Enhanced cardiovascular health
Supports healthy blood pressure and circulation
L-Arginine
Semi-essential amino acid crucial for nitric oxide production, cardiovascular health, and immune function
Scientific nameL-Arginine
FormulaC6H14N4O2
Molecular weight174.2 g/mol
CAS74-79-3
70
absorption score
7
safety / 10
25
USD per month
5
documented interactions
Check it against something
L-Arginine with:
- Amylase
- Ashwagandha
- Avocado Oil
- BCAA (Branched-Chain Amino Acids)
- Beetroot Powder
- Beta-Alanine
- Bifidobacterium lactis
- Bifidobacterium longum
- Bovine Collagen
- Caffeine
- Calcium
- Calcium Bone Formula
- Calcium Carbonate
- Casein Protein
- Chicken Collagen
- Choline (Bitartrate)
- Chondroitin Sulfate
- Citrulline Malate
- Coconut Oil
- Collagen Peptides
- Comprehensive Immune Support Complex
- Comprehensive Multivitamin-Mineral Complex
- Creatine HCL
- Creatine Monohydrate
- D-Mannose
- DHA
- Electrolyte Blend
- EPA
- Fish Oil (EPA/DHA)
- Folate (5-MTHF)
- Ginger
- Iron Fumarate
- Iron Sulfate
- Joint Mobility Formula
- Keratin
- Krill Oil
- L-Carnitine
- L-Citrulline
- Lactase
- Lactobacillus acidophilus
- Lactobacillus rhamnosus
- Lipase
- Magnesium Citrate
- Magnesium Glycinate
- Magnesium Oxide
- Marine Collagen
- Melatonin
- Modafinil
- Olive Oil Extract
- Omega-3 + Curcumin + Vitamin D Triple Anti-Inflammatory Formula
- Papain
- Protease
- Saccharomyces boulardii
- Turmeric
- Vitamin B12 (Cyanocobalamin)
- Vitamin B12 (Methylcobalamin)
- Vitamin C (Ascorbic Acid)
- Vitamin C (Sodium Ascorbate)
- Vitamin D3
- Whey Protein
- Zinc Gluconate
Nothing found
82
out of 100
Works better together
Compatible. Timing differs, so follow each supplement's own window.
What it does
mechanism and evidence for each claimImproved athletic performance
Enhances exercise capacity and muscle blood flow
Enhanced immune system function
Supports immune cell function and wound healing
Accelerated wound healing
Supports faster tissue repair and recovery
Improved erectile function
May support male sexual health and function
Others take these for the same thing
Same goal, different mechanism — check any of them against this one
Coenzyme Q10 (CoQ10)
Heart health & cellular energy
100-200mg
A
10%
Fish Oil (EPA/DHA)
Heart & brain health
1-2g EPA/DHA
A
85%
Psyllium Husk
Digestive health & cholesterol support
5-15g
A
95%
Calcium Citrate
Superior absorption bone & heart health
500-1200 mg
A
45%
Taurine
Cardiovascular & exercise support
1-3g
A
95%
L-Citrulline
Athletic performance & circulation
3-8g
A
95%
Every pair we checked
12 combinations scored by the engine
L-Arginine + L-Lysine
Lysine and arginine compete for absorption and uptake
Needs attention
10
L-Arginine + Caffeine
No documented interaction either way
No known interaction
70
L-Arginine + Creatine Monohydrate
No documented interaction either way
No known interaction
70
L-Arginine + Calcium Carbonate
No documented interaction either way
No known interaction
70
L-Arginine + Whey Protein
No documented interaction either way
No known interaction
70
L-Arginine + Lactase
No documented interaction either way
No known interaction
70
L-Arginine + Bovine Collagen
No documented interaction either way
No known interaction
70
L-Arginine + DHA
No documented interaction either way
No known interaction
70
L-Arginine + Turmeric
No documented interaction either way
No known interaction
70
L-Arginine + Vitamin D3
Protects nitric oxide from oxidation
Works better together
78
L-Arginine + L-Citrulline
More effective precursor to arginine and nitric oxide
Works better together
82
L-Arginine + Folate (5-MTHF)
Protects nitric oxide from oxidation
Works better together
86
Dosage
Daily3-6g
Cardiovascular3-6g daily (divided)
Athletic performance3-6g pre-exercise
Wound healing5-10g daily
Upper limit20g daily (medical supervision)
Before you take it
VeganYes
When to expect it
First Effects1-2 weeks for cardiovascular and performance benefits
Peak Benefits4-8 weeks for sustained circulation and immune benefits
Deficiency DevelopmentWeeks during stress, illness, or inadequate intake
Toxicity OnsetRare, mainly digestive and blood pressure issues
How to measure it
MarkerPlasma arginine, nitric oxide metabolites, or citrulline
OptimalArginine: 50-150 μmol/L
Deficient below<40 μmol/L
FrequencyOnly if monitoring cardiovascular or immune function
What people actually reported to the FDA
CAERS, 85 reports naming it as the suspectMost reported effects
Named as the suspect
85 reports
of 108 that mention it at all
Serious outcome
83%
hospitalisation, emergency room or worse
Other Serious or Important Medical Event56
Visited Emergency Room23
Hospitalization21
Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →
What actually reaches you
The label counts the carrier, your body does not
Absorption
High 70 of 100 · absorbs well relative to other forms
Delivered daily
3150 mg
Cost per 100 mg delivered
$0.03 comparative — uses the absorption score, not a measured percentage
Works better with
+
Citrulline
More effective precursor to arginine and nitric oxide
Converts to arginine with better absorption · level A
+
Vitamin C
Protects nitric oxide from oxidation
Antioxidant protection preserves NO function · level B
+
Folate
Supports nitric oxide synthase function
Required cofactor for NO production · level BWhat not to take with L-Arginine
!
Lysine
Lysine and arginine compete for absorption and uptake
Competition for transporters and cellular uptake · major significance
!
Other Basic Amino Acids
Competition with ornithine and histidine
Shared transport mechanisms · moderate significanceMedication interactions
Discuss these with a pharmacist before combiningMay enhance blood pressure lowering effects
What to do: Monitor blood pressure, may need dose adjustments
May enhance effects and risk of low blood pressure
What to do: Use caution, monitor for hypotension
May enhance anticoagulant effects
What to do: Monitor bleeding parameters
Available forms
L-Arginine (Free Form): Cardiovascular support, Athletic performance, Immune function, Well-researched
Food sources
Turkey and poultry
1.8-2.5g per 100g · 70
Pork and red meat
1.5-2.0g per 100g · 70
Fish and seafood
1.2-1.8g per 100g · 70
Nuts and seeds
0.8-2.5g per 100g · 60
Too little
- Poor wound healing and tissue repair
- Impaired immune function and frequent infections
- Poor exercise performance and recovery
- Hair loss and poor hair quality
- Muscle weakness and fatigue
- Poor circulation and cold extremities
- Delayed growth in children
Too much
- Generally well-tolerated:
- Gastrointestinal upset and diarrhea
- Potential blood pressure drops
- Possible herpes virus activation
- Kidney stress with very high doses
Who benefits most
cardiovascular-health
Supports healthy blood pressure and circulation
3-6g daily (divided doses)
athletic-performance
Enhances exercise capacity and muscle blood flow
3-6g before exercise
wound-healing-recovery
Supports faster tissue repair and immune function
5-10g daily
immune-support
Essential for optimal immune system function
3-6g daily
erectile-dysfunction
May support male sexual health through improved blood flow
3-5g dailyWhere to buy it
Look for L-Arginine at 3-6g per serving. The form that matters here is L-Arginine (Free Form).
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How it works
- Converted to nitric oxide via nitric oxide synthase enzymes
- Nitric oxide causes vasodilation and improved blood flow
- Essential substrate for T-cell proliferation and immune function
- Required for collagen synthesis and wound healing
- Important for creatine synthesis and energy metabolism
- Essential component of the urea cycle for ammonia detoxification
Key findings
what the evidence supports- Effective for cardiovascular health and blood pressure support
- Important for immune function and wound healing
- May improve athletic performance through enhanced blood flow
- Competes with lysine - balance is important
Sources: NIH Examine.com · data reviewed 2026-08-02
Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →
Common questions
What are the benefits of L-Arginine?
Documented effects: Enhanced cardiovascular health; Improved athletic performance; Enhanced immune system function; Accelerated wound healing. Supports healthy blood pressure and circulation
How much L-Arginine should you take per day?
The common daily range is 3-6g. By goal — cardiovascular: 3-6g daily (divided); athletic performance: 3-6g pre-exercise; wound healing: 5-10g daily; upper limit: 20g daily (medical supervision).
When is the best time to take L-Arginine?
Empty stomach. First effects are typically reported within 1-2 weeks for cardiovascular and performance benefits.
What are the side effects of L-Arginine?
At excessive doses: Generally well-tolerated:, Gastrointestinal upset and diarrhea, Potential blood pressure drops, Possible herpes virus activation, Kidney stress with very high doses. Safety rating at normal doses is 7 out of 10.
What should you not take with L-Arginine?
Separate it from Lysine, Other Basic Amino Acids by two to four hours. Lysine and arginine compete for absorption and uptake
Does L-Arginine interact with medications?
Documented interactions with blood-pressure-medications, viagra-pde5-inhibitors, blood-thinners. Discuss these with a pharmacist before combining.
How do you know if you need L-Arginine?
The marker is Plasma arginine, nitric oxide metabolites, or citrulline, optimal range Arginine: 50-150 μmol/L. Common deficiency signs: Poor wound healing and tissue repair, Impaired immune function and frequent infections, Poor exercise performance and recovery, Hair loss and poor hair quality.