Phellodendron - Premarin (Conjugated Estrogens) Interaction
Herbal: Phellodendron
Also Known As: Phellodendron amurense, Amur Cork Bark, Amur Cork Tree, Amur Corktree, Corktree, Cortex Phellodendri, Huang Bai, Huang Bo, Huangbai, Phellodendri Cortex
Drug: Conjugated Estrogens
Brand names:
Premarin, Cenestin, Enjuvia, Premarin Vaginal Cream
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 11, 2025
Interaction Details
Conjugated Estrogens is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.
Phellodendron contains berberine. In vitro research and preliminary clinical research show that berberine moderately inhibits CYP3A4. Theoretically, phellodendron might also inhibit CYP3A4.
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
- Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72.
- Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82.
- Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217.
- Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477.
Phellodendron Overview
Phellodendron amurense, also known as Amur cork tree, is a deciduous tree native to China, Korea, and Japan. It belongs to the Rutaceae family and is valued for its medicinal properties. The bark of Phellodendron amurense is used in traditional Chinese medicine for its purported anti-inflammatory, antimicrobial, and antioxidant effects. It contains compounds such as berberine, which is believed to contribute to its therapeutic properties. Phellodendron amurense has been studied for its potential to manage conditions like diabetes, inflammation, and cancer.
Conjugated Estrogens Overview
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The estradiol cypionate and estradiol valerate forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) and/or vaginal dryness, itching, and burning in women who are experiencing menopause (change of life; the end of monthly menstrual periods). However, women who need a medication only to treat vaginal dryness, itching, or burning should consider a different treatment. These forms of estrogen injection are also sometimes used to treat the symptoms of low estrogen in young women who do not produce enough estrogen naturally. The estradiol valerate form of estrogen injection is also sometimes used to relieve the symptoms of certain types of prostate (a male reproductive organ) cancer. The conjugated estrogens form of estrogen injection is used to treat abnormal vaginal bleeding that a doctor has decided is caused only by a problem with the amounts of certain hormones in the body. Estrogen injection is in a class of medications called hormones. It works by replacing estrogen that is normally produced by the body.
Phellodendron - More Interactions
Phellodendron interacts with 1134 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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