Catechu - Myfembree (Relugolix, Estradiol, Norethindrone Acetate) Interaction
Herbal: Catechu
Also Known As: Black catechu, Acacia catechu: Acacia à Cachou, Acacia Catechu Heartwood Extract, Black Catechu, Black Cutch, Cachou, Cachou de Pegu, Cachou Noir, Acacia Cashoo, Cashou, Catechu Nigrum, Catecu, Cutch, Cutchtree, Dark Catechu, Er Cha, Khadira, Khair, Kher, Khoyer
Drug: Relugolix, Estradiol, Norethindrone Acetate
Brand names:
Myfembree

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Relugolix, Estradiol, Norethindrone Acetate is classified as belonging to the following category: Cytochrome P450 1A2 (Cyp1A2) Substrates
Theoretically, black catechu may increase the levels and clinical effects of CYP1A2 substrates.
Animal research shows that black catechu can increase theophylline concentrations in the blood, possibly by inhibiting CYP1A2. Theophylline is a CYP1A2 substrate.
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
- Al-Mohizea AM, Raish M, Ahad A, et al. Pharmacokinetic interaction of Acacia catechu with CYP1A substrate theophylline in rabbits. J Tradit Chin Med 2015;35(5):588-93.
Catechu Overview

Catechu - More Interactions
Catechu interacts with 462 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.
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Drug descriptions are provided by MedlinePlus.