L-Tyrosine

L-Tyrosine is an amino acid that is used as a precursor for the synthesis of the catecholamines dopamine (DA) and norepinephrine (NE). DA and NE are depleted under stressful conditions, which can compromise cognitive function. L-Tyrosine supplementation may help alleviate acute stress-induced cognitive decline by restoring catecholamine levels in the brain.

Quick Answer

What it is

L-Tyrosine is an amino acid that is used as a precursor for the synthesis of the catecholamines dopamine (DA) and norepinephrine (NE). DA and NE are depleted under stressful conditions, which can compromise cognitive function.

Key findings

  • Grade C: Adrenaline (Metabolic Health)
  • Grade C: Motor Control (Fatigue)
  • Grade C: Attention (Narcolepsy)

Safety

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

ℹ️ Quick Facts: L-Tyrosine

Quick Facts: L-Tyrosine

  • Best Evidence:Grade C
  • Conditions Studied:20
  • Research Outcomes:182
  • Key Effect:Metabolic Health
Outcomes by grade:
A0
B0
C7
D14
20 conditions Β· 182 outcomes

Detailed Outcomes

Grade:
Effect:
Size:
Sort:
|
C
Adrenaline
Mixed effect
3 studies
?
Noradrenaline
3 studies
↑Improves
?
Dopamine
↑Improves
?
Heart Rate
↓Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Blood Pressure
1 study
↓Improves
?
Renin Activity
↑Improves
C
Adrenaline
Mixed effect
1 study
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
2 studies
↑Worsens
?
Muscular Endurance
2 studies
↑Improves
?
Strength
2 studies
↑Improves
?
Adrenocorticotropic Hormone
1 study
↑Improves
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Alertness
↑Improves
?
Cortisol
1 study
↓Improves
?
Dopamine
↑Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Heart Rate
↓Improves
?
Noradrenaline
1 study
↑Improves
?
Power Output
1 study
↑Improves
?
Reaction Time
↑Improves
?
Subjective Well-Being
1 study
↑Improves
?
Working Memory
↑Improves
C
Adrenaline
Mixed effect
1 study
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
2 studies
↑Worsens
?
Adrenocorticotropic Hormone
1 study
↑Improves
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Cortisol
1 study
↓Improves
?
Dopamine
↑Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Heart Rate
↓Improves
?
Muscular Endurance
1 study
↑Improves
?
Noradrenaline
1 study
↑Improves
?
Power Output
1 study
↑Improves
?
Strength
1 study
↑Improves
C
Adrenaline
Mixed effect
1 study
?
Heart Rate
↓Improves
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Alertness
↑Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Dopamine
↑Improves
?
Noradrenaline
1 study
↑Improves
?
Power Output
1 study
↑Improves
?
Vigor/Activity
1 study
↑Improves
C
Motor Control
Small Improvement
1 study
small↑Improves
?
Sleep Deprivation Symptoms
1 study
↓Improves
?
Working Memory
↑Improves
C
Attention
Small Improvement
1 study
small↑Improves
?
Narcolepsy Symptoms
↓Improves
?
Sleep Latency
1 study
↓Improves
C
Impulse Control
Small Increase
small↑Improves
?
Subjective Well-Being
1 study
↑Improves
D
Aerobic Exercise Metrics
No effect
4 studies
none
?
Heart Rate
↓Improves
?
Rating of Perceived Exertion
↑Improves
?
Body Temperature
↑Improves
?
Power Output
2 studies
↑Improves
?
Alertness
↑Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Vigor/Activity
1 study
↑Improves
?
Weight
1 study
↓Improves
D
Aerobic Exercise Metrics
No effect
4 studies
none
?
Heart Rate
↑Worsens
?
Rating of Perceived Exertion
↑Improves
?
Body Temperature
↑Improves
?
Power Output
2 studies
↑Improves
?
Alertness
↑Improves
?
Blood glucose
↑Worsens
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Vigor/Activity
1 study
↑Improves
?
Weight
1 study
↑Worsens
D
Alertness
No effect
none
D
Adrenocorticotropic Hormone
No effect
1 study
none
?
Working Memory
↑Improves
?
Blood Pressure
4 studies
↓Improves
?
Attention
3 studies
↑Improves
?
Cortisol
2 studies
↓Improves
?
Reaction Time
↑Improves
?
Depression Symptoms
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Motor Control
1 study
↑Improves
?
Muscular Endurance
1 study
↑Improves
?
Noradrenaline
1 study
↑Improves
?
Processing Accuracy
1 study
↑Improves
?
Processing Speed
1 study
↑Improves
?
Sleep Deprivation Symptoms
1 study
↓Improves
?
Strength
1 study
↑Improves
?
Stress Signs and Symptoms
1 study
↓Improves
?
Subjective Well-Being
1 study
↑Improves
?
Vigor/Activity
1 study
↑Improves
D
Blood Pressure
No effect
2 studies
none
?
Heart Rate
↓Improves
?
Body Temperature
↑Improves
?
Cortisol
1 study
↓Improves
?
Pulse Pressure
1 study
↑Improves
?
Reaction Time
↑Improves
D
Aerobic Exercise Metrics
No effect
2 studies
none
?
Heart Rate
↓Improves
?
Rating of Perceived Exertion
↑Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Free Fatty Acids
1 study
↑Improves
?
Oxygen Uptake
1 study
↑Improves
?
Power Output
1 study
↑Improves
?
Weight
1 study
↓Improves
D
Adrenocorticotropic Hormone
No effect
1 study
none
?
Aerobic Exercise Metrics
2 studies
↑Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
2 studies
↑Worsens
?
Cortisol
1 study
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Free Fatty Acids
1 study
↑Improves
?
Heart Rate
↓Improves
?
Muscular Endurance
1 study
↑Improves
?
Oxygen Uptake
1 study
↑Improves
?
Rating of Perceived Exertion
↑Improves
?
Strength
1 study
↑Improves
D
Blood Pressure
No effect
1 study
none
?
Heart Rate
↓Improves
?
Noradrenaline
1 study
↑Improves
D
Blood Pressure
No effect
1 study
none
?
Working Memory
↑Improves
?
Noradrenaline
1 study
↑Improves
D
Adrenocorticotropic Hormone
No effect
1 study
none
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Cortisol
1 study
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Muscular Endurance
1 study
↑Improves
?
Strength
1 study
↑Improves
?
Subjective Well-Being
1 study
↑Improves
D
Blood Pressure
No effect
1 study
none
?
Heart Rate
↓Improves
?
Noradrenaline
1 study
↑Improves
?
Oxygen Uptake
1 study
↑Improves
D
Adrenocorticotropic Hormone
No effect
1 study
none
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Blood glucose
↓Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Cortisol
1 study
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Muscular Endurance
1 study
↑Improves
?
Strength
1 study
↑Improves
D
Memory
No effect
1 study
none
?
Schizophrenia symptoms
↓Improves
D
Adrenocorticotropic Hormone
No effect
1 study
none
?
Aerobic Exercise Metrics
1 study
↑Improves
?
Blood Lactate (Exercise)
1 study
↑Worsens
?
Cortisol
1 study
↑Worsens
?
Fatigue Symptoms
1 study
↑Worsens
?
Muscular Endurance
1 study
↑Improves
?
Strength
1 study
↑Improves
?
Subjective Well-Being
1 study
↑Improves
?
Heart Rate
↓Improves
?
Anger
Small Detriment
1 study
small
?
Attention
1 study
↑Improves
?
Cortisol
1 study
↓Improves
?
Depression Symptoms
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Processing Accuracy
1 study
↑Improves
?
Stress Signs and Symptoms
1 study
↓Improves
?
Subjective Well-Being
1 study
↑Improves
?
Vigor/Activity
1 study
↑Improves
?
Working Memory
↑Improves
?
Heart Rate
↓Improves
?
Anger
Small Detriment
1 study
small
?
Attention
1 study
↑Improves
?
Blood Pressure
1 study
↓Improves
?
Cortisol
1 study
↓Improves
?
Depression Symptoms
↓Improves
?
Fatigue Symptoms
1 study
↓Improves
?
Processing Accuracy
1 study
↑Improves
?
Stress Signs and Symptoms
1 study
↓Improves
?
Subjective Well-Being
1 study
↑Improves
?
Vigor/Activity
1 study
↑Improves
?
Working Memory
↑Improves
?
Depression Symptoms
↓Improves

Evidence by Condition

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

CMetabolic Health
1
Adrenaline↑NoradrenalineImproves↑DopamineImproves
CGeneral Athletic Performance
1
Adrenaline↓Blood glucoseImproves↑Blood Lactate (Exercise)Worsens
CAnaerobic Exercise Performance
1
Adrenaline↓Blood glucoseImproves↑Blood Lactate (Exercise)Worsens
CSoccer Performance
1
Adrenaline↓Heart RateImproves↑Aerobic Exercise MetricsImproves
CFatigue
1
↑Motor ControlImproves↓Sleep Deprivation SymptomsImproves↑Working MemoryImproves
CNarcolepsy
1
↑AttentionImproves↓Narcolepsy SymptomsImproves↓Sleep LatencyImproves
CWeight Loss & Maintenance
1
↑Impulse ControlImproves↑Subjective Well-BeingImproves
DCognitive Improvement
1
AlertnessAdrenocorticotropic Hormone↑Working MemoryImproves
DAerobic Exercise Performance
1
Adrenocorticotropic Hormone↑Aerobic Exercise MetricsImproves↓Blood glucoseImproves
DCycling Performance
1
Aerobic Exercise Metrics↓Heart RateImproves↑Rating of Perceived ExertionImproves
DHigh Blood Pressure
1
Blood Pressure↓Heart RateImproves↑NoradrenalineImproves
DMemory Improvement
1
Blood Pressure↑Working MemoryImproves↑NoradrenalineImproves
DParkinson's Disease
1
Blood Pressure↓Heart RateImproves↑NoradrenalineImproves
DRunning Performance
1
Adrenocorticotropic Hormone↑Aerobic Exercise MetricsImproves↓Blood glucoseImproves
DSchizophrenia
1
Memory↓Schizophrenia symptomsImproves
DWarm- or Hot-Weather Exercise Performance
1
Aerobic Exercise Metrics↑Heart RateWorsens↑Rating of Perceived ExertionImproves
DMuscle Size & Strength
1
Adrenocorticotropic Hormone↑Aerobic Exercise MetricsImproves↑Blood Lactate (Exercise)Worsens

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