Medication·Interactions & depletion·Reviewed June 9, 2026
Levodopa/Carbidopa interactions.
Levodopa/Carbidopa has 6 documented interactions in the NutriStack database. Prolonged use is also associated with lower Vitamin B6, Vitamin B12, and Folate. The full interaction list, depletion table, and replacement suggestions are below. None of this is a substitute for your prescriber's advice.
Levodopa/Carbidopa at a glance.
A quick, data-grounded summary. The full tables are below.
Levodopa/Carbidopa has 6 documented interactions in the NutriStack database. Prolonged use is also associated with lower Vitamin B6, Vitamin B12, and Folate. The full interaction list, depletion table, and replacement suggestions are below. None of this is a substitute for your prescriber's advice.
Substances that interact with levodopa/carbidopa.
Every supplement and medication in the NutriStack database with a documented interaction with this drug, highest-severity first. Open any pair for the mechanism and sources.
| Substance | Interaction | What happens |
|---|---|---|
| 5-HTP | Caution | 5-HTP and levodopa may compete for the same amino acid transport systems (large neutral amino acid transporter) across the blood-brain barrier and... |
| Green Tea Extract | Caution | Green tea extract can contain concentrated EGCG and other catechins that inhibit catechol-O-methyltransferase in preclinical levodopa models. That... |
| Vitamin B6 | Caution | Vitamin B6 (pyridoxine) is a cofactor for DOPA decarboxylase, which converts levodopa to dopamine peripherally before it reaches the brain. While... details → |
| BCAAs | Timing Sensitive | BCAA supplements can reduce or delay levodopa's benefit because branched-chain amino acids compete with levodopa for the same intestinal and... details → |
| Iron | Timing Sensitive | Iron chelates levodopa in the GI tract, forming insoluble complexes that significantly reduce levodopa absorption. This can worsen Parkinson's... details → |
| L-Tyrosine | Timing Sensitive | L-tyrosine is a large neutral amino acid and can theoretically compete with levodopa for intestinal and blood-brain barrier transport when taken in... |
What levodopa/carbidopa can deplete.
Nutrients this medication is associated with lowering over time, with the mechanism, a suggested replacement where one applies, and the biomarker to monitor. Discuss any replacement with your prescriber first.
| Nutrient | Severity | How it happens | Replace with | Monitor |
|---|---|---|---|---|
| Vitamin B6 | Moderate | Carbidopa can bind pyridoxal phosphate and reduce functional vitamin B6 availability during chronic levodopa-carbidopa therapy. | Pyridoxine only with prescriber guidance | Plasma PLP + neurologic symptoms |
| Vitamin B12 | Mild | Levodopa methylation increases homocysteine burden, and low B12 status can worsen this metabolic effect during chronic therapy. | Methylcobalamin | Serum B12 + methylmalonic acid + homocysteine |
| Folate | Mild | Levodopa methylation can increase methyl-donor demand, making folate status clinically relevant when homocysteine rises on chronic therapy. | Folate per clinician guidance | Serum folate or RBC folate + homocysteine |
The full levodopa/carbidopa profile.
Uses, typical dosing, side effects, and the cited evidence for this medication.
Common levodopa/carbidopa questions.
Quick answers drawn from the tables above.
What interacts with Levodopa/Carbidopa?
In the NutriStack database, Levodopa/Carbidopa has 6 documented interactions. The most notable include 5-HTP, Green Tea Extract, Vitamin B6, BCAAs, and Iron. Check any specific combination before taking it and confirm with your prescriber.
Does Levodopa/Carbidopa deplete any nutrients?
Levodopa/Carbidopa is associated with lowering Vitamin B6, Vitamin B12, and Folate with prolonged use. Useful biomarkers to monitor include Plasma PLP + neurologic symptoms, Serum B12 + methylmalonic acid + homocysteine, and Serum folate or RBC folate + homocysteine. Ask your prescriber before adding any replacement supplement.
Is it safe to take 5-HTP with Levodopa/Carbidopa?
NutriStack classifies the 5-HTP and Levodopa/Carbidopa pairing as caution: 5-HTP and levodopa may compete for the same amino acid transport systems (large neutral amino acid transporter) across the blood-brain barrier and for AADC enzyme... Use caution when combining 5-HTP with levodopa/carbidopa. If considering 5-HTP for mood support, discuss with your neurologist first. Monitor for... Always confirm with your prescriber.
Check your whole stack
See how levodopa/carbidopa fits your supplements.
NutriStack screens your full routine for interactions and depletions, and updates the moment you change it.