Bulbine Natalensis + Norelgestromin, Ethinyl Estradiol
Norelgestromin, Ethinyl Estradiol brand names: Ortho Evra, Evra.
Norelgestromin, Ethinyl Estradiol falls into 3 drug categories that Bulbine Natalensis can interact with; the most serious is rated moderate. Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP1A2 substrates.
Read the full interaction reportBulbine Natalensis and Norelgestromin, Ethinyl Estradiol
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Bulbine Natalensis interacts with whole categories of medication. Norelgestromin, Ethinyl Estradiol falls into 3 of those categories, so it can interact with Bulbine Natalensis in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES
1 of 3Why this applies to Norelgestromin, Ethinyl Estradiol
Norelgestromin, Ethinyl Estradiol falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Bulbine Natalensis interacts with.
In vitro research shows that Bulbine natalensis stem extract slightly induces CYP1A2 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP1A2 substrates; however, this has not been studied in humans.
Interaction 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.
If you're using the Ortho Evra patch (norelgestromin with ethinyl estradiol) for birth control, here's the gist. In lab dishes, Bulbine natalensis appears to slightly speed up an enzyme called CYP1A2, which helps break down the estrogen part of your patch. In theory, revving up that enzyme could clear the hormones a bit faster and lower their levels. With contraception, weaker hormone levels can mean breakthrough bleeding or, at worst, less reliable pregnancy protection.
That said, this is only test-tube data, not anything shown in real people, so the actual risk is uncertain. I'd still loop in your pharmacist or doctor before combining them, especially since this supplement also raises liver and kidney safety questions.
- Husain I, Manda V, Alhusban M, et al. Modulation of CYP3A4 and CYP2C9 activity by Bulbine natalensis and its constituents: An assessment of HDI risk of B. natalensis containing supplements. Phytomedicine 2021;81:153416. PubMed
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
2 of 3Norelgestromin, Ethinyl Estradiol also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
In vitro research shows that Bulbine natalensis stem extract induces CYP3A4 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP3A4 substrates, but this has not been studied in humans.
Interaction 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.
Here's the thing to know about the Ortho Evra (Evra) patch: the hormones in it, especially the estrogen, are partly broken down by a liver enzyme called CYP3A4. In lab studies, Bulbine natalensis seemed to speed up that enzyme. If that holds true in people, your body could clear the patch's hormones a little faster, which in theory might weaken how well it works. The real-world worry there is reduced birth control protection, and possibly breakthrough spotting or irregular bleeding.
I want to be honest though: this is only a test-tube finding, not something proven in humans, so we can't say how big the effect would be. Since pregnancy prevention is too important to gamble on, please check with your pharmacist or doctor before combining the two.
- Husain I, Dale OR, Manda V, et al. Bulbine natalensis (currently Bulbine latifolia) and select bulbine knipholones modulate the activity of AhR, CYP1A2, CYP2B6, and P-gp. Planta Med 2022;88(12):975-984. PubMed
P-GLYCOPROTEIN SUBSTRATES
3 of 3Norelgestromin, Ethinyl Estradiol also falls under P-GLYCOPROTEIN SUBSTRATES.
In vitro research shows that Bulbine natalensis stem extract induces p-glycoprotein mRNA expression; however, effects on transporter expression were not evaluated.
Interaction 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.
Here's the honest picture with your Ortho Evra (Evra) patch and Bulbine natalensis. The patch delivers a steady dose of estrogen and progestin to prevent pregnancy. The only signal we have is from lab dish (in vitro) research, where Bulbine seemed to increase the activity of a transporter protein called p-glycoprotein. If that happened in the body, it could move some hormone out faster and possibly lower the levels keeping you protected.
I want to be clear: this is theoretical and unproven in people, so I'm not alarmed. Still, since reduced birth control coverage can mean breakthrough bleeding or an unintended pregnancy, and because Bulbine has raised liver and kidney concerns in animals, please run it by your pharmacist or doctor before combining them.
- Husain I, Manda V, Alhusban M, et al. Modulation of CYP3A4 and CYP2C9 activity by Bulbine natalensis and its constituents: An assessment of HDI risk of B. natalensis containing supplements. Phytomedicine 2021;81:153416. PubMed
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
- ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
- 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.
- UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
- AHigh-quality meta-analysis (quantitative systematic review).
- BCase-control study.
- CConsensus.
- DAnecdotal evidence.
These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.
Bulbine Natalensis Also Interacts With Other Medications
Bulbine Natalensis has 919 moderate known drug interactions in our database — the Norelgestromin, Ethinyl Estradiol one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Bulbine Natalensis
We haven’t checked that one against Bulbine Natalensis yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Bulbine Natalensis. Pick one to open its full report.
See Every Supplement That Interacts With Norelgestromin, Ethinyl Estradiol
This page covers Bulbine Natalensis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Norelgestromin, Ethinyl Estradiol page lists 203 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate), Activated Charcoal (moderate) and Adrafinil (moderate).
By severity: 2 major · 168 moderate · 33 minor.
From our pharmacist’s overview on the Norelgestromin, Ethinyl Estradiol page
“St. John's wort is the first entry to check if you wear the Ortho Evra patch (norelgestromin and ethinyl estradiol).”
Reviewed by 2 · Jul 18, 2026
Taking Bulbine Natalensis as Part of a Dietary Supplement Product? Check It for Interactions
We hold 51 real supplement products containing Bulbine Natalensis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bulbine Natalensis. Your product may carry other ingredients that interact with Norelgestromin, Ethinyl Estradiol too, on top of Bulbine Natalensis — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Bulbine Natalensis and Norelgestromin, Ethinyl Estradiol Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#466 of 1,452 supplements looked up here in the last 7 days
#398 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
About Bulbine Natalensis
What is Bulbine Natalensis?
- Boosting testosterone
- Improving libido
- Muscle building and athletic performance
- General male vitality
Bulbine natalensis is a South African plant marketed mainly as a testosterone-boosting and libido supplement, but the human evidence is essentially absent and most claims come from animal studies. Animal research has also raised concerns about possible liver and kidney harm at higher doses, so caution is warranted. Talk to your pharmacist or doctor before trying it.
Other Drugs & Bulbine Natalensis
Browse every other medication we’ve checked against Bulbine Natalensis — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
919 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Theophylline ›
- Nifedipine ›
- Ibuprofen ›
- Aspirin ›
- Hydrocortisone ›
- Naproxen ›
- Doxycycline ›
- Erythromycin ›
- Estradiol ›
- Minocycline ›
- Propranolol ›
- Tetracycline ›
- Lidocaine ›
- Ranitidine ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Glyburide ›
- Methyltestosterone ›
- Triazolam ›
- Zopiclone ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Oxybutynin ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Triamcinolone ›
- Apomorphine ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Dipyridamole ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Indomethacin ›
- Miconazole ›
- Morphine Sulfate ›
- Trimipramine ›
- Acetaminophen ›
- Buprenorphine ›
- Conjugated Estrogens ›
- Diazepam ›
- Everolimus ›
- Ivabradine ›
- Ivermectin ›
- Ketoprofen ›
- Lofepramine ›
Showing 60 of 919 moderate interactions — see all 919 on the Bulbine Natalensis page.
No interaction 1,910 drugs checked — show the list
We also checked Bulbine Natalensis against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Rosuvastatin ›
- Metoprolol ›
- Isotretinoin ›
- Tirzepatide ›
- Levothyroxine, Liothyronine ›
- Docusate ›
- Methamphetamine ›
- Metformin ›
- Semaglutide ›
- Lisdexamfetamine ›
- Hydroxyurea ›
- Valacyclovir ›
- Amphetamine ›
- Sumatriptan ›
- Methotrexate ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Azithromycin ›
- Pregabalin ›
- Gabapentin ›
- Dextroamphetamine ›
- Lamotrigine ›
- Acyclovir ›
- Duloxetine ›
- Methylene Blue ›
- Ciprofloxacin ›
- Candesartan Cilexetil ›
- Amoxicillin, Clavulanate Potassium ›
- Insulin Degludec, Liraglutide ›
- Bisoprolol ›
- Calcium Oxybate, Magnesium Oxybate, Potassium Oxybate, Sodium Oxybate ›
- Amphetamine Aspartate, Amphetamine Sulfate, Dextroamphetamine Saccharate, Dextroamphetamine Sulfate ›
- Aminophylline, Amobarbital, Ephedrine ›
- Atenolol, Chlorthalidone ›
- Enalapril Maleate ›
- Bendroflumethiazide, Rauwolfia Serpentina ›
- Ephedrine, Phenobarbital, Theophylline ›
- Cephalexin ›
- Ezetimibe ›
- Bismuth Subcarbonate, Calcium Carbonate, Opium ›
- Isoniazid, Pyrazinamide, Rifampin ›
- Levetiracetam ›
- Levodopa ›
- Cyclopentolate ›
- Insulin Aspart, Insulin Degludec ›
- Canagliflozin, Metformin ›
- Hydrocortisone, Clioquinol, Pramoxine ›
- Daunorubicin, Cytarabine ›
- Candesartan Cilexetil, Hydrochlorothiazide ›
- Sodium Bicarbonate (otc Drug) ›
- Amobarbital, Ephedrine Sulfate ›
- Saxagliptin, Metformin Xr ›
- Efgartigimod Alfa-fcab ›
- Alginic Acid, Aluminum Hydroxide ›
- Measles, Mumps, Rubella Virus Live ›
- Carbidopa, Levodopa ›
- Ceftolozane Sulfate, Tazobactam Sodium ›
Showing the 60 most looked-up of 1,910 medications checked with no known interaction — see the full Bulbine Natalensis list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
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
Norelgestromin, Ethinyl Estradiol Is Linked to Lower Levels of 7 Nutrients
Natural Medicines records Norelgestromin, Ethinyl Estradiol as a medicine that can lower these. This is not an interaction with Bulbine Natalensis — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Norelgestromin, Ethinyl Estradiol nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Bulbine Natalensis and Norelgestromin, Ethinyl Estradiol Together: Common Questions
Can you take Bulbine Natalensis with Norelgestromin, Ethinyl Estradiol?
Why are there 3 interactions listed for Bulbine Natalensis and Norelgestromin, Ethinyl Estradiol?
How serious is the Bulbine Natalensis and Norelgestromin, Ethinyl Estradiol interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.