Drug & supplement interaction

Neem + Ethinyl Estradiol, Norethindrone, Ferrous Fumarate

Ethinyl Estradiol, Norethindrone, Ferrous Fumarate brand names: Estrostep Fe, Loestrin Fe, Microgestin FE, Junel Fe 1.5/30, Loestrin Fe 1.5/30, and others.

Moderate Interaction
The bottom line Moderate

Ethinyl Estradiol, Norethindrone, Ferrous Fumarate falls into 3 drug categories that Neem can interact with; the most serious is rated moderate. Theoretically, neem leaf extract might increase the levels and clinical effects of CYP1A2 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Interaction report

Neem and Ethinyl Estradiol, Norethindrone, Ferrous Fumarate

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Neem interacts with whole categories of medication. Ethinyl Estradiol, Norethindrone, Ferrous Fumarate falls into 3 of those categories, so it can interact with Neem in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Ethinyl Estradiol, Norethindrone, Ferrous Fumarate

Ethinyl Estradiol, Norethindrone, Ferrous Fumarate falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Neem interacts with.

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that neem leaf extract inhibits CYP1A2 enzymes. So far, this reaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: your birth control pill (Loestrin Fe and similar) contains ethinyl estradiol, and that estrogen is partly broken down by a liver enzyme called CYP1A2. In test-tube studies, neem leaf extract seems to slow that same enzyme down. In theory, that could let estrogen levels drift a little higher, which might mean more of the usual estrogen-type side effects like nausea, breast tenderness, bloating, or headaches.

The important part: this has only been seen in lab dishes, never reported in real people, so the concern is very theoretical. Occasional culinary or skincare neem is unlikely to matter, while concentrated neem capsules are the bigger question mark. Before adding a neem supplement, just run it by your pharmacist or doctor.

References
  1. Amaeze O, Marques ES, Wei W, et al. Evaluation of Nigerian Medicinal Plants Extract on Human P-glycoprotein and Cytochrome P450 Enzyme Induction: Implications for Herb-drug Interaction. Curr Drug Metab. 2021;22(14):1103-1113. PubMed
Moderate

P-GLYCOPROTEIN SUBSTRATES

2 of 3

Ethinyl Estradiol, Norethindrone, Ferrous Fumarate also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, neem leaf extract might increase the levels and clinical effects of P-glycoprotein substrates.
In vitro research shows that neem leaf methanol extract inhibits renal P-glycoprotein transport activity. So far, this reaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

If you're taking a birth control pill like Loestrin Fe or Microgestin Fe along with neem, here's the honest picture. The hormones in your pill (ethinyl estradiol and norethindrone) are moved around the body partly by a transporter called P-glycoprotein. In lab dish studies, neem leaf extract seemed to slow that transporter down. In theory, that could let a little more hormone hang around, which might mean more of the usual things like nausea, breast tenderness, bloating, or spotting.

The key word is theoretical. This has only been seen in test tube and animal work, never reported in real people, so I wouldn't lose sleep over it. Still, since these pills matter, just mention your neem use to your pharmacist or doctor before combining them.

References
  1. Amaeze O, Marques ES, Wei W, et al. Evaluation of Nigerian Medicinal Plants Extract on Human P-glycoprotein and Cytochrome P450 Enzyme Induction: Implications for Herb-drug Interaction. Curr Drug Metab. 2021;22(14):1103-1113. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Ethinyl Estradiol, Norethindrone, Ferrous Fumarate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that neem leaf methanol extract inhibits CYP3A4 enzymes. So far, this reaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Your birth control pill contains ethinyl estradiol and norethindrone, which your liver clears using an enzyme called CYP3A4 (the iron, or ferrous fumarate, is just a supplement and isn't part of this issue). In lab dish studies, neem leaf extract slowed that same enzyme. If that happened in your body, it could let a bit more estrogen build up, which might mean more of the usual side effects like nausea, breast tenderness, bloating, or mood changes.

Here's the honest part: this is purely theoretical right now. It comes from test-tube research, not from real people, and it has never actually been reported in anyone taking the combo. Food-style or dental uses of neem are very unlikely to matter. Still, if you're thinking about neem supplements, run it past your pharmacist or doctor first.

References
  1. Amaeze O, Eng H, Horlbogen L, Varma MVS, Slitt A. Cytochrome P450 Enzyme Inhibition and Herb-Drug Interaction Potential of Medicinal Plant Extracts Used for Management of Diabetes in Nigeria. Eur J Drug Metab Pharmacokinet. 2021;46(3):437-450. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • 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.
Evidence the quality of the studies behind the rating (graded A–D)
  • 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.

Keep it in perspective

Neem Also Interacts With Other Medications

Neem has 1,013 moderate known drug interactions in our database — the Ethinyl Estradiol, Norethindrone, Ferrous Fumarate one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Neem

Covers the 2,830 medications we’ve checked against Neem. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Norethindrone, Ferrous Fumarate

This page covers Neem only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Norethindrone, Ferrous Fumarate page lists 240 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 196 moderate · 38 minor.

From our pharmacist’s overview on the Ethinyl Estradiol, Norethindrone, Ferrous Fumarate page

“If you take a birth control pill that combines ethinyl estradiol, norethindrone, and iron (Loestrin Fe, Estrostep Fe, Microgestin Fe), a few supplements can genuinely undermine it, and I want you to know which ones first. Six of the 240 ingredients on file carry a major rating.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl Estradiol, Norethindrone, Ferrous Fumarate interaction page

One more smart check

Taking Neem as Part of a Dietary Supplement Product? Check It for Interactions

We hold 288 real supplement products containing Neem, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Neem. Your product may carry other ingredients that interact with Ethinyl Estradiol, Norethindrone, Ferrous Fumarate too, on top of Neem — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Neem and Ethinyl Estradiol, Norethindrone, Ferrous Fumarate 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.

Supplement Neem
Top half

#402 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ethinyl Estradiol, Norethindrone, Ferrous Fumarate
Top 10%

#244 of 2,830 medications looked up here in the last 7 days

29 days ago today

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.

Supplement

About Neem

What is Neem?

Neem
  • Skin conditions
  • Dental and gum health
  • Antimicrobial and antiparasitic
  • Digestive upset
  • Blood sugar support
  • Insect repellent/pesticide

Neem is a tree from India used for centuries in traditional medicine, especially for skin, dental, and antimicrobial purposes. Some small studies are promising for oral health and skin, but high-quality human evidence is limited for most uses. Neem oil and seed extracts can be toxic if swallowed, especially in children, so use with caution and talk to your pharmacist or doctor first.

Read the full Neem monograph & all interactions
Keep checking

Other Drugs & Neem

Browse every other medication we’ve checked against Neem — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
1,013Moderate
0Minor
1,816No known interaction
Moderate

1,013 interactions

Showing 60 of 1,013 moderate interactions — see all 1,013 on the Neem page.

No interaction 1,816 drugs checked — show the list

We also checked Neem against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,816 medications checked with no known interaction — see the full Neem list.

Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

Keep exploring
Pharmacist Counseling Corner

Taking Neem and Ethinyl Estradiol, Norethindrone, Ferrous Fumarate Together: Common Questions

Can you take Neem with Ethinyl Estradiol, Norethindrone, Ferrous Fumarate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Neem and Ethinyl Estradiol, Norethindrone, Ferrous Fumarate?
Ethinyl Estradiol, Norethindrone, Ferrous Fumarate belongs to more than one drug category, and Neem interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Neem and Ethinyl Estradiol, Norethindrone, Ferrous Fumarate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Ethinyl Estradiol, Norethindrone, Ferrous Fumarate and Neem?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.