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Dietary supplement

L-Citrulline Ingredients & Drug Interactions

by Hard Rhino

Powder Category: Amino Acid/protein
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.

Hard Rhino L-Citrulline is a single-ingredient powder: L-Citrulline, an amino acid your body converts to L-arginine. There are no other active ingredients.

The product contains no inactive fillers or excipients listed.

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 supports its use in that context. For sarcopenia (age-related muscle loss), the evidence suggests it's possibly ineffective.

For cardiovascular disease, heart failure, Reye syndrome, and diabetes, we don't have enough reliable evidence in our data to rate whether it works 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 with pulmonary hypertension reported cough.

There isn't enough safety data for pregnancy, so it's best to avoid it during pregnancy. Safety while breastfeeding is unknown — avoid supplemental use unless your doctor advises otherwise.

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 start Hard Rhino L-Citrulline, check with your doctor or pharmacist if you take blood pressure medications or erectile dysfunction drugs like sildenafil (Viagra) or tadalafil (Cialis) — both can have Moderate interactions and may cause a bigger drop in blood pressure than intended when combined with this product.

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 help with athletic performance, but if you take blood pressure medication or erectile dysfunction drugs, you'll want to check with your doctor or pharmacist first. It's generally well tolerated in people without heart conditions, though stomach upset can happen.

Pregnant or breastfeeding? Skip it unless your healthcare provider says otherwise.

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 Mar 24, 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) 798711500277
Net contents 5 kg; 11 lbs
Market status On market
Date entered into DSLD Mar 24, 2017
DSLD ID 72071
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), No Allergies, 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
1666
UPC/BARCODE
798711500277
IngredientAmount% DV
L-Citrulline3 Gram(s)--

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

-Non-GMO -Gluten free -Allergen free

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

General Statements

Bulk pail - Best value - Scoop inside - 1666 servings

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 3 rounded scoop (~3 grams) twice daily with 8-12 ounces of water or suitable beverage. Taken 30 minutes prior to workout and again immediately after for maximum results.

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 seal is broken.

FDA Statement of Identity

Dietary Supplement

Storage

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

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 container1666 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

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
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.
Does L-Citrulline really help with workouts?
The evidence says it's possibly effective for athletic performance — so there's reason to think it may help, but the research isn't huge. Talk to your trainer or doctor about whether it makes sense for your goals.
What's L-Citrulline doing in my body?
Your body converts it to L-arginine, which increases nitric oxide — a signaling molecule that relaxes your blood vessels and improves blood flow. That's why it may help with athletic performance and why it can interact with blood pressure and ED medications.
Will L-Citrulline give me stomach problems?
It's generally well tolerated, but gastrointestinal discomfort and heartburn are the most common side effects people report. Most folks don't have issues, but if your stomach is sensitive, start low and see how you feel.
Can I take this while pregnant or breastfeeding?
There isn't enough safety data for pregnancy — it's best to avoid it. Safety while breastfeeding is also unknown, so skip supplemental use unless your doctor says it's okay. Talk to your OB or midwife before starting.
Is this just L-Citrulline, or are there fillers?
This is a straightforward single-ingredient powder — just L-Citrulline with no other active or inactive ingredients listed.

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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