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Dietary supplement

L-Citrulline Unflavored Ingredients & Drug Interactions

by Staunch Labs

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

L-Citrulline Unflavored is a dietary supplement by Staunch Labs 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 Unflavored by Staunch Labs

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 uses to make another amino acid called L-arginine. L-arginine plays a role in blood vessel function and circulation.

The powder form means there are no fillers or binders — just the L-citrulline itself.

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 function during exercise. For sarcopenia (age-related muscle loss), the evidence suggests it's possibly ineffective.

For heart failure, cardiovascular disease, diabetes, and Reye syndrome, there isn't enough reliable evidence in our data 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 stomach discomfort, heartburn, and gastrointestinal discomfort.

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

Similarly, safety while breastfeeding is unknown, so avoid it if you're nursing. Talk with your doctor or pharmacist about whether it's right for you in these situations.

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 taking L-Citrulline Unflavored, double-check with your doctor or pharmacist if you take blood pressure medications (antihypertensive drugs) or erectile dysfunction medications (phosphodiesterase-5 inhibitors) — both have Moderate interactions that could amplify blood-pressure-lowering effects. These are the main medication types to watch for 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 it's worth considering if you take blood pressure medications or erectile dysfunction drugs — it could intensify their blood-pressure-lowering effects. The supplement is generally well tolerated, though some people experience stomach discomfort.

Check your exact medications with your doctor or pharmacist before you start, especially if you're on blood pressure or ED medication.

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 Sep 25, 2023.

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 Unflavored, straight from the product label.

Brand Staunch Labs
Barcode (UPC) 858043008138
Net contents 500 Gram(s); 1.1 lb(s)
Market status On market
Date entered into DSLD Sep 25, 2023
DSLD ID 297705
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) 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 Unflavored by Staunch Labs, 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:
5 Gram(s)
Maximum serving Sizes:
5 Gram(s)
Servings per container
100
UPC/BARCODE
858043008138
IngredientAmount% DV
L-Citrulline5 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.
Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, mix 1 scoop daily with 6-10 ounces of water.

Precautions

Warning: This product is only intended to be consumed by healthy individuals 18 years of age or older.

Consult your physician prior to use if you are pregnant or nursing.

Do not exceed directed use. Improper use will not improve results and is not advised.

Keep out of reach of children.

Do not use if safety seal is broken.

Storage

Storage: Product is filled by weight not volume, some settling may occur. To keep product fresh and prevent clumping, store tightly-closed in a cool, dry place.

FDA Disclaimer Statement

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

Brand IP Statement(s)

Copyright 2019 Staunch Nutrition

Formulation

Pure L-Citrulline Powder

Formula

L-Citrulline 5 g Per Serving / 500 g Per Container / 100 servings

FDA Statement of Identity

Dietary Supplement

See for yourself

L-Citrulline Unflavored by Staunch Labs label

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

What’s inside

The Ingredients in L-Citrulline Unflavored by Staunch Labs

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

Serving size5 Gram(s) Dosage formPowder Servings per container100 Amounts shown are per serving.

L-Citrulline

Interacts with
178 drugs
5 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 Unflavored by Staunch Labs Drug Interactions

Want to check YOUR meds against L-Citrulline Unflavored?

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 Unflavored 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 Unflavored, from the product label.

Staunch Labs

See all Staunch Labs products
Name
Staunch Nutrition
Street Address
351 E 1750 N
City
Vineyard
State
UT
ZipCode
84059
Pharmacist Counseling Corner

L-Citrulline Unflavored by Staunch Labs: Common Questions

Does L-Citrulline Unflavored by Staunch Labs interact with any medications?
Yes. Based on its ingredients, L-Citrulline Unflavored 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 Unflavored 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.
Can I take L-citrulline if I'm pregnant or breastfeeding?
There isn't enough safety data to know either way. The safety data advises against supplements during pregnancy and recommends avoiding them while breastfeeding. Talk with your doctor or pharmacist for personalized advice.
What are the most common side effects?
Stomach discomfort, heartburn, and gastrointestinal discomfort are the most commonly reported. Overall, L-citrulline is generally well tolerated in healthy adults.
Does L-citrulline actually improve athletic performance?
It's possibly effective for athletic performance — some evidence supports it may help with endurance and muscle function during exercise, though the evidence isn't definitive.
What is L-citrulline supposed to do?
L-citrulline is an amino acid that your body converts to another amino acid called L-arginine, which helps with blood vessel function and circulation.
Does this powder have any fillers or other ingredients?
No — it's just L-citrulline powder with no inactive ingredients added.

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

Not sure if L-Citrulline Unflavored 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 Unflavored label
Go deeper

The Full Monographs Behind L-Citrulline Unflavored’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Sources

Sources & How We Checked

L-Citrulline Unflavored'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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