Drug & supplement interaction

L-citrulline + Ethinyl Estradiol, Norethindrone

Ethinyl Estradiol, Norethindrone brand names: Femhrt, Loestrin 21, Ovcon 35 21, Ovcon 50 28, Necon 0.5 35 21, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between L-citrulline and Ethinyl Estradiol, Norethindrone in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Ethinyl Estradiol, Norethindrone states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

L-citrulline and Ethinyl Estradiol, Norethindrone

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Ethinyl Estradiol, Norethindrone and L-citrulline in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

L-citrulline safety at a glance

L-citrulline overall Use caution Generally well tolerated in healthy adults, but long-term safety is not fully studied.
Pregnancy Avoid There is not enough safety data, so it is best to avoid supplements during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid supplemental use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Ethinyl Estradiol, Norethindrone and L-citrulline? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Ethinyl Estradiol, Norethindrone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Ethinyl Estradiol, Norethindrone is filed under 13 classifications — including progestin, contraceptive drugs, estrogens. L-citrulline has documented interactions with 2 drug classes — the most serious being antihypertensive drugs (moderate) and phosphodiesterase-5 inhibitors (moderate) — and none of Ethinyl Estradiol, Norethindrone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

L-citrulline Does Interact With Other Medications

L-citrulline has 178 moderate known drug interactions in our database — Ethinyl Estradiol, Norethindrone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 178 No known interaction 2,652 (incl. Ethinyl Estradiol, Norethindrone)
Taking anything else?

Check Another of Your Medications Against L-citrulline

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

What to actually watch for

No Interaction Found — But Data Suggests L-citrulline and Ethinyl Estradiol, Norethindrone May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    L-citrulline

    “Orally, 2 of 25 patients with pulmonary hypertension reported cough while taking 1 gram of powdered L-citrulline in water daily.”

    L-citrulline · Natural Medicines adverse-effect record, reported in cough.

    1 source cited
    1. 94963. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed

    “Orally, 2 of 25 patients with pulmonary hypertension reported increased urinary frequency and edema while taking 1 gram of powdered L-citrulline in water daily.”

    L-citrulline · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 94963. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed

    Ethinyl Estradiol, Norethindrone

    Listed in the ADVERSE REACTIONS section of the FDA label for Ethinyl Estradiol, Norethindrone. Read the label on DailyMed ›

Reported for L-citrulline but not commonly for Ethinyl Estradiol, Norethindrone: stomach upset, heartburn, swelling and cough.

Effects for Ethinyl Estradiol, Norethindrone come from the ADVERSE REACTIONS section of its FDA label; effects for L-citrulline come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Ethinyl Estradiol, Norethindrone Products Have a Food Rule — L-citrulline Should Not Break It

At least one FDA label for a product containing Ethinyl Estradiol, Norethindrone says to take it with food. If you take L-citrulline on an empty stomach out of habit, keep them separate — and take Ethinyl Estradiol, Norethindrone with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Ethinyl Estradiol, Norethindrone products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Tablets should be taken regularly with a meal or at bedtime.

From the Dosage and Administration section of the FDA label we read for Ethinyl Estradiol, Norethindrone — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About L-citrulline or Ethinyl Estradiol, Norethindrone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers L-citrulline or Ethinyl Estradiol, Norethindrone, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Norethindrone

This page covers L-citrulline only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Norethindrone 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 page

“If you take a birth control pill or hormone therapy containing ethinyl estradiol and norethindrone (Loestrin, Femhrt, and others), a few supplements can genuinely undermine it, so read this page with care. Six of the 240 ingredients on file are rated major, and those six come first.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl Estradiol, Norethindrone interaction page

One more smart check

Taking L-citrulline as Part of a Dietary Supplement Product? Check It for Interactions

We hold 63 real supplement products containing L-citrulline, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-citrulline. Even though L-citrulline itself has no known interaction with Ethinyl Estradiol, Norethindrone, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where L-citrulline and Ethinyl Estradiol, Norethindrone 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 L-citrulline
Top half

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

29 days ago today
Medication Ethinyl Estradiol, Norethindrone
Top 25%

#442 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every L-citrulline reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The L-citrulline and Ethinyl Estradiol, Norethindrone records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About L-citrulline

What is L-citrulline?

L-citrulline
  • Exercise performance
  • Muscle soreness and fatigue
  • Blood flow and circulation
  • Erectile dysfunction
  • Blood pressure support

L-citrulline is an amino acid that the body turns into L-arginine to help make nitric oxide, which relaxes blood vessels and may improve blood flow. It is popular for exercise performance and circulation, but the evidence is mixed and most benefits are modest. It appears generally well tolerated, but talk to your pharmacist or doctor before starting, especially if you have a health condition or are pregnant.

Amino acid (made by the body and found in foods; supplements are usually made by fermentation) · Powder, capsules, tablets; also sold as citrulline malate

An interaction check asks whether these two react with each other — it does not ask whether L-citrulline is a good idea for someone in your situation. Here is what our L-citrulline record says about it on its own.

L-citrulline: dosing

There is no official standardized dose of L-citrulline, and the right amount can depend on the form (plain L-citrulline versus citrulline malate) and the reason for use. Doses used in studies vary widely.Because of this, the best approach is to follow the directions on the product label and start with the lowest suggested amount.

From our L-citrulline monograph — the full record covers uses, side effects and every documented interaction.

Read the full L-citrulline monograph & all interactions
Keep checking

Other Drugs & L-citrulline

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

0Major
178Moderate
0Minor
2,651No known interaction
178 Moderate 2,651 No interaction
Moderate

178 interactions

Showing 60 of 178 moderate interactions — see all 178 on the L-citrulline page.

No interaction 2,651 drugs checked — show the list

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

Showing the 60 most looked-up of 2,651 medications checked with no known interaction — see the full L-citrulline list.

See the full L-citrulline interactions page
See every supplement checked against Ethinyl Estradiol, Norethindrone, ranked by severity
Evidence & sources

L-citrulline References

The 8 references that drive our L-citrulline monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Cheng JW, Balwin SN. L-arginine in the management of cardiovascular diseases. Ann Pharmacother 2001;35:755-64. PubMed
  2. Schwedhelm E, Maas R, Freese R, et al. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism. Br J Clin Pharmacol 2008;65:51-9. PubMed
  3. Romero MJ, Platt DH, Caldwell RB, Caldwell RW. Therapeutic use of citrulline in cardiovascular disease. Cardiovasc Drug Rev 2006;24:275-90. PubMed
  4. Balderas-Munoz K, Castillo-Martínez L, Orea-Tejeda A, et al. Improvement of ventricular function in systolic heart failure patients with oral L-citrulline supplementation. Cardiol J 2012;19:612-7. PubMed
  5. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed
  6. Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res 2010;24:1215-22. PubMed
  7. Mirenayat MS, Moradi S, Mohammadi H, Rouhani MH. Effect of L-citrulline supplementation on blood pressure: a systematic review and meta-analysis of clinical trials. Curr Hypertens Rep. 2018;20(11):98. PubMed
  8. Xu Z, Liu C, Liu S, Zhou Z. Comparison of efficacy and safety of daily oral L-arginine and PDE5Is alone or combination in treating erectile dysfunction: A systematic review and meta-analysis of randomised controlled trials. Andrologia. 2021:e14007. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking L-citrulline and Ethinyl Estradiol, Norethindrone Together: Common Questions

Is it safe to take L-citrulline with Ethinyl Estradiol, Norethindrone?
We do not list a known interaction between L-citrulline and Ethinyl Estradiol, Norethindrone. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do L-citrulline and Ethinyl Estradiol, Norethindrone have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take L-citrulline and Ethinyl Estradiol, Norethindrone at the same time of day?
At least one FDA label for a product containing Ethinyl Estradiol, Norethindrone says to take it with food. If you take L-citrulline on an empty stomach out of habit, keep them separate and take Ethinyl Estradiol, Norethindrone with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Ethinyl Estradiol, Norethindrone products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the L-citrulline and Ethinyl Estradiol, Norethindrone combination checked?
Interactions in our licensed database are recorded against drug classes. Ethinyl Estradiol, Norethindrone is filed under 13 classifications, and L-citrulline has documented interactions with 2 drug classes — none of Ethinyl Estradiol, Norethindrone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does L-citrulline interact with any other medications?
Yes. L-citrulline has 178 documented drug interactions in our database — Ethinyl Estradiol, Norethindrone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Ethinyl Estradiol, Norethindrone interact with any supplements?
Yes. Ethinyl Estradiol, Norethindrone has documented interactions with 240 supplements in our database — L-citrulline is not one of them. The Ethinyl Estradiol, Norethindrone interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

L-citrulline monograph Uses, safety profile, and every drug interaction in one place Ethinyl Estradiol, Norethindrone supplement interactions Every supplement checked against Ethinyl Estradiol, Norethindrone, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Ethinyl Estradiol, Norethindrone and L-citrulline?

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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.