction
Herbal: Green Tea
Also Known As: Camellia sinensis, Green Sencha Tea, Green Tea Extract, GTP, GTPF, Japanese Sencha Green Tea, Japanese Tea, Kunecatechins, Poly E, Polyphenon E, PTV, Té Verde, Tea Extract, Tea Green, Tea, Thé, Thé Vert, Yabukita, Yame Green Tea, Yame Tea
Drug: Loperamide
Brand names:
Imodium, Loperamide
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jun 15, 2025
Interaction Details
Loperamide is classified as belonging to the following category: P-Glycoprotein Substrates
Green tea might increase the levels and adverse effects of P-glycoprotein (P-gp) substrates.
In vitro research and case reports suggest that green tea inhibits drug efflux by P-gp, potentially increasing serum levels of P-gp substrates. Case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking green tea and certain P-gp substrates.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178.
Green Tea Overview
Green tea is a type of tea that is made from the leaves of the Camellia sinensis plant. It is native to Asia and is widely consumed throughout the world. Green tea has a mild, slightly grassy flavor and is typically lighter in color and less astringent than black tea.
Green tea is a rich source of antioxidants, particularly a group of compounds called catechins. These antioxidants are thought to help protect cells from damage caused by free radicals. Green tea is also a good source of other nutrients, including vitamin C and several B vitamins.
Green tea is often consumed for a number of purported health benefits including reducing the risk of heart disease, immune-stimulating effects, and weight loss.
Oral green tea supplements, containing dried powder, are most often utilized for the caffeine content and used as an appetite suppressant for weight loss.
Loperamide Overview
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Nonprescription (over-the-counter) loperamide is used to control acute diarrhea (loose stools that come on suddenly and usually lasts less than 2 weeks), including travelers' diarrhea. Prescription loperamide is also used to control acute diarrhea and also ongoing diarrhea associated with inflammatory bowel disease (IBD; condition in which the lining of all or part of the intestine is swollen, irritated, or has sores). Prescription loperamide is also used to reduce the amount of fluid in people with ileostomies (surgery to create an opening for waste to leave the body through the abdomen). Loperamide is in a class of medications called antidiarrheal agents. It works by decreasing the flow of fluids and electrolytes into the bowel and by slowing down the movement of the bowel to decrease the number of bowel movements.
Green Tea - More Interactions
Green Tea interacts with 1251 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
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In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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