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Dietary supplement

L-Citrulline Ingredients & Drug Interactions

by Hard Rhino

Powder Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Citrulline is a dietary supplement by Hard Rhino 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 Hard Rhino

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: L-Citrulline, an amino acid your body converts to another amino acid called L-arginine. That conversion triggers the release of nitric oxide, a signaling molecule that helps blood vessels relax and improve blood flow.

There are no inactive ingredients listed for this powder.

Does it work?

Moderate evidence
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

This product doesn't appear to be marketed for a specific use, so we graded L-citrulline's overall clinical evidence instead.

Moderate

Some clinical evidence supports L-citrulline for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Athletic performance — rated "Possibly Effective" (Natural Medicines).

L-Citrulline is possibly effective for athletic performance—some evidence suggests it may help with endurance and muscle fatigue during exercise. For sarcopenia (age-related muscle loss), the evidence suggests it's possibly ineffective.

The data we hold shows insufficient evidence to rate it for cardiovascular disease, heart failure, Reye syndrome, or diabetes, which means we don't have reliable studies to say whether it helps or doesn't.

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 gastrointestinal discomfort and heartburn.

A small number of people taking it have reported cough, and stomach discomfort has been noted in some users. There isn't enough safety data to use this supplement during pregnancy, and safety while breastfeeding is unknown—talk with your doctor or pharmacist if you're pregnant, trying to conceive, or nursing 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.

If you take blood pressure medications or phosphodiesterase-5 inhibitors (Viagra, Cialis, or similar), double-check with your pharmacist before taking L-Citrulline. Both interactions are rated Moderate and could cause your blood pressure to drop too low when combined.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

L-Citrulline may be worth considering if you're interested in athletic performance support, but it's not proven for most other uses. If you take blood pressure medications or PDE-5 inhibitors, check your exact drugs with your pharmacist before starting—the combination could lower your blood pressure unexpectedly.

Talk with your own doctor or pharmacist about whether it fits your situation.

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 Apr 25, 2017.

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 Hard Rhino
Barcode (UPC) 818132892819
Net contents 125 Gram(s); 4.4 Oz(s)
Market status On market
Date entered into DSLD Apr 25, 2017
DSLD ID 72550
Product type Non-nutrient/non-botanical
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy 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 by Hard Rhino, 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
41
UPC/BARCODE
818132892819
IngredientAmount% DV
L-Citrulline3000 mg--

Other ingredients: None

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.
Formulation

No added fillers

Allergens: This product contains no soy, dairy, dairy byproducts, eggs, shellfish, wheat, gluten, tree nuts, or sesame seeds.

This is a non-GMO ingredient.

General Statements

Only pure ingredients

Pure powder

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 3000 mg (rounded ~1tsp) twice daily with 16 ounces of water or suitable beverage. Taken 30 minutes prior to workout and again immediately after for maximum results.

1 Carefully measure out suggested serving size using a microscale. 2 Add to preferred beverage. 3 Mix well. 4 Drink within 10-15 minutes. How to use

Storage: Store in a cool, dry place. Re-seal zipper immediately after use to preserve freshness.

FDA Disclaimer Statement

These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any diseases.

Precautions

Warning: Keep out of the reach of children. Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions and/or taking prescription drug(s) or OTC medication(s).

Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions and/or taking prescription drug(s) or OTC medication(s).

Always consult with a qualified health physician before taking any new dietary supplement.

Do not use or consume if pressure seal is broken.

Do not use or consume if seal is broken.

Seals/Symbols

Lab tested for purity and quality

Packaged in USA

FDA Statement of Identity

Dietary Supplement

See for yourself

L-Citrulline by Hard Rhino label

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

What’s inside

The Ingredients in L-Citrulline by Hard Rhino

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 container41 Amounts shown are per serving.

L-Citrulline

Interacts with
178 drugs
3000 mg 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: None. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Citrulline by Hard Rhino 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.

Hard Rhino

See all Hard Rhino products
Name
Guardian Wholesale
Street Address
1607 West Whispering Wind Drive
City
Phoenix
State
AZ
ZipCode
85085
Phone Number
(866) 961-8378
Web Address
HardRhino.com
Pharmacist Counseling Corner

L-Citrulline by Hard Rhino: Common Questions

Does L-Citrulline by Hard Rhino 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.
What does L-Citrulline actually do in my body?
Your body converts L-Citrulline to L-arginine, which triggers the release of nitric oxide. That molecule tells your blood vessels to relax and widen, improving blood flow throughout your body.
Will it help my athletic performance?
L-Citrulline is possibly effective for athletic performance based on available evidence. Some studies suggest it may help with endurance and muscle fatigue during exercise, though results vary.
What side effects should I watch for?
Gastrointestinal discomfort and heartburn are the most common. A small number of people have reported cough or stomach discomfort. It's generally well tolerated, but long-term safety hasn't been fully studied.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data to recommend L-Citrulline during pregnancy, and safety while breastfeeding is unknown. Talk with your doctor or pharmacist before using it if you're pregnant, trying to conceive, or nursing.
Does it work for heart disease or diabetes?
We don't have reliable evidence to say whether L-Citrulline helps or doesn't help with cardiovascular disease, heart failure, or diabetes. The data is insufficient to rate it for these uses.

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

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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 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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