Drug & supplement interaction

Diindolylmethane + Ropinirole

Ropinirole brand names: Requip, Adartrel.

Minor Interaction
Medically reviewed by · Updated September 2026
The bottom line Minor

Diindolylmethane has a minor interaction with Ropinirole. Theoretically, diindolylmethane might lower serum levels of CYP1A2 substrates.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Diindolylmethane and Ropinirole

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Ropinirole

Ropinirole falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Diindolylmethane interacts with.

Theoretically, diindolylmethane might lower serum levels of CYP1A2 substrates.
In vitro evidence suggests that diindolylmethane can induce CYP1A2. Theoretically, it might increase metabolism of CYP1A2 substrates and lower serum concentrations. This interaction has not been reported in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea: your liver uses an enzyme called CYP1A2 to clear ropinirole out of your system. In lab dishes, DIM seems to speed that enzyme up. If that held true in people, your body might break ropinirole down a little faster, which could leave slightly less of it working. In theory, that might mean your Parkinson's or restless legs symptoms (tremor, stiffness, that urge to move your legs) aren't controlled quite as well.

The reassuring part: this is only seen in test-tube studies, never reported in actual patients, and it's rated minor and unlikely. So I wouldn't lose sleep over it. Still, since both can be dose-sensitive, just give your pharmacist or doctor a heads-up before adding DIM so they can keep an eye on how you're feeling.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lake BG, Tredger JM, Renwick AB, et al. 3'3-diindolylmethane induces CYP1A2 in cultured precision-cut human liver slices. Xenobiotica 1998;28:803-11. PubMed
  2. Jellinck, P. H., Forkert, P. G., Riddick, D. S., Okey, A. B., Michnovicz, J. J., and Bradlow, H. L. Ah receptor binding properties of indole carbinols and induction of hepatic estradiol hydroxylation. Biochem.Pharmacol. 3-9-1993;45(5):1129-1136. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Diindolylmethane Also Interacts With Other Medications

Diindolylmethane has 116 moderate, 152 minor known drug interactions in our database — the Ropinirole one above is one of them. If you take anything else, check it against the full list below.

Moderate 116 Minor 152 No known interaction 2,562 (incl. Ropinirole)
Taking anything else?

Check Another of Your Medications Against Diindolylmethane

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

From our Q&A

Questions About Diindolylmethane or Ropinirole

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Diindolylmethane or Ropinirole, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Ropinirole

This page covers Diindolylmethane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ropinirole page lists 101 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), African Wild Potato (moderate), Ashitaba (moderate) and Ayahuasca (moderate).

By severity: 1 major · 67 moderate · 33 minor.

From our pharmacist’s overview on the Ropinirole page

“Activated charcoal deserves the closest look on this page. It is the only one of the 101 entries rated major against ropinirole (Requip, Adartrel), because charcoal can bind the drug in the gut and shrink the amount that actually reaches you, and for someone relying on ropinirole for Parkinson's disease or restless legs, that can mean…”

Reviewed by 2 · Jul 18, 2026

Open the Ropinirole interaction page

One more smart check

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

We hold 933 real supplement products containing Diindolylmethane, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Diindolylmethane. Your product may carry other ingredients that interact with Ropinirole too, on top of Diindolylmethane — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Diindolylmethane and Ropinirole 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 Diindolylmethane
Top 25%

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

29 days ago today
Medication Ropinirole
Steady interest

#1,510 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.

Supplement

About Diindolylmethane

What is Diindolylmethane?

Diindolylmethane
  • Estrogen/hormone balance
  • Acne and hormonal skin issues
  • Prostate health support
  • Cancer-risk reduction (unproven)
  • PMS and menopause symptoms
  • General 'detox' support

Diindolylmethane (DIM) is a compound made when your body digests cruciferous vegetables, and it is sold as a supplement mainly for hormone balance and cancer prevention. Although early lab studies look interesting, strong human evidence is lacking for most of these uses. Talk with your pharmacist or doctor before taking DIM, especially if you have a hormone-sensitive condition.

Read the full Diindolylmethane monograph & all interactions
Medication

About Ropinirole

What Is Ropinirole Used For?

Brand names: Requip, Adartrel

Ropinirole tablets are used to treat two conditions: Parkinson's disease and moderate-to-severe primary Restless Legs Syndrome (RLS) — the uncomfortable urge to move the legs, especially at night or at rest.

Ropinirole extended-release tablets are indicated specifically for Parkinson's disease only. If you take the extended-release form, it is not approved for RLS — that use applies to the regular (immediate-release) tablets.

See full Ropinirole drug information
Keep checking

Other Drugs & Diindolylmethane

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

0Major
116Moderate
152Minor
2,561No known interaction
116 Moderate 152 Minor 2,561 No interaction
Moderate

116 interactions

Showing 60 of 116 moderate interactions — see all 116 on the Diindolylmethane page.

Minor

152 interactions

Showing 60 of 152 minor interactions — see all 152 on the Diindolylmethane page.

No interaction 2,561 drugs checked — show the list

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

Showing the 60 most looked-up of 2,561 medications checked with no known interaction — see the full Diindolylmethane list.

See the full Diindolylmethane interactions page
See every supplement checked against Ropinirole, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Diindolylmethane monograph › Uses, safety, and every drug interaction in one place Ropinirole supplement interactions › Every supplement checked against Ropinirole, ranked by severity Ropinirole drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Diindolylmethane and Ropinirole Together: Common Questions

Can you take Diindolylmethane with Ropinirole?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Diindolylmethane and Ropinirole interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Ropinirole and Diindolylmethane?

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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.