Bog Labrador Tea - Plan B (Levonorgestrel) Interaction
Herbal: Bog Labrador Tea
Also Known As: Rhododendron groenlandicum, Bog Tea, Continental Tea, Country Tea, Hudson's Bay Tea, Labrador tea, Lédon du Groenland, Muskeg Tea, Rusty Bog Labrador tea, Settler's Tea, St. James' Tea, Té de Labrador, Thé du Labrador, Thé Velouté, Tundra Tea
Drug: Levonorgestrel
Brand names:
Plan B, Mirena, Levonelle One Step, Levonelle 1500, Norgeston, Skyla, Liletta, Kyleena
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 18, 2025
Interaction Details
Levonorgestrel is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
In vitro research shows that aqueous and ethanolic extracts of Bog Labrador tea leaves can increase the concentration of cytochrome P450 3A4 (CYP3A4) enzymes. Extracts obtained from different geographical regions in Quebec resulted in differing potency of CYP3A4 induction. Bog Labrador tea might increase the metabolism of CYP3A4 substrates.
Drugs metabolized by CYP3A4 include lovastatin (Mevacor), clarithromycin (Biaxin), cyclosporine (Neoral, Sandimmune), diltiazem (Cardizem), estrogens, indinavir (Crixivan), amiodarone (Cordarone), ticagrelor (Brilinta), triazolam (Halcion), and others.
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
- Tam TW, Liu R, Saleem A, et al. The effect of Cree traditional medicinal teas on the activity of human cytochrome P450-mediated metabolism. J Ethnopharmacol. 2014;155(1):841-6.
Bog Labrador Tea Overview
Bog Labrador tea (Rhododendron tomentosum) is a perennial shrub that is native to wetlands and bogs in North America. It is a member of the heath family (Ericaceae) and is closely related to other species of Rhododendron, such as azaleas and mountain laurel. It has dark green, leathery leaves and produces small, white or pink flowers that bloom in clusters in the spring.
Bog Labrador tea has a long history of use in traditional medicine, and it is believed to have a number of potential health benefits. It is thought to have astringent, diuretic, and expectorant properties, and it is sometimes used to treat respiratory conditions, such as coughs and bronchitis, as well as digestive disorders, such as diarrhea and indigestion. It has also been used as a natural remedy for anxiety and stress.
Levonorgestrel Overview
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Levonorgestrel is used to prevent pregnancy after unprotected sexual intercourse (sex without any method of birth control or with a birth control method that failed or was not used properly [e.g., a condom that slipped or broke or birth control pills that were not taken as scheduled]). Levonorgestrel should not be used to prevent pregnancy on a regular basis. This medication is to be used as an emergency contraceptive or backup in case regular birth control fails or is used incorrectly. Levonorgestrel is in a class of medications called progestins. It works by preventing the release of an egg from the ovary or preventing fertilization of the egg by sperm (male reproductive cells). It also may work by changing the lining of the uterus (womb) to prevent development of a pregnancy. Levonorgestrel may prevent pregnancy, but it will not prevent the spread of human immunodeficiency virus (HIV, the virus that causes acquired immunodeficiency syndrome [AIDS]) and other sexually transmitted diseases.
Bog Labrador Tea - More Interactions
Bog Labrador Tea interacts with 622 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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