Drug & supplement interaction

Sulforaphane + Levodopa

Levodopa brand names: Larodopa, Inbrija.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Sulforaphane and Levodopa in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Sulforaphane and Levodopa

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Levodopa and Sulforaphane in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Sulforaphane safety at a glance

Sulforaphane overall Use caution Sulforaphane from food is considered safe, but concentrated supplements are less studied for long-term use.
Pregnancy Likely Safe When used orally in amounts found in foods. There is insufficient reliable information available about the safety of sulforaphane in medicinal amounts. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts found in foods. There is insufficient reliable information available about the safety of sulforaphane in medicinal amounts. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Levodopa and Sulforaphane? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Levodopa

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levodopa is filed under 5 classifications — including dopamine agonists, seizure threshold lowering drugs, oral drugs. Sulforaphane has documented interactions with 3 drug classes — the most serious being cytochrome p450 1a2 (cyp1a2) substrates (moderate), cytochrome p450 2e1 (cyp2e1) substrates (moderate) and cytochrome p450 3a4 (cyp3a4) substrates (moderate) — and none of Levodopa’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Sulforaphane Does Interact With Other Medications

Sulforaphane has 722 moderate known drug interactions in our database — Levodopa isn’t one of them. If you take anything else, check it against the full list below.

Moderate 722 No known interaction 2,108 (incl. Levodopa)
Taking anything else?

Check Another of Your Medications Against Sulforaphane

Covers the 2,830 medications we’ve checked against Sulforaphane. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Sulforaphane and Levodopa May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Trouble sleeping / Headache Additional detail

    Sulforaphane

    “Orally, sulforaphane has been reported to cause headache in one clinical study. In another clinical trial, insomnia and irritability were reported. Sulforaphane has also been associated with two cases of seizure in males with autism. In one case, a patient with a recent history of seizure experienced a seizure after taking sulforaphane for 3 weeks.”

    Sulforaphane · Natural Medicines adverse-effect record, reported in autism spectrum disorder.

    3 sources cited
    1. 104537. Momtazmanesh S, Amirimoghaddam-Yazdi Z, Moghaddam HS, Mohammadi MR, Akhondzadeh S. Sulforaphane as an adjunctive treatment for irritability in children with autism spectrum disorder: A randomized, double-blind, placebo-controlled clinical trial. Psychiatr PubMed
    2. 108131. Zimmerman AW, Singh K, Connors SL, et al. Randomized controlled trial of sulforaphane and metabolite discovery in children with Autism Spectrum Disorder. Mol Autism 2021;12(1):38.
    3. 95267. Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc Natl Acad Sci U S A. 2014;111(43):15550-5. PubMed

    Levodopa

    Listed in the ADVERSE REACTIONS section of the FDA label for Levodopa. Read the label on DailyMed ›

  • Vomiting Additional detail

    Sulforaphane

    “Orally, sulforaphane and sulforaphane-rich extracts can cause bowel discomfort, stomach upset, heartburn, and vomiting. A specific stabilized form of sulforaphane (Cavamax W6) caused mild stomach upset in 60% of subjects in a small study. However, in some clinical studies, the gastrointestinal side effects reported with sulforaphane did not occur more frequently than with placebo.”

    Sulforaphane · Natural Medicines adverse-effect record, reported in dyspepsia.

    6 sources cited
    1. 95251. Cipolla BG, Mandron E, Lefort JM, et al. Effect of sulforaphane in men with biochemical recurrence after radical prostatectomy. Cancer Prev Res (Phila). 2015;8(8):712-9. PubMed
    2. 95252. Fahey JW, Wade KL, Wehage SL, et al. Stabilized sulforaphane for clinical use: Phytochemical delivery efficiency. Mol Nutr Food Res. 2017 Apr;61(4). PubMed
    3. 95260. Alumkal JJ, Slottke R, Schwartzman J, et al. A phase II study of sulforaphane-rich broccoli sprout extracts in men with recurrent prostate cancer. Invest New Drugs. 2015;33(2):480-9. PubMed
    4. 95265. Heber D, Li Z, Garcia-Lloret M, et al. Sulforaphane-rich broccoli sprout extract attenuates nasal allergic response to diesel exhaust particles. Food Funct. 2014;5(1):35-41. PubMed
    5. 95267. Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc Natl Acad Sci U S A. 2014;111(43):15550-5. PubMed
    6. 95268. Wise RA, Holbrook JT, Criner G, et al. Lack of effect of oral sulforaphane administration on Nrf2 expression in COPD: A randomized, double-blind, placebo controlled trial. PLoS One. 2016;11(11):e0163716. PubMed

    Levodopa

    Listed in the ADVERSE REACTIONS section of the FDA label for Levodopa. Read the label on DailyMed ›

Reported for Sulforaphane but not commonly for Levodopa: weight gain, stomach upset, mood changes or irritability and heartburn.

Effects for Levodopa come from the ADVERSE REACTIONS section of its FDA label; effects for Sulforaphane come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Sulforaphane in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in amounts found in foods. There is insufficient reliable information available about the safety of sulforaphane in medicinal amounts.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Levodopa

This page covers Sulforaphane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levodopa page lists 41 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Branched-chain Amino Acids (bcaa) (major), Cowhage (major), Indian Snakeroot (major) and Magnesium (major).

By severity: 8 major · 22 moderate · 11 minor.

From our pharmacist’s overview on the Levodopa page

“Parkinson symptoms return fast when levodopa (Larodopa, Inbrija) stops reaching the brain, and most of the 41 supplements on this page can make that happen, so treat these combinations with genuine care. Protein and amino acid supplements compete with levodopa for transport into the brain, while everyday minerals like magnesium and iro…”

Reviewed by 2 · Jul 18, 2026

Open the Levodopa interaction page

One more smart check

Taking Sulforaphane as Part of a Dietary Supplement Product? Check It for Interactions

We hold 167 real supplement products containing Sulforaphane, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sulforaphane. Even though Sulforaphane itself has no known interaction with Levodopa, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Sulforaphane and Levodopa Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Sulforaphane
Top half

#368 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Levodopa
Top 25%

#317 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Sulforaphane reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Sulforaphane and Levodopa records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Sulforaphane

What is Sulforaphane?

  • Antioxidant support
  • General cellular health
  • Detoxification support
  • Inflammation
  • Skin and aging concerns

Sulforaphane is a natural compound found in broccoli and other cruciferous vegetables that has shown promising antioxidant and anti-inflammatory effects in lab studies, but strong human evidence for most specific health claims is still limited. It is generally well tolerated as part of a vegetable-rich diet, but if you take a concentrated supplement, talk to your pharmacist or doctor first.

Brassicaceae · Derived from cruciferous vegetables, especially broccoli sprouts and seeds · Capsules, tablets, powders, broccoli sprout extracts, and 'broccoli seed extract' supplements often standardized to glucoraphanin

An interaction check asks whether these two react with each other — it does not ask whether Sulforaphane is a good idea for someone in your situation. Here is what our Sulforaphane record says about it on its own.

Sulforaphane: dosing

There is no official, standardized dose of sulforaphane. Supplements vary widely in how they are made and how much active compound they actually deliver. Many products are labeled by glucoraphanin content or by 'active sulforaphane,' and the amount of usable sulforaphane can differ depending on whether the enzyme myrosinase is present.Because of this variability, the best approach is to follow the directions on the product label and not exceed the recommended amount.

From our Sulforaphane monograph — the full record covers uses, side effects and every documented interaction.

Read the full Sulforaphane monograph & all interactions
Medication

About Levodopa Oral Inhalation

What Is Levodopa Oral Inhalation Used For?

Brand names: Larodopa, Inbrija

Inbrija is used to treat OFF episodes in adults with Parkinson's disease. An OFF episode is when your regular oral carbidopa/levodopa medication temporarily stops working well enough, causing Parkinson's symptoms — such as stiffness, slowness, or tremor — to return.

Inbrija is used as needed when OFF symptoms start to come back. It is not a replacement for your regular oral carbidopa/levodopa; it works alongside it.

Most-Reported Side Effects for Levodopa

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fall 5,276 reports
Hallucination 4,813 reports
Tremor 3,805 reports
Dyskinesia 3,626 reports
Parkinson^s disease 3,449 reports
See full Levodopa Oral Inhalation drug information
Keep checking

Other Drugs & Sulforaphane

Browse every other medication we’ve checked against Sulforaphane — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
722Moderate
0Minor
2,107No known interaction
722 Moderate 2,107 No interaction
Moderate

722 interactions

Showing 60 of 722 moderate interactions — see all 722 on the Sulforaphane page.

No interaction 2,107 drugs checked — show the list

We also checked Sulforaphane against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,107 medications checked with no known interaction — see the full Sulforaphane list.

See the full Sulforaphane interactions page
See every supplement checked against Levodopa, ranked by severity
Evidence & sources

Sulforaphane References

The 16 references that drive our Sulforaphane monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Park EJ, Pezzuto JM. Botanicals in cancer chemoprevention. Cancer Metastasis Rev 2002;21:231-55. PubMed
  2. Barcelo S, Mace K, Pfeifer AM, Chipman JK. Production of DNA strand breaks by N-nitrosodimethylamine and 2-amino-3-methylimidazo[4,5-f]quinoline in THLE cells expressing human CYP isoenzymes and inhibition by sulforaphane. Mutat Res 1998;402:111-20. PubMed
  3. Cipolla BG, Mandron E, Lefort JM, et al. Effect of sulforaphane in men with biochemical recurrence after radical prostatectomy. Cancer Prev Res (Phila). 2015;8(8):712-9. PubMed
  4. Fahey JW, Wade KL, Wehage SL, et al. Stabilized sulforaphane for clinical use: Phytochemical delivery efficiency. Mol Nutr Food Res. 2017 Apr;61(4). PubMed
  5. Alumkal JJ, Slottke R, Schwartzman J, et al. A phase II study of sulforaphane-rich broccoli sprout extracts in men with recurrent prostate cancer. Invest New Drugs. 2015;33(2):480-9. PubMed
  6. Heber D, Li Z, Garcia-Lloret M, et al. Sulforaphane-rich broccoli sprout extract attenuates nasal allergic response to diesel exhaust particles. Food Funct. 2014;5(1):35-41. PubMed
  7. Singh K, Connors SL, Macklin EA, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc Natl Acad Sci U S A. 2014;111(43):15550-5. PubMed
  8. Wise RA, Holbrook JT, Criner G, et al. Lack of effect of oral sulforaphane administration on Nrf2 expression in COPD: A randomized, double-blind, placebo controlled trial. PLoS One. 2016;11(11):e0163716. PubMed
  9. Bent S, Lawton B, Warren T, et al. Identification of urinary metabolites that correlate with clinical improvements in children with autism treated with sulforaphane from broccoli. Mol Autism. 2018;9:35. PubMed
  10. Momtazmanesh S, Amirimoghaddam-Yazdi Z, Moghaddam HS, Mohammadi MR, Akhondzadeh S. Sulforaphane as an adjunctive treatment for irritability in children with autism spectrum disorder: A randomized, double-blind, placebo-controlled clinical trial. Psychiatr PubMed
  11. Fimognari C, Lenzi M, Hrelia P. Interaction of the isothiocyanate sulforaphane with drug disposition and metabolism: pharmacological and toxicological implications. Curr Drug Metab. 2008;9(7):668-78. PubMed
  12. Chinnappan SM, George A, Evans M, Anthony J. Efficacy of Labisia pumila and Eurycoma longifolia standardised extracts on hot flushes, quality of life, hormone and lipid profile of peri-menopausal and menopausal women: a randomised, placebo-controlled stud
  13. Mahéo K, Morel F, Langouët S, et al. Inhibition of cytochromes P-450 and induction of glutathione S-transferases by sulforaphane in primary human and rat hepatocytes. Cancer Res. 1997;57(17):3649-52.
  14. Yoxall V, Kentish P, Coldham N, Kuhnert N, Sauer MJ, Ioannides C. Modulation of hepatic cytochromes P450 and phase II enzymes by dietary doses of sulforaphane in rats: Implications for its chemopreventive activity. Int J Cancer. 2005;117(3):356-62. PubMed
  15. Zimmerman AW, Singh K, Connors SL, et al. Randomized controlled trial of sulforaphane and metabolite discovery in children with Autism Spectrum Disorder. Mol Autism 2021;12(1):38.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Sulforaphane and Levodopa Together: Common Questions

Is it safe to take Sulforaphane with Levodopa?
We do not list a known interaction between Sulforaphane and Levodopa. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Sulforaphane and Levodopa have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Sulforaphane and Levodopa combination checked?
Interactions in our licensed database are recorded against drug classes. Levodopa is filed under 5 classifications, and Sulforaphane has documented interactions with 3 drug classes — none of Levodopa's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Sulforaphane interact with any other medications?
Yes. Sulforaphane has 722 documented drug interactions in our database — Levodopa is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Levodopa interact with any supplements?
Yes. Levodopa has documented interactions with 41 supplements in our database — Sulforaphane is not one of them. The Levodopa interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Sulforaphane monograph Uses, safety profile, and every drug interaction in one place Levodopa Oral Inhalation drug information The full plain-English guide to this medication Levodopa supplement interactions Every supplement checked against Levodopa, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 16 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levodopa and Sulforaphane?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.