Medication interaction hub

What Supplements Interact with Levodopa, Carbidopa?

Levodopa, Carbidopa brand name: Duodopa. Every interaction below applies to the brands too.

26 Interactions 7 Major 17 Moderate 2 Minor
Curated & coded by · Clinical Pharmacist · Updated September 29, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Levodopa, Carbidopa? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Levodopa, Carbidopa against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

Cowhage is the first thing to know here. It naturally contains levodopa, sometimes 75 to 400 mg per dose, so stacking it on Levodopa, Carbidopa (Duodopa) risks levodopa excess. That entry sets the tone for a page worth studying, not skimming. Seven of the 26 ingredients rate major, and most of the rest pull the other way, blunting the drug. Protein powders and single amino acid supplements compete with levodopa for transport into the gut and brain, while magnesium and iron can sharply cut absorption.

Since Parkinson's control depends on steady levodopa reaching the brain, less of it means tremor, stiffness, and on-off swings creeping back. Six ingredients may also lower the seizure threshold, and a couple, combined with carbidopa, can add serotonin-related side effects. If you need iron or magnesium, space the doses well apart and let the full report and your pharmacist settle the timing.

— , Clinical Pharmacist · July 18, 2026

Major 7 Moderate 17 Minor 2 No known interaction 1,426

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Top Ingredient Interactions

Levodopa, Carbidopa: Top Interactions at a Glance

The most significant Levodopa, Carbidopa supplement & herbal interactions, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 26 interacting ingredients — plus 1,426 more checked with no known interaction. See the complete ranked list.

Start here

The Major Interactions to Know About

The most clinically significant Levodopa, Carbidopa + supplement combinations in our database, best-documented first. Open any card for the full report.

Major Likelihood Likely Cowhage + Levodopa, Carbidopai

Concomitant use can increase the risk of levodopa-related adverse effects.

Read the full interaction Major Likelihood Probable Branched-chain Amino Acids (bcaa) + Levodopa, Carbidopai

BCAAs in large doses can reduce the effects of levodopa.

Read the full interaction Major Likelihood Probable Indian Snakeroot + Levodopa, Carbidopai

Theoretically, taking Indian snakeroot with levodopa may reduce the effectiveness of levodopa.

Read the full interaction Major Likelihood Probable Magnesium + Levodopa, Carbidopai

Magnesium can reduce the bioavailability of levodopa/carbidopa.

Read the full interaction Major Likelihood Probable Phenylalanine + Levodopa, Carbidopai

Phenylalanine, especially in high doses, can reduce the effectiveness of levodopa.

Read the full interaction Major Likelihood Probable Rauvolfia Vomitoria + Levodopa, Carbidopai

Theoretically, Rauvolfia vomitoria might reduce the effects of levodopa.

Read the full interaction
The complete list

Every Supplement Checked Against Levodopa, Carbidopa

All 1,452 ingredients in our database, ranked by severity — 26 with a Levodopa, Carbidopa interaction on file and 1,426 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Levodopa, Carbidopa?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Magnesium with Levodopa, Carbidopa?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Magnesium can reduce the bioavailability of levodopa/carbidopa.

Full Magnesium + Levodopa, Carbidopa answer

Can you take Vitamin B6 with Levodopa, Carbidopa?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.

Full Vitamin B6 + Levodopa, Carbidopa answer

Can you take Phenylalanine with Levodopa, Carbidopa?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Phenylalanine, especially in high doses, can reduce the effectiveness of levodopa.

Full Phenylalanine + Levodopa, Carbidopa answer

Can you take Tyrosine with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, tyrosine might decrease the effectiveness of levodopa.

Full Tyrosine + Levodopa, Carbidopa answer

Can you take 5-htp with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Combining 5-HTP and carbidopa can increase the risk of serotonergic side effects.

Full 5-htp + Levodopa, Carbidopa answer

Can you take Ayahuasca with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, ayahuasca might have additive effects when used with dopamine agonists.

Full Ayahuasca + Levodopa, Carbidopa answer

Can you take Banana with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Taking banana may reduce the effectiveness of levodopa.

Full Banana + Levodopa, Carbidopa answer

Can you take Biofeedback with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. There is some concern that electroencephalogram (EEG) biofeedback might lower the seizure threshold in some patients.

Full Biofeedback + Levodopa, Carbidopa answer

Can you take Black Horehound with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, black horehound might have additive effects when used with dopamine agonists.

Full Black Horehound + Levodopa, Carbidopa answer

Can you take Dendrobium with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. The dendrobium constituent dendrobine is reported to have convulsant effects.

Full Dendrobium + Levodopa, Carbidopa answer

Can you take Ginkgo with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking ginkgo with drugs that lower the seizure threshold might increase the risk for convulsions.

Full Ginkgo + Levodopa, Carbidopa answer

Can you take Griffonia Simplicifolia with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking Griffonia simplicifolia seed extract with carbidopa might increase the risk of serotonergic and other adverse effects.

Full Griffonia Simplicifolia + Levodopa, Carbidopa answer

Can you take Melatonin with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking melatonin with drugs that lower the seizure threshold might increase the risk of seizure activity.

Full Melatonin + Levodopa, Carbidopa answer

Can you take Rauwolscine with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking rauwolscine with seizure threshold lowering drugs might increase the risk of adverse convulsant effects.

Full Rauwolscine + Levodopa, Carbidopa answer

Can you take Same with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. SAMe might reduce the effectiveness of levodopa.

Full Same + Levodopa, Carbidopa answer

Can you take Syrian Rue with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Syrian rue might increase the adverse effects of dopamine agonists.

Full Syrian Rue + Levodopa, Carbidopa answer

Can you take Thuja with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Thuja products can contains significant amounts of thujone, a neurotoxin.

Full Thuja + Levodopa, Carbidopa answer

Can you take Vitex Agnus-castus with Levodopa, Carbidopa?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, vitex agnus-castus could interfere with dopamine agonists.

Full Vitex Agnus-castus + Levodopa, Carbidopa answer

Can you take Caffeic Acid with Levodopa, Carbidopa?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, caffeic acid might increase the levels and clinical effects of levodopa.

Full Caffeic Acid + Levodopa, Carbidopa answer

Can you take Cowhage with Levodopa, Carbidopa?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Concomitant use can increase the risk of levodopa-related adverse effects.

Full Cowhage + Levodopa, Carbidopa answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Levodopa, Carbidopa is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Levodopa, Carbidopa, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Levodopa, Carbidopa sits in 5 interaction categories. Open any one to see what the group means:

Levodopa 12 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

12 of the supplement ingredients on this page reach Levodopa, Carbidopa through this category.

Seizure Threshold Lowering Drugs 6 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

6 of the supplement ingredients on this page reach Levodopa, Carbidopa through this category.

Dopamine Agonists 4 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

4 of the supplement ingredients on this page reach Levodopa, Carbidopa through this category.

Carbidopa (Lodosyn) 2 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

2 of the supplement ingredients on this page reach Levodopa, Carbidopa through this category.

Levodopa/Carbidopa (Sinemet) 2 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

2 of the supplement ingredients on this page reach Levodopa, Carbidopa through this category.

Related: does Levodopa, Carbidopa deplete any nutrients?

Levodopa, Carbidopa has 2 reported nutrient associations in the research literature — see the Levodopa, Carbidopa nutrient depletion report.

Check a real product

Take a Supplement Product? Check the Whole Bottle Against Levodopa, Carbidopa

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Levodopa, Carbidopa.

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Pharmacist Counseling Corner

Levodopa, Carbidopa & Supplements: Common Questions

What supplements interact with Levodopa, Carbidopa?
More than you might expect — 26 in total, though they are far from equal: 7 are rated major, 17 moderate, and 2 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: Cowhage, Branched-chain Amino Acids (bcaa), Indian Snakeroot.
Which Levodopa, Carbidopa supplement interactions are the most serious?
Focus on the major group: Cowhage, Branched-chain Amino Acids (bcaa), Indian Snakeroot, Magnesium and Phenylalanine, among others. A major rating means the combination can be clinically significant, not that harm is guaranteed — but it's exactly the kind of thing to run past your pharmacist before your next dose, not after. Jump to the ranked list.
Can I take vitamins or supplements while on Levodopa, Carbidopa?
Usually yes — most people on Levodopa, Carbidopa can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like Duodopa have the same supplement interactions as Levodopa, Carbidopa?
Yes — Duodopa all contain Levodopa, Carbidopa, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
Does Levodopa, Carbidopa deplete any vitamins or nutrients?
It might — Levodopa, Carbidopa has 2 reported nutrient-depletion associations in the research literature, which is a different question from interactions: instead of a supplement changing the drug, the drug may lower a nutrient over time. See the Levodopa, Carbidopa nutrient depletion report for the specifics and what to discuss with your pharmacist.
What about Levodopa, Carbidopa and my other medications?
This page covers Levodopa, Carbidopa against supplements and herbal ingredients. Checking Levodopa, Carbidopa against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 29, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.