Drug & supplement interaction

L-arginine + Methylene Blue

Methylene Blue brand names: Urolene Blue, Provayblue.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between L-arginine and Methylene Blue 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 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-arginine and Methylene Blue

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 Methylene Blue and L-arginine 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-arginine safety at a glance

L-arginine overall Use caution Often well tolerated short-term, but it can lower blood pressure and may not be safe for everyone.

Pregnancy Possibly Safe When used orally and appropriately, short-term. L-arginine 12 grams daily for 2 days has been used with apparent safety in pregnancy during the third trimester.... Read the full pregnancy detail

Breastfeeding Not established There is not enough reliable information, so it is best avoided unless your doctor advises otherwise.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Methylene Blue and L-arginine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Methylene Blue

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methylene Blue is filed under 3 classifications — serotonergic drugs, serotonergic drugs, oral drugs. L-arginine has documented interactions with 9 drug classes — the most serious being ace inhibitors (aceis) (moderate), angiotensin receptor blockers (arbs) (moderate) and anticoagulant/antiplatelet drugs (moderate) — and none of Methylene Blue’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-arginine Does Interact With Other Medications

L-arginine has 395 moderate, 8 minor known drug interactions in our database — Methylene Blue isn’t one of them. If you take anything else, check it against the full list below.

Moderate 395 Minor 8 No known interaction 2,427 (incl. Methylene Blue)

Taking anything else?

Check Another of Your Medications Against L-arginine

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

What to actually watch for

No Interaction Found — But Data Suggests L-arginine and Methylene Blue May Share Several of the Same Side Effects

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.

Diarrhea / Nausea Additional detail
L-arginine
“Orally, L-arginine has been reported to cause nausea, diarrhea, vomiting, dyspepsia, gastrointestinal discomfort, and bloating.

Orally, L-arginine has been reported to cause esophagitis in at least six adolescents. Symptoms, which included pain and dysphagia, occurred within 1-3 months of treatment in most cases. There are at least two cases of acute pancreatitis possibly associated with oral L-arginine.”

L-arginine · Natural Medicines adverse-effect record, reported in diarrhea.
6 sources cited

1363. Clarkson P, Adams MR, Powe AJ, et al. Oral L-arginine improves endothelium-dependent dilation in hypercholesterolemic young adults. J Clin Invest 1996;97:1989-94. PubMed

31855. Cartledge, J. J., Davies, A. M., and Eardley, I. A randomized double-blind placebo-controlled crossover trial of the efficacy of L-arginine in the treatment of interstitial cystitis. BJU.Int. 2000;85(4):421-426.

31871. Nagaya, N., Uematsu, M., Oya, H., Sato, N., Sakamaki, F., Kyotani, S., Ueno, K., Nakanishi, N., Yamagishi, M., and Miyatake, K. Short-term oral administration of L-arginine improves hemodynamics and exercise capacity in patients with precapillary pulmona

31972. Savoye, G., Jemaa, Y., Mosni, G., Savoye-Collet, C., Morcamp, P., Dechelotte, P., Bouin, M., Denis, P., and Ducrotte, P. Effects of intragastric L-arginine administration on proximal stomach tone under basal conditions and after an intragastric diet. Dig PubMed

31978. Facchinetti, F., Saade, G. R., Neri, I., Pizzi, C., Longo, M., and Volpe, A. L-arginine supplementation in patients with gestational hypertension: a pilot study. Hypertens.Pregnancy. 2007;26(1):121-130. PubMed

32261. Khan, F., Litchfield, S. J., McLaren, M., Veale, D. J., Littleford, R. C., and Belch, J. J. Oral L-arginine supplementation and cutaneous vascular responses in patients with primary Raynaud's phenomenon. Arthritis Rheum. 1997;40(2):352-357.
Methylene Blue

Listed in the ADVERSE REACTIONS section of the FDA label for Methylene Blue. Read the label on DailyMed ›
Headache Additional detail
L-arginine
“Orally, L-arginine has been associated with headache, insomnia, fatigue, and vertigo.”

L-arginine · Natural Medicines adverse-effect record, reported in cluster headache.
6 sources cited

31855. Cartledge, J. J., Davies, A. M., and Eardley, I. A randomized double-blind placebo-controlled crossover trial of the efficacy of L-arginine in the treatment of interstitial cystitis. BJU.Int. 2000;85(4):421-426.

31955. Mansoor, J. K., Morrissey, B. M., Walby, W. F., Yoneda, K. Y., Juarez, M., Kajekar, R., Severinghaus, J. W., Eldridge, M. W., and Schelegle, E. S. L-arginine supplementation enhances exhaled NO, breath condensate VEGF, and headache at 4,342 m. High Alt.M

32261. Khan, F., Litchfield, S. J., McLaren, M., Veale, D. J., Littleford, R. C., and Belch, J. J. Oral L-arginine supplementation and cutaneous vascular responses in patients with primary Raynaud's phenomenon. Arthritis Rheum. 1997;40(2):352-357.

91197. Vadillo-Ortega F, Perichart-Perera O, Espino S, et al. Effect of supplementation during pregnancy with L-arginine and antioxidant vitamins in medical food on pre-eclampsia in high risk population: randomised controlled trial. BMJ. 2011 May 19;342:d2901. PubMed

102587. Gallo L, Pecoraro S, Sarnacchiaro P, Silvani M, Antonini G. The daily therapy with L-arginine 2,500 mg and tadalafil 5 mg in combination and in monotherapy for the treatment of erectile dysfunction: A prospective, randomized multicentre study. Sex Med. 20 PubMed

102592. El-Wakeel LM, Fouad FA, Saleem MD, Saber-Khalaf M. Efficacy and tolerability of sildenafil/l-arginine combination relative to sildenafil alone in patients with organic erectile dysfunction. Andrology. 2020;8(1):143-147.
Methylene Blue

Listed in the ADVERSE REACTIONS section of the FDA label for Methylene Blue. Read the label on DailyMed ›

Reported for L-arginine but not commonly for Methylene Blue: stomach upset, pancreatitis, an allergic reaction and back pain.

Effects for Methylene Blue come from the ADVERSE REACTIONS section of its FDA label; effects for L-arginine 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.

Special populations

L-arginine in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When used orally and appropriately, short-term. L-arginine 12 grams daily for 2 days has been used with apparent safety in pregnancy during the third trimester. L-arginine 3 grams daily has been taken safely during the second and/or third trimesters. ...when used intravenously and appropriately, short-term. Intravenous L-arginine 20-30 grams daily has been used safely in pregnancy for up to 5 days.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About L-arginine or Methylene Blue

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-arginine or Methylene Blue, 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:

Which Medications Interact With Nitric Oxide Supplements? Answered by Dr. Brian Staiger, PharmD · August 2026 ›

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 Methylene Blue

This page covers L-arginine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylene Blue page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Methylene Blue page

“The pairing I would worry about first with methylene blue (Urolene Blue, Provayblue) is anything that raises serotonin, and lithium heads that group with a major rating. Methylene blue inhibits monoamine oxidase A, the enzyme that breaks serotonin down, so combining it with serotonin-boosting supplements can tip someone into serotonin…”

Reviewed by 2 · Jul 18, 2026

Open the Methylene Blue interaction page

One more smart check

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

We hold 26 real supplement products containing L-arginine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-arginine. Even though L-arginine itself has no known interaction with Methylene Blue, 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-arginine and Methylene Blue 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-arginine

Steady interest

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

29 days ago today

Medication Methylene Blue

Top 5%

#53 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-arginine reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The L-arginine and Methylene Blue records this page draws on were last updated July 11, 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About L-arginine

What is L-arginine?

High blood pressure
Erectile dysfunction
Athletic performance
Chest pain (angina)
Improving blood flow

L-arginine is an amino acid that the body uses to make nitric oxide, a substance that helps blood vessels relax and widen. It is popularly used for blood pressure, erectile dysfunction, and exercise, but the evidence is mixed and stronger for some uses than others. It is generally well tolerated in healthy adults, but talk with a pharmacist or doctor before using it, especially if you have heart problems or take other medicines.

Amino acid (made by the body and found in protein-rich foods) · Capsules, tablets, powders, sustained-release products

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

L-arginine: dosing

There is no single official dose of L-arginine that fits all uses, and the amounts used in studies have varied widely. Because of this, a standardized dose is often not established.The best approach is to follow the directions on the product label and to start with the lowest reasonable amount. A pharmacist can help you decide whether a product and dose make sense for your situation.Do not assume that more is better. Higher doses are more likely to cause stomach upset and other side effects.

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

Read the full L-arginine monograph & all interactions

Keep checking

Other Drugs & L-arginine

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

0Major

395Moderate

8Minor

2,426No known interaction

395 Moderate 8 Minor 2,426 No interaction

Moderate

395 interactions

Showing 60 of 395 moderate interactions — see all 395 on the L-arginine page.

Minor

8 interactions

No interaction 2,426 drugs checked — show the list

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

Showing the 60 most looked-up of 2,426 medications checked with no known interaction — see the full L-arginine list.

See the full L-arginine interactions page

See every supplement checked against Methylene Blue, ranked by severity

Evidence & sources

L-arginine References

The 66 references that drive our L-arginine 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.

Sapienza MA, Kharitonov SA, Horvath I, et al. Effect of inhaled L-arginine on exhaled nitric oxide in normal and asthmatic subjects. Thorax 1998;53:172-5.
Clarkson P, Adams MR, Powe AJ, et al. Oral L-arginine improves endothelium-dependent dilation in hypercholesterolemic young adults. J Clin Invest 1996;97:1989-94. PubMed
Tenenbaum A, Fisman EZ, Motro M. L-arginine: Rediscovery in progress. Cardiology 1998;90:153-9.
Brittenden J, Park KGM, Heys SD, et al. L-Arginine stimulates host defenses in patients with breast cancer. Surgery 1994;115:205-12.
Korting GE, Smith SD, Wheeler MA, et al. A randomized double-blind trial of oral L-arginine for treatment of interstitial cystitis. J Urol 1999;161:558-65. DOI
Rector TS, Bank AJ, Mullen KA, et al. Randomized, double-blind, placebo-controlled study of supplemental oral L-arginine in patients with heart failure. Circulation 1996;93:2135-41.
Siani A, Pagano E, Iacone R, et al. Blood pressure and metabolic changes during dietary L-arginine supplementation in humans. Am J Hypertens 2000;13:547-51. PubMed
Cheng JW, Balwin SN. L-arginine in the management of cardiovascular diseases. Ann Pharmacother 2001;35:755-64. PubMed
Wallace AW, Tom WL. Interaction of L-arginine and phosphodiesterase inhibitors in vasodilation of the porcine internal mammary artery. Anesth Analg 2000;90:840-6. DOI
Huynh NT, Tayek JA. Oral arginine reduces systemic blood pressure in type 2 diabetes: its potential role in nitric oxide generation. J Am Coll Nutr 2002;21:422-7.. PubMed
Staff AC, Berge L, Haugen G, et al. Dietary supplementation with L-arginine or placebo in women with pre-eclampsia. Acta Obstet Gynecol Scand 2004;83:103-7.
Resnick DJ, Softness B, Murphy AR, et al. Case report of an anaphylactoid reaction to arginine. Ann Allergy Asthma Immunol 2002;88:67-8. PubMed
Anon. Arginine hydrochloride injection (marketed as R-Gene 10). FDA Drug Safety Newsletter 2009;2(2):16-18. Available at: www.fda.gov/Drugs/DrugSafety/DrugSafetyNewsletter/default.htm.
Higashi Y, Oshima T, Sasaki S, et. al. Angiotensin-converting enzyme inhibition, but not calcium antagonism, improves a response of the renal vasculature to L-arginine in patients with essential hypertension. Hypertension. 1998 Jul;32(1):16-24.
Facchinetti, F., Longo, M., Piccinini, F., Neri, I., and Volpe, A. L-arginine infusion reduces blood pressure in preeclamptic women through nitric oxide release. J Soc Gynecol.Investig. 1999;6(4):202-207. DOI
de Gouw, H. W., Verbruggen, M. B., Twiss, I. M., and Sterk, P. J. Effect of oral L-arginine on airway hyperresponsiveness to histamine in asthma. Thorax 1999;54(11):1033-1035. PubMed
Komers, R., Komersova, K., Kazdova, L., Ruzickova, J., and Pelikanova, T. Effect of ACE inhibition and angiotensin AT1 receptor blockade on renal and blood pressure response to L-arginine in humans. J Hypertens. 2000;18(1):51-59. PubMed
Cartledge, J. J., Davies, A. M., and Eardley, I. A randomized double-blind placebo-controlled crossover trial of the efficacy of L-arginine in the treatment of interstitial cystitis. BJU.Int. 2000;85(4):421-426.
Sozykin, A. V., Noeva, E. A., Balakhonova, T. V., Pogorelova, O. A., and Men'shikov, M. I. [Effect of L-arginine on platelet aggregation, endothelial function adn exercise tolerance in patients with stable angina pectoris]. Ter.Arkh. 2000;72(8):24-27.
Nagaya, N., Uematsu, M., Oya, H., Sato, N., Sakamaki, F., Kyotani, S., Ueno, K., Nakanishi, N., Yamagishi, M., and Miyatake, K. Short-term oral administration of L-arginine improves hemodynamics and exercise capacity in patients with precapillary pulmona
Stokes, G. S., Barin, E. S., Gilfillan, K. L., and Kaesemeyer, W. H. Interactions of L-arginine, isosorbide mononitrate, and angiotensin II inhibitors on arterial pulse wave. Am J Hypertens. 2003;16(9 Pt 1):719-724.
Park, K. G., Heys, S. D., Blessing, K., Kelly, P., McNurlan, M. A., Eremin, O., and Garlick, P. J. Stimulation of human breast cancers by dietary L-arginine. Clin.Sci.(Lond) 1992;82(4):413-417.
Palloshi, A., Fragasso, G., Piatti, P., Monti, L. D., Setola, E., Valsecchi, G., Galluccio, E., Chierchia, S. L., and Margonato, A. Effect of oral L-arginine on blood pressure and symptoms and endothelial function in patients with systemic hypertension,
Schlaich, M. P., Ahlers, B. A., Parnell, M. M., and Kaye, D. M. beta-Adrenoceptor-mediated, nitric-oxide-dependent vasodilatation is abnormal in early hypertension: restoration by L-arginine. J Hypertens. 2004;22(10):1917-1925. PubMed
Neri, I., Blasi, I., and Facchinetti, F. Effects of acute L-arginine infusion on non-stress test in hypertensive pregnant women. J Matern.Fetal Neonatal Med. 2004;16(1):23-26. PubMed
Rytlewski, K., Olszanecki, R., Korbut, R., and Zdebski, Z. Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia. Eur.J Clin.Invest 2005;35(1):32-37.
Mansoor, J. K., Morrissey, B. M., Walby, W. F., Yoneda, K. Y., Juarez, M., Kajekar, R., Severinghaus, J. W., Eldridge, M. W., and Schelegle, E. S. L-arginine supplementation enhances exhaled NO, breath condensate VEGF, and headache at 4,342 m. High Alt.M
Neri, I., Jasonni, V. M., Gori, G. F., Blasi, I., and Facchinetti, F. Effect of L-arginine on blood pressure in pregnancy-induced hypertension: a randomized placebo-controlled trial. J Matern.Fetal Neonatal Med. 2006;19(5):277-281.
Lucotti, P., Setola, E., Monti, L. D., Galluccio, E., Costa, S., Sandoli, E. P., Fermo, I., Rabaiotti, G., Gatti, R., and Piatti, P. Beneficial effects of a long-term oral L-arginine treatment added to a hypocaloric diet and exercise training program in
Savoye, G., Jemaa, Y., Mosni, G., Savoye-Collet, C., Morcamp, P., Dechelotte, P., Bouin, M., Denis, P., and Ducrotte, P. Effects of intragastric L-arginine administration on proximal stomach tone under basal conditions and after an intragastric diet. Dig PubMed
Facchinetti, F., Saade, G. R., Neri, I., Pizzi, C., Longo, M., and Volpe, A. L-arginine supplementation in patients with gestational hypertension: a pilot study. Hypertens.Pregnancy. 2007;26(1):121-130. PubMed
Jovanovic, A., Gerrard, J., and Taylor, R. The second-meal phenomenon in type 2 diabetes. Diabetes Care 2009;32(7):1199-1201. PubMed
Fontanive P, Saponati G, Iurato A, et al. Effects of L-arginine on the Minnesota Living with Heart Failure Questionnaire quality-of-life score in patients with chronic systolic heart failure. Med.Sci.Monit. 2009;15:CR606-11.
Doutreleau, S., Rouyer, O., Di, Marco P., Lonsdorfer, E., Richard, R., Piquard, F., and Geny, B. L-arginine supplementation improves exercise capacity after a heart transplant. Am J Clin.Nutr. 2010;91(5):1261-1267. PubMed
Ast, J., Jablecka, A., Bogdanski, P., Smolarek, I., Krauss, H., and Chmara, E. Evaluation of the antihypertensive effect of L-arginine supplementation in patients with mild hypertension assessed with ambulatory blood pressure monitoring. Med.Sci.Monit. 2
Saleh, A. I., Abdel Maksoud, S. M., El-Maraghy, S. A., and Gad, M. Z. Protective effect of L-arginine in experimentally induced myocardial ischemia: comparison with aspirin. J Cardiovasc.Pharmacol.Ther 2011;16(1):53-62. PubMed
Dong, J. Y., Qin, L. Q., Zhang, Z., Zhao, Y., Wang, J., Arigoni, F., and Zhang, W. Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials. Am.Heart J 2011;162(6):959-965. PubMed
Hertz, P. and Richardson, J. A. Arginine-induced hyperkalemia in renal failure patients. Arch.Intern.Med. 1972;130(5):778-780. DOI
Bushinsky, D. A. and Gennari, F. J. Life-threatening hyperkalemia induced by arginine. Ann.Intern.Med. 1978;89(5 Pt 1):632-634. PubMed
Adams, M. R., Forsyth, C. J., Jessup, W., Robinson, J., and Celermajer, D. S. Oral L-arginine inhibits platelet aggregation but does not enhance endothelium-dependent dilation in healthy young men. J Am Coll.Cardiol 1995;26(4):1054-1061. PubMed
Dell'Omo, G., Catapano, G., Ebel, M., Gazzano, A., Ducci, M., Del, Chicca M., Clerico, A., and Pedrinelli, R. [Pressor, renal and endocrine effects of systemic infusion of L-arginine in hypertensive patients]. Ann.Ital Med.Int. 1995;10(2):107-112.
Higashi, Y., Oshima, T., Ozono, R., Watanabe, M., Matsuura, H., and Kajiyama, G. Effects of L-arginine infusion on renal hemodynamics in patients with mild essential hypertension. Hypertension 1995;25(4 Pt 2):898-902.
Bode-Boger, S. M., Boger, R. H., Creutzig, A., Tsikas, D., Gutzki, F. M., Alexander, K., and Frolich, J. C. L-arginine infusion decreases peripheral arterial resistance and inhibits platelet aggregation in healthy subjects. Clin.Sci.(Lond) 1994;87(3):303
Marfella, R., Acampora, R., Verrazzo, G., Ziccardi, P., De, Rosa N., Giunta, R., and Giugliano, D. Metformin improves hemodynamic and rheological responses to L-arginine in NIDDM patients. Diabetes Care 1996;19(9):934-939. PubMed
Giugliano, D., Marfella, R., Verrazzo, G., Acampora, R., Coppola, L., Cozzolino, D., and D'Onofrio, F. The vascular effects of L-Arginine in humans. The role of endogenous insulin. J Clin.Invest 2-1-1997;99(3):433-438. PubMed
Khan, F., Litchfield, S. J., McLaren, M., Veale, D. J., Littleford, R. C., and Belch, J. J. Oral L-arginine supplementation and cutaneous vascular responses in patients with primary Raynaud's phenomenon. Arthritis Rheum. 1997;40(2):352-357.
Wolf, A., Zalpour, C., Theilmeier, G., Wang, B. Y., Ma, A., Anderson, B., Tsao, P. S., and Cooke, J. P. Dietary L-arginine supplementation normalizes platelet aggregation in hypercholesterolemic humans. J Am Coll.Cardiol 3-1-1997;29(3):479-485. PubMed
Schellong, S. M., Boger, R. H., Burchert, W., Bode-Boger, S. M., Galland, A., Frolich, J. C., Hundeshagen, H., and Alexander, K. Dose-related effect of intravenous L-arginine on muscular blood flow of the calf in patients with peripheral vascular disease
Marietta, M., Facchinetti, F., Neri, I., Piccinini, F., Volpe, A., and Torelli, G. L-arginine infusion decreases platelet aggregation through an intraplatelet nitric oxide release. Thromb.Res 10-15-1997;88(2):229-235. PubMed
Bauer JD, Isenring E, Waterhouse M. The effectiveness of a specialised oral nutrition supplement on outcomes in patients with chronic wounds: a pragmatic randomised study. J Hum Nutr Diet. 2013 Oct;26(5):452-8. PubMed
Vadillo-Ortega F, Perichart-Perera O, Espino S, et al. Effect of supplementation during pregnancy with L-arginine and antioxidant vitamins in medical food on pre-eclampsia in high risk population: randomised controlled trial. BMJ. 2011 May 19;342:d2901. PubMed
Camarena Pulido EE, García Benavides L, Panduro Barón JG, et al. Efficacy of L-arginine for preventing preeclampsia in high-risk pregnancies: A double-blind, randomized, clinical trial. Hypertens Pregnancy. 2016;35(2):217-25. PubMed
Yokota T, Hamauchi S, Yoshida Y, et al. A phase II study of HMB/Arg/Gln against oral mucositis induced by chemoradiotherapy for patients with head and neck cancer. Support Care Cancer. 2018;26(9):3241-3248. PubMed
Binet Q, Dufour I, Agneessens E, et al. The second case of a young man with L-arginine-induced acute pancreatitis. Clin J Gastroenterol. 2018;11(5):424-427. PubMed
El Taieb M, Hegazy E, Ibrahim A. Daily oral l-arginine plus tadalafil in diabetic patients with erectile dysfunction: A double-blinded, randomized, controlled clinical trial. J Sex Med. 2019;16(9):1390-1397.
Gallo L, Pecoraro S, Sarnacchiaro P, Silvani M, Antonini G. The daily therapy with L-arginine 2,500 mg and tadalafil 5 mg in combination and in monotherapy for the treatment of erectile dysfunction: A prospective, randomized multicentre study. Sex Med. 20 PubMed
de la Parra PR, González-Cruz MÁ, Ferreiro-Marin A, Casaubón-Garcín PR. L-arginine-induced esophagitis, report of six cases. Bol Med Hosp Infant Mex. 2020;77(1):38-41. PubMed
El-Wakeel LM, Fouad FA, Saleem MD, Saber-Khalaf M. Efficacy and tolerability of sildenafil/l-arginine combination relative to sildenafil alone in patients with organic erectile dysfunction. Andrology. 2020;8(1):143-147.
Abu El-Hamd M, Hegazy EM. Comparison of the clinical efficacy of daily use of L-arginine, tadalafil and combined L-arginine with tadalafil in the treatment of elderly patients with erectile dysfunction. Andrologia. 2020;52(7):e13640. PubMed
Liao SY, Showalter MR, Linderholm AL, et al. l-Arginine supplementation in severe asthma. JCI Insight. 2020;5(13):e137777. PubMed
Yousefi Rad E, Nazarian B, Saboori S, Falahi E, Hekmatdoost A. Effects of l-arginine supplementation on glycemic profile: Evidence from a systematic review and meta-analysis of clinical trials. J Integr Med. 2020;18(4):284-291. PubMed
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
Goto E. Effects of prenatal oral L-arginine on birth outcomes: a meta-analysis. Sci Rep 2021;11(1):22748. PubMed
Monari F, Menichini D, Pignatti L, Basile L, Facchinetti F, Neri I. Effect of L-arginine supplementation in pregnant women with chronic hypertension and previous placenta vascular disorders receiving Aspirin prophylaxis: a randomized control trial. Minerv PubMed
Li H, Liu Q, Zou Z, et al. L-arginine supplementation to mitigate cardiovascular effects of walking outside in the context of traffic-related air pollution in participants with elevated blood pressure: A randomized, double-blind, placebo-controlled trial. PubMed
Shiraseb F, Asbaghi O, Bagheri R, Wong A, Figueroa A, Mirzaei K. The Effect of L-arginine Supplementation On Blood Pressure in Adults: A Systematic Review and Dose-response Meta-analysis of Randomized Clinical Trials. Adv Nutr 2021. 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-arginine and Methylene Blue Together: Common Questions

Is it safe to take L-arginine with Methylene Blue?

We do not list a known interaction between L-arginine and Methylene Blue. 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-arginine and Methylene Blue have any of the same side effects?

Yes — our sources link each of them separately to 3 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.

How was the L-arginine and Methylene Blue combination checked?

Interactions in our licensed database are recorded against drug classes. Methylene Blue is filed under 3 classifications, and L-arginine has documented interactions with 9 drug classes — none of Methylene Blue'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-arginine interact with any other medications?

Yes. L-arginine has 403 documented drug interactions in our database — Methylene Blue 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 Methylene Blue interact with any supplements?

Yes. Methylene Blue has documented interactions with 38 supplements in our database — L-arginine is not one of them. The Methylene Blue interaction page linked on this page lists every one, ranked by severity.

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.