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Dietary supplement

L-Citrulline Ingredients & Drug Interactions

by Allergy Research Group

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

L-Citrulline is a dietary supplement by Allergy Research Group 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 by Allergy Research Group

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 powder contains one active ingredient: L-citrulline, an amino acid your body converts to arginine, which helps produce nitric oxide — a chemical that relaxes blood vessels and improves blood flow. There are no other inactive ingredients listed.

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: detoxification and vasodilation.
  • We looked for evidence on: Cardiovascular disease (CVD), Erectile dysfunction (ED), Heart failure, Pulmonary hypertension, blood flow, circulation — and 1 related terms.
  • The closest evidence on file: L-citrulline is rated "Insufficient Reliable Evidence To Rate" for Cardiovascular disease (CVD) (Natural Medicines).
  • Also on file: L-citrulline is rated "Insufficient Reliable Evidence To Rate" for Heart failure, Erectile dysfunction (ED), Hypertension, Pulmonary hypertension.

L-citrulline is possibly effective for athletic performance. For other uses in the product facts — heart failure, cardiovascular disease, diabetes, Reye syndrome, and sarcopenia — either there isn't enough reliable evidence to rate it, or the evidence suggests it's possibly ineffective (sarcopenia).

If athletic performance is what you're after, the data supports a possible benefit; for other conditions, we don't have solid evidence one way or the other.

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, though long-term safety hasn't been fully studied. The most common side effects are stomach upset, heartburn, and gastrointestinal discomfort.

A small number of people with pulmonary hypertension reported cough when taking it. Don't use this supplement during pregnancy or while breastfeeding — there isn't enough safety data in either situation.

If you're pregnant, nursing, or planning to become pregnant, talk with your doctor or pharmacist before taking it.

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.

Check before starting if you take any blood pressure-lowering medication (antihypertensives) or erectile dysfunction drugs like sildenafil or tadalafil — both are Moderate-severity interactions. L-citrulline's blood-vessel-widening effect can add to theirs and lower your pressure too much.

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 may help with athletic performance if that's your goal, but it's not established for heart health or muscle loss. If you take blood pressure medication or erectile dysfunction drugs, check with your doctor or pharmacist first — this supplement can add to their effects.

It's generally tolerated well, but steer clear if you're pregnant or breastfeeding.

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 Aug 23, 2020.

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, straight from the product label.

Brand Allergy Research Group
Barcode (UPC) 713947747609
Net contents 100 Gram(s); 3.5 Oz(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 233444
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Children 4 or More Years of Age, Adult (18 - 50 Years)
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 by Allergy Research Group, 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:
3 Gram(s)
Maximum serving Sizes:
3 Gram(s)
Servings per container
33
UPC/BARCODE
713947747609
IngredientAmount% DV
L-Citrulline3 Gram(s)--

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.
Formula

L-citrulline, a free form amino acid.

Formulation

High purity, well tolerated.

Detoxification and vasodilation

Hypoallergenic

Suggested/Recommended/Usage/Directions

Suggested use As a dietary supplement, 1 teaspoon two times daily, or as directed by a healthcare practitioner.

Precautions

Contraindicated for individuals with kidney abnormalities, a hypersensitivity to L-citrulline, or for children under 12 years of age.

Contraindicated for individuals with kidney abnormalities, a hypersensitivity to L-citrulline, or for children under 12 years of age.

Storage

Keep in a cool, dry place, tightly capped.

Brand IP Statement(s)

Protected by United States Patent Nos. 5,874,471 and 6,028,107

FDA Statement of Identity

Dietary Supplement

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

See for yourself

L-Citrulline by Allergy Research Group label

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

What’s inside

The Ingredients in L-Citrulline by Allergy Research Group

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

Serving size3 Gram(s) Dosage formPowder Servings per container33 Amounts shown are per serving.

L-Citrulline

Interacts with
178 drugs
3 Gram(s) 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
Interaction report

L-Citrulline by Allergy Research Group Drug Interactions

Want to check YOUR meds against L-Citrulline?

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 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, from the product label.

Allergy Research Group

See all Allergy Research Group products
Name
Allergy Research Group
City
South Salt Lake
State
UT
ZipCode
84115
Phone Number
800-545-9960
Web Address
www.allergyresearchgroup.com
Pharmacist Counseling Corner

L-Citrulline by Allergy Research Group: Common Questions

Does L-Citrulline by Allergy Research Group interact with any medications?
Yes. Based on its ingredients, L-Citrulline 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 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 this help me build muscle or get stronger?
L-citrulline is possibly effective for athletic performance, so it may help with exercise capacity and endurance. The evidence is stronger for that than for muscle growth (sarcopenia), where it's possibly ineffective.
What's the most common side effect?
Stomach upset, heartburn, and general gastrointestinal discomfort are the most common. Most people tolerate it well, though long-term safety studies are limited.
Can I take this if I'm pregnant?
No — there isn't enough safety data. Avoid it during pregnancy and while breastfeeding. Talk with your doctor or pharmacist about what's safe for you.
Why do I need to check my blood pressure meds with this?
L-citrulline widens your blood vessels to improve blood flow, just like blood pressure medication does. Taking both together could lower your pressure too much. Your doctor or pharmacist can tell you if it's safe for your specific dose and situation.
Is this ingredient natural?
L-citrulline is an amino acid found in foods like watermelon. This is a supplemental form, but the ingredient itself exists in nature.

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

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

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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 label
Sources

Sources & How We Checked

L-Citrulline'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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