Melatonin for Parkinson's Disease
Also known as: N-acetyl-5-methoxytryptamine
Melatonin decline correlates with REM sleep behavior disorder — a prodromal Parkinson's symptom — and may have neuroprotective effects on dopaminergic neurons.
Mechanism of Action
Melatonin protects dopaminergic neurons through direct mitochondrial antioxidant effects, MT2 receptor-mediated anti-apoptotic signaling, and autophagy promotion for α-synuclein clearance. It modulates dopamine metabolism to reduce oxidative DA metabolites.
General mechanism: Pineal hormone. Mitochondrial antioxidant, Nrf2 activator, NLRP3 inhibitor, circadian regulator, anti-amyloid, immunomodulator.
Current Evidence
PD patients have reduced melatonin. Supplementation improves RBD and sleep quality. Preclinical models show dopaminergic neuroprotection. No large disease-modification trials.
Clinical Status: Established for PD-related sleep disorders. Neuroprotection studies preclinical.
Safety Profile
Extremely safe even at high doses. Drowsiness. No addiction potential. May affect reproductive hormones at very high doses.
Key Research Questions
- Can melatonin in RBD patients prevent conversion to Parkinson's?
- Does melatonin reduce α-synuclein aggregation in vivo?