Tyrosine × Levodopa
MODERATE
Probable Evidence
Mechanism
Tyrosine and levodopa compete for the same intestinal absorption transporter.
Effect
Reduced levodopa absorption; worsening Parkinson's symptoms
Management
Separate doses by at least 2 hours.
Plain Language Summary
AI-generated · Qwen 3.6 · grounded in 2 sources · methodologyThis combination can cause issues because tyrosine and levodopa compete for the same pathway to enter your bloodstream. This competition can reduce how much medication is absorbed, which may lead to worsening Parkinson's symptoms.
Source
Glover V et al. J Neural Transm 1980
Research
Supporting Research
Baseline-dependent effect of dopamine's precursor L-tyrosine on working memory gating but not updating
Effects of Five Amino Acids (Serine, Alanine, Glutamate, Aspartate, and Tyrosine) on Mental Health in Healthy Office Workers: A Randomized, Double-Blind, Placebo-Controlled Exploratory Trial.
Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial.
Behavioral and cognitive effects of tyrosine intake in healthy human adults
Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults
The catecholamine neurotransmitter precursor tyrosine increases anger during exposure to severe psychological stress
Dopamine depletion effects on cognitive flexibility as modulated by tDCS of the dlPFC.
Tyrosine negatively affects flexible-like behaviour under cognitively demanding conditions.
Medical Disclaimer: This interaction record is for informational and educational purposes only and does not constitute medical advice. Always consult your healthcare provider or pharmacist before combining any supplement with prescription medications.