Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Free Form L-Citrulline Unflavored Ingredients & Drug Interactions

by Muscle Feast

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

Free Form L-Citrulline Unflavored is a dietary supplement by Muscle Feast 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 Free Form L-Citrulline Unflavored by Muscle Feast

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 L-arginine. There are no inactive ingredients 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: muscle recovery, blood flow and vascularity.
  • We looked for evidence on: Athletic performance, Muscle strength, Erectile dysfunction (ED), Hypertension, exercise endurance, nitric oxide production.
  • The strongest evidence on file: L-citrulline is rated "Possibly Effective" for Athletic performance (Natural Medicines).
  • Also on file: L-citrulline is rated "Insufficient Reliable Evidence To Rate" for Erectile dysfunction (ED), Postoperative pulmonary hypertension, Muscle strength, Pulmonary hypertension.

The data shows L-citrulline is possibly effective for athletic performance. For sarcopenia (age-related muscle loss), it's rated possibly ineffective.

For cardiovascular disease, heart failure, Reye syndrome, and diabetes, there isn't enough reliable evidence in our data to rate how well it works.

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 to recommend this supplement during pregnancy or while breastfeeding — talk with your doctor or pharmacist about whether it's right for you if you're pregnant or nursing.

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 your blood pressure medications (antihypertensives) and erectile dysfunction drugs (PDE-5 inhibitors) before taking this product — both can interact with L-citrulline at a Moderate severity level. Your doctor or pharmacist can advise whether the combination is safe for you.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

If you're looking to support athletic performance, L-citrulline may be worth considering — but only after you've checked it against your own medications, especially blood pressure drugs and erectile dysfunction medications. Long-term safety data is limited.

Talk it over with your doctor or pharmacist before you start, particularly if you're pregnant, breastfeeding, or taking any prescription medications.

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 Feb 23, 2022.

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 Free Form L-Citrulline Unflavored, straight from the product label.

Brand Muscle Feast
Net contents 7 Ounce(s); 200 Gram(s)
Market status On market
Date entered into DSLD Feb 23, 2022
DSLD ID 259980
Product type Amino Acid/protein
Supplement form Powder
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten 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 Free Form L-Citrulline Unflavored by Muscle Feast, 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
66
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

Muscle Feast Citrulline has been shown to relax blood vessels, improve blood flow and raise overall nitric oxide levels. Many body builders take citrulline with their pre and post workout drinks to help improve recovery, increase vascularity and improve muscle pumps throughout the day and following a training session.

Certified Gluten Free GFCO.org (Gluten-Free Certification Organization)

Non-GMO

Certified Vegan AVA American Vegetarian Association

Formula

Many body builders take citrulline with their pre and post workout drinks to help improve recovery, increase vascularity and improve muscle pumps throughout the day and following a training session.

Free form L-Citrulline 3000 mg per serving / pharmaceutical grade

Suggested/Recommended/Usage/Directions

Suggested use: As an adult dietary supplement, take one serving (3 g) in 6-8 ounces of a water or a flavored beverage, 2-3 times per day or as needed. Mix 1 level (3 g) scoop with 8 oz. water or beverage of choice.

Seals/Symbols

Made in an FDA Registered Facility GMP Good Manufacturing Practice Certified Gluten Free GFCO.org (Gluten-Free Certification Organization) Certified Vegan AVA American Vegetarian Association

General Statements

SDVOSB Service Disabled Veteran Owned Small Business

Ohio family owned business

FDA Statement of Identity

Dietary Supplement

Storage

Keep tightly closed in a cool, dry place away from sunlight.

Precautions

Keep out of reach of children.

Do not exceed the recommended dose. Consult your physician before using this product.

Do not use this product if you are pregnant or nursing. Do not use this product if you are taking any prescription medication.

Do not use this product if you are under the age of 18.

Warning: This product is manufactured in a GMP compliant plant that processes milk.

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

Free Form L-Citrulline Unflavored by Muscle Feast label

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

What’s inside

The Ingredients in Free Form L-Citrulline Unflavored by Muscle Feast

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 container66 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

Free Form L-Citrulline Unflavored by Muscle Feast Drug Interactions

Want to check YOUR meds against Free Form 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 Free Form 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 Free Form L-Citrulline Unflavored, from the product label.

Muscle Feast

See all Muscle Feast products
Name
Muscle Feast
Street Address
1320 Boston Road
City
Nashport
State
OH
ZipCode
43830
Phone Number
(888) 734-3634
Web Address
www.musclefeast.com
Pharmacist Counseling Corner

Free Form L-Citrulline Unflavored by Muscle Feast: Common Questions

Does Free Form L-Citrulline Unflavored by Muscle Feast interact with any medications?
Yes. Based on its ingredients, Free Form 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?
Free Form 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.
What does L-citrulline actually do in my body?
L-citrulline is an amino acid your body converts into another amino acid called L-arginine. That conversion increases nitric oxide in your blood vessels, which causes them to relax and dilate — essentially widening the vessels. That's why it's theoretically helpful for athletic performance and blood flow.
Can I take this if I'm on blood pressure medication?
L-citrulline can add to the blood-pressure-lowering effect of these drugs, raising the risk of your blood pressure dropping too low. Before taking this product, check with your doctor or pharmacist — they know your specific medications and blood pressure and can tell you whether it's safe for you.
What are the common side effects?
Most people tolerate it well. The most common side effects are gastrointestinal discomfort and heartburn. A small number of people with pulmonary hypertension reported cough.
Is this safe to use while pregnant or breastfeeding?
There isn't enough safety data for either. If you're pregnant or breastfeeding, talk with your doctor or pharmacist — they can help you decide whether this supplement is appropriate for your situation.
Does this product have fillers or other additives?
No — it's just the L-citrulline powder with no other inactive ingredients listed.
Has long-term safety been studied?
Not fully. While L-citrulline is generally well tolerated in the short term, long-term safety data is limited, so the facts we hold don't cover extended use in detail.

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

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

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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.

Free Form L-Citrulline Unflavored label
Go deeper

The Full Monographs Behind Free Form 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

Free Form 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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