Citrulline

L-Citrulline, or simply just citrulline, is a nonessential amino acid. It is efficiently turned into L-arginine in the kidneys after supplementation, which makes it a good choice for increasing nitric oxide synthesis in the body.

Quick Answer

What it is

L-Citrulline, or simply just citrulline, is a nonessential amino acid. It is efficiently turned into L-arginine in the kidneys after supplementation, which makes it a good choice for increasing nitric oxide synthesis in the body.

Key findings

  • Grade B: Arterial Stiffness
  • Grade B: Blood Pressure (Heart Failure)
  • Grade C: Blood Flow (Muscle Recovery)

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts: Citrulline

Quick Facts: Citrulline

  • Best Evidence:Grade B
  • Conditions Studied:20
  • Research Outcomes:169
  • Grade B Findings:2
  • Key Effect:Heart Failure
Outcomes by grade:
A0
B2
C8
D11
20 conditions · 169 outcomes

Detailed Outcomes

Grade:
Effect:
Size:
Sort:
|
B
Arterial Stiffness
Small Improvement
smallImproves
?
Blood Pressure
Improves
?
Blood Flow
Improves
?
Heart Rate
Improves
B
Blood Pressure
Small Improvement
smallImproves
?
Right Ventricular Ejection Fraction
2 studies
Improves
?
Exercise Tolerance
1 study
Improves
?
Left Ventricular Ejection Fraction
1 study
Improves
C
Arterial Stiffness
Small Improvement
smallImproves
?
Blood Pressure
Improves
?
Blood Flow
Improves
?
Blood glucose
1 study
Improves
?
Body Fat
Improves
?
C-Reactive Protein (CRP)
1 study
Improves
?
Heart Rate Variability
Improves
?
High-density lipoprotein (HDL)
Improves
?
Low-density lipoprotein (LDL)
1 study
Improves
?
Nitric Oxide
1 study
Improves
?
Plasma Arginine
Improves
?
Plasma Nitrate
1 study
Improves
?
Total cholesterol
1 study
Improves
C
Blood Flow
Small Increase
smallImproves
?
Blood Lactate (Exercise)
Worsens
?
Muscle Soreness
Improves
?
Rating of Perceived Exertion
Improves
?
Muscular Endurance
Improves
?
Creatine Kinase
1 study
Worsens
?
Lactate Threshold
1 study
Improves
C
Asthma Symptoms
Small Improvement
smallImproves
?
Blood Pressure
Improves
?
Blood Flow
Improves
?
Heart Rate Variability
Improves
?
Lung Function
1 study
Improves
C
Asthma Symptoms
Small Improvement
smallImproves
?
Lung Function
1 study
Improves
C
C-Reactive Protein (CRP)
Small Decrease
1 study
smallImproves
?
Liver Fat
1 study
Improves
?
Liver Fibrosis
Improves
?
NF-kB Activity
1 study
Improves
?
TNF-Alpha
1 study
Improves
C
Blood Pressure
Small Improvement
smallImproves
?
Plasma Arginine
Improves
C
Blood Pressure
Small Improvement
smallImproves
?
Exercise Capacity
1 study
Improves
C
Blood Pressure
Small Improvement
smallImproves
?
Exercise Capacity
1 study
Improves
D
Aerobic Exercise Metrics
No effect
none
?
Heart Rate
Improves
?
Power Output
Improves
?
Blood glucose
2 studies
Improves
?
Blood Lactate (Exercise)
Worsens
?
Rating of Perceived Exertion
Improves
?
Fatigue Symptoms
1 study
Improves
?
Insulin
Worsens
?
Muscle Oxygenation
1 study
Improves
?
Muscular Endurance
Improves
?
Plasma Arginine
Improves
D
Aerobic Exercise Metrics
No effect
none
?
Power Output
Improves
?
DNA Damage
1 study
Worsens
?
Heart Rate
Improves
?
Immunity
Improves
?
Muscular Endurance
Improves
?
Oxidative Stress Biomarkers
1 study
Improves
?
Plasma Arginine
Improves
?
Rating of Perceived Exertion
Improves
D
Aerobic Exercise Metrics
No effect
none
D
Anaerobic Capacity
No effect
1 study
none
?
Power Output
Improves
?
Blood Lactate (Exercise)
Worsens
?
Muscular Endurance
Improves
?
Blood Pressure
Improves
?
Fatigue Symptoms
3 studies
Improves
?
Heart Rate
Improves
?
Blood glucose
2 studies
Improves
?
Body Fat
Improves
?
Muscle Oxygenation
2 studies
Improves
?
Muscle Soreness
Improves
?
Urea
2 studies
Improves
?
Arterial Stiffness
Improves
?
Bilirubin
1 study
Worsens
?
Hemoglobin
1 study
Improves
?
Hydration (Total Body Water)
1 study
Improves
?
Insulin
Worsens
?
Kidney Function
1 study
Improves
?
Liver Enzymes
1 study
Worsens
?
Muscle Mass
1 study
Improves
?
Oxygen Uptake
Improves
?
Rating of Perceived Exertion
Improves
?
Red Blood Cell Count
1 study
Improves
?
Serum Albumin
1 study
Improves
?
Strength
1 study
Improves
?
Training Volume
1 study
Improves
?
Weight
Improves
?
White Blood Cell Count
1 study
Improves
D
Anaerobic Capacity
No effect
1 study
none
?
Power Output
Improves
?
Muscular Endurance
Improves
?
Blood Lactate (Exercise)
Worsens
?
Blood Pressure
Improves
?
Fatigue Symptoms
2 studies
Improves
?
Heart Rate
Improves
?
Muscle Soreness
Improves
?
Urea
2 studies
Improves
?
Bilirubin
1 study
Worsens
?
Body Fat
Improves
?
Hemoglobin
1 study
Improves
?
Hydration (Total Body Water)
1 study
Improves
?
Kidney Function
1 study
Improves
?
Liver Enzymes
1 study
Worsens
?
Muscle Mass
1 study
Improves
?
Muscle Oxygenation
1 study
Improves
?
Rating of Perceived Exertion
Improves
?
Red Blood Cell Count
1 study
Improves
?
Serum Albumin
1 study
Improves
?
Strength
1 study
Improves
?
Training Volume
1 study
Improves
?
Weight
Improves
?
White Blood Cell Count
1 study
Improves
D
Blood glucose
No effect
1 study
none
?
Insulin
Worsens
?
Growth Hormone
Improves
?
Plasma Glutamine
2 studies
Improves
?
Creatinine
1 study
Improves
?
IGF-1
1 study
Improves
?
Muscle protein synthesis (MPS)
1 study
Improves
?
Nitric Oxide
1 study
Improves
?
Plasma Arginine
Improves
?
Urea
1 study
Improves
D
Anti-Oxidant Enzyme Profile
No effect
1 study
none
?
Blood glucose
1 study
Improves
?
Oxidative Stress Biomarkers
1 study
Improves
?
Plasma Nitrate
1 study
Improves
?
Total Antioxidant Capacity (TAC)
Improves
D
Aerobic Exercise Metrics
No effect
none
?
Power Output
Improves
D
DNA Damage
No effect
1 study
none
?
Immunity
Improves
?
Liver Enzymes
1 study
Worsens
?
Oxidative Stress Biomarkers
1 study
Improves
D
Anaerobic Capacity
No effect
1 study
none
?
Power Output
Improves
?
Strength
1 study
Improves
D
Anaerobic Capacity
No effect
1 study
none
?
Power Output
Improves
?
Muscular Endurance
Improves
?
Blood Lactate (Exercise)
Worsens
?
Blood Pressure
Worsens
?
Fatigue Symptoms
2 studies
Worsens
?
Heart Rate
Worsens
?
Muscle Soreness
Worsens
?
Urea
2 studies
Improves
?
Bilirubin
1 study
Worsens
?
Body Fat
Worsens
?
Hemoglobin
1 study
Improves
?
Hydration (Total Body Water)
1 study
Improves
?
Kidney Function
1 study
Improves
?
Liver Enzymes
1 study
Worsens
?
Muscle Mass
1 study
Improves
?
Muscle Oxygenation
1 study
Improves
?
Rating of Perceived Exertion
Improves
?
Red Blood Cell Count
1 study
Improves
?
Serum Albumin
1 study
Improves
?
Strength
1 study
Improves
?
Training Volume
1 study
Improves
?
Weight
Worsens
?
White Blood Cell Count
1 study
Improves
?
Blood Flow
Improves
?
Erections
Improves

Evidence by Condition

Best grade per condition (each condition may have multiple outcomes)

BHeart Failure
1
Blood PressureImprovesRight Ventricular Ejection FractionImprovesExercise ToleranceImproves
CTennis Performance
2
Anaerobic CapacityPower OutputImprovesStrengthImproves
CHigh Blood Pressure
1
Arterial StiffnessImprovesBlood PressureImprovesBlood FlowImproves
CMuscle Recovery
1
Blood FlowImprovesBlood Lactate (Exercise)WorsensMuscle SorenessImproves
CObesity
1
Asthma SymptomsImprovesBlood PressureImprovesBlood FlowImproves
CAsthma
1
Asthma SymptomsImprovesLung FunctionImproves
CNonalcoholic Fatty Liver Disease (NAFLD)
1
C-Reactive Protein (CRP)ImprovesLiver FatImprovesLiver FibrosisImproves
CCardiovascular Disease
1
Blood PressureImprovesPlasma ArginineImproves
CEisenmenger Syndrome
1
Blood PressureImprovesExercise CapacityImproves
CPulmonary Hypertension
1
Blood PressureImprovesExercise CapacityImproves
DGeneral Athletic Performance
1
Aerobic Exercise MetricsAnaerobic CapacityPower OutputImproves
DAerobic Exercise Performance
1
Aerobic Exercise MetricsHeart RateImprovesPower OutputImproves
DCycling Performance
1
Aerobic Exercise MetricsPower OutputImprovesDNA DamageWorsens
DMetabolic Health
1
Blood glucoseInsulinWorsensGrowth HormoneImproves
DType 2 Diabetes
1
Anti-Oxidant Enzyme ProfileBlood glucoseImprovesOxidative Stress BiomarkersImproves
DAnaerobic Exercise Performance
1
Aerobic Exercise MetricsPower OutputImproves
DImmune Health
1
DNA DamageImmunityImprovesLiver EnzymesWorsens
DMuscle Size & Strength
1
Anaerobic CapacityPower OutputImprovesMuscular EnduranceImproves

Research Citations (45)

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