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Dietary supplement

L-Citrulline 750 mg Ingredients & Drug Interactions

by Protocol For Life Balance

Capsule Category: Amino Acid/protein
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Citrulline 750 mg is a dietary supplement by Protocol For Life Balance with 1 active ingredient. Its ingredients are commonly taken for exercise performance, muscle soreness and fatigue, blood flow and circulation.Based on those ingredients, 178 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Citrulline. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of L-Citrulline 750 mg by Protocol For Life Balance

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: 750 mg of L-citrulline per capsule. L-citrulline is an amino acid your body can convert to L-arginine, which plays a role in blood vessel function and blood flow.

The capsule also holds inactive ingredients—gelatin (the capsule material itself), calcium carbonate, magnesium oxide, and magnesium stearate—which are fillers and binders that have no therapeutic role.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see L-citrulline's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: Healthy nitrogen balance and protein metabolism.
  • We looked for evidence on: Muscle strength, Sarcopenia, muscle protein synthesis, nitrogen retention.
  • The closest evidence on file: L-citrulline is rated "Possibly Ineffective" for Sarcopenia (Natural Medicines).
  • Also on file: L-citrulline is rated "Insufficient Reliable Evidence To Rate" for Muscle strength.

L-citrulline is rated possibly effective for athletic performance—some evidence suggests it may support exercise endurance or muscle function, though more research would strengthen that claim. For sarcopenia (age-related muscle loss), it's rated possibly ineffective based on available data.

For cardiovascular disease, heart failure, Reye syndrome, and diabetes, the evidence isn't established in our data—there's either too little research or it's of too low a quality to rate the supplement's usefulness. If you're considering L-citrulline for any of these conditions, talk it over with your doctor or pharmacist.

The evidence, ingredient by ingredient L-citrulline

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

L-citrulline is generally well tolerated in healthy adults, but long-term safety hasn't been fully studied. The most common side effects are gastrointestinal—discomfort, heartburn, and stomach upset.

A small number of people with pulmonary hypertension reported cough while taking the supplement. There isn't enough safety data to recommend L-citrulline during pregnancy, so avoid supplemental use if you're pregnant.

Safety while breastfeeding is also unknown, so skip it if you're nursing. If you're planning pregnancy or breastfeeding and are interested in taking L-citrulline for another reason, talk with your doctor or pharmacist about your individual situation.

Side effects, ingredient by ingredient L-citrulline

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — L-citrulline.
  • The most serious interaction on file is rated Moderate.
  • For scale: 178 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take this product, double-check your blood pressure medications (antihypertensives) and any erectile dysfunction drugs (phosphodiesterase-5 inhibitors) against the tool on this page. Both drug types carry a Moderate interaction risk with L-citrulline due to additive blood-vessel-widening and blood-pressure-lowering effects.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

L-Citrulline 750 mg may be worth considering if you're looking for a supplement for athletic performance and you don't take blood pressure medications or erectile dysfunction drugs. If you're on either of those medication types, check your specific drugs first—the interaction risk is real and dose-dependent.

Talk with your doctor or pharmacist before starting, especially if you have heart or blood pressure concerns.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Oct 25, 2012.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about L-Citrulline 750 mg, straight from the product label.

Brand Protocol For Life Balance
Barcode (UPC) 707359101036
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD Oct 25, 2012
DSLD ID 14874
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for L-Citrulline 750 mg by Protocol For Life Balance, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
4 Capsule(s)
Maximum serving Sizes:
4 Capsule(s)
Servings per container
45
UPC/BARCODE
707359101036
IngredientAmount% DV
L-Citrulline3 g--

Other ingredients: Gelatin, Calcium Carbonate, Magnesium Oxide, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

For more information on this product go to www.protocolforlife.com/P0103.

Healthy Nitrogen Balance Supports Protein Metabolism

Please Recycle.

Formulated by doctors and clinical scientists exclusively for licensed healthcare practitioners.

HOW IT WORKS: L-Citrulline is a naturally occurring non-essential amino acid. Although LCitrulline is not used in protein synthesis, it has several important functions with respect to amino acid and protein metabolism. As a precursor to Arginine, L-Citrulline is involved in the formation of urea in the liver. The synthesis and elimination of urea is essential for removing toxic protein metabolites from the body. In addition, L-Citrulline facilitates protein synthesis for muscle tissue retention and helps to maintain healthy nitrogen balance.

General

CODE P0103 V1

FDA Statement of Identity

A Dietary Supplement

Seals/Symbols

GMP

Formulation

Contains no sugar, salt, yeast, wheat, gluten, soy, milk, egg, shellfish or preservatives.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.

Suggested/Recommended/Usage/Directions

SUGGESTED USAGE: As a dietary supplement, take 4 capsules 1 to 2 times daily or as directed by your healthcare practitioner.

Precautions

CAUTIONS/INTERACTIONS: Watermelon contains high levels of L-Citrulline. Avoid excessive consumption of watermelon while using a L-Citrulline supplement.

L-Citrulline may interact with antihypertensive medications, nitrate drugs, and phosphodiesterase-5 inhibitors (e.g., Viagra(R)). If you are taking any of these medications, or if you are pregnant or lactating, consult your healthcare practitioner before using this product.

See for yourself

L-Citrulline 750 mg by Protocol For Life Balance label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

What’s inside

The Ingredients in L-Citrulline 750 mg by Protocol For Life Balance

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size4 Capsule(s) Dosage formCapsule Servings per container45 Amounts shown are per serving.

L-Citrulline

Interacts with
178 drugs
3 g per serving

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. I...

L-Citrulline monograph & interactions

Other (inactive) ingredients: Gelatin, Calcium Carbonate, Magnesium Oxide, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Citrulline 750 mg by Protocol For Life Balance Drug Interactions

Want to check YOUR meds against L-Citrulline 750 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

Go to the checker
178Drugs
178 Moderate

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Citrulline 750 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

L-Citrulline2 drug types · 178 drugs

Antihypertensive Drugs

Theoretically, concomitant use of L-citrulline with antihypertensive drugs might have additive effects and increase the chance of hypotension.
L-citrulline is converted to L-arginine, which can increase nitric oxide and cause vasodilation. However, a meta-analysis of 5 small clinical studies suggests that taking L-citrulline 3-6 grams daily for 1-8 weeks does not lower blood pressure when compared with control.

Likelihood Possible Evidence B
Phosphodiesterase-5 Inhibitors

Theoretically, concurrent use of phosphodiesterase-5 (PDE-5) inhibitors and L-citrulline might result in additive vasodilation.
L-citrulline is converted to L-arginine, which can increase nitric oxide and cause vasodilation. Theoretically, taking L-arginine with PDE-5 inhibitors might have additive vasodilatory and hypotensive effects. However, in studies evaluating the combined use of L-arginine and sildenafil for erectile dysfunction, hypotension was not reported.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for L-Citrulline 750 mg, from the product label.

Protocol For Life Balance

See all Protocol For Life Balance products
Name
Protocol For Life Balance(TM)
Street Address
395 S. Glen Ellyn Rd
City
Bloomingdale
State
IL
ZipCode
60108
Pharmacist Counseling Corner

L-Citrulline 750 mg by Protocol For Life Balance: Common Questions

Does L-Citrulline 750 mg by Protocol For Life Balance interact with any medications?
Yes. Based on its ingredients, L-Citrulline 750 mg has a known interaction with 178 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Citrulline 750 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will L-citrulline help me build muscle or improve my workouts?
L-citrulline is rated possibly effective for athletic performance, which means some evidence suggests it may help, but the research isn't definitive. It's not rated as effective for sarcopenia (age-related muscle loss). For specific goals, talk with your doctor or a sports nutritionist.
What side effects should I watch for?
The most common are gastrointestinal—heartburn, stomach discomfort, and general GI upset. These tend to be mild. A small number of people with lung issues reported cough. Stop and contact your pharmacist or doctor if side effects bother you or don't go away.
Is it safe to take L-citrulline if I'm pregnant or breastfeeding?
No. There isn't enough safety data to recommend it during pregnancy, so avoid it if you're pregnant. Safety while breastfeeding is also unknown, so skip it if you're nursing. If you're planning pregnancy or are already nursing and have other questions, talk with your doctor or pharmacist.
Can I take this with my blood pressure medication?
Don't assume yes. L-citrulline can lower blood pressure and may intensify the effect of your medication, risking dangerously low blood pressure. Check your exact medication against the tool on this page, and talk with your doctor or pharmacist before starting.
What is L-citrulline and what does it do in my body?
L-citrulline is an amino acid. Your body converts it to another amino acid called L-arginine, which helps widen blood vessels and improve blood flow by increasing a molecule called nitric oxide.
How long has this supplement been studied?
L-citrulline has been studied for athletic performance and some other uses, but long-term safety—what happens if you take it for years—hasn't been fully explored yet.

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

Not sure if L-Citrulline 750 mg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

L-Citrulline 750 mg label
Sources

Sources & How We Checked

L-Citrulline 750 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 8 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

L-citrulline 8 references
  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

See these in context on the L-citrulline monograph →

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

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