Drug & supplement interaction

Diindolylmethane + Ramelteon

Ramelteon brand name: Rozerem.

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

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

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Diindolylmethane and Ramelteon

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

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Ramelteon

Ramelteon 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 break down ramelteon. In lab studies (test tube only, not people), DIM appears to speed up that enzyme. If that happened in your body, ramelteon could be cleared a little faster and not build up as much, which in theory might make it a touch less effective at helping you drift off to sleep.

I want to be honest with you though: this is purely theoretical. It has never actually been reported in humans, and it's rated as a minor, unlikely interaction. Ramelteon isn't a prodrug, so this isn't a safety concern, just a possible drop in benefit. If you take both and notice your sleep slipping, mention it to your pharmacist or doctor.

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 Ramelteon 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. Ramelteon)
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 Ramelteon

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 Ramelteon, 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 Ramelteon

This page covers Diindolylmethane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ramelteon page lists 228 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Grapefruit (major).

By severity: 9 major · 173 moderate · 46 minor.

From our pharmacist’s overview on the Ramelteon page

“Ramelteon (Rozerem) is a prescription sleep aid, and its 228 interacting supplements call for real care, starting with the nine rated major. The frustrating part is that the things sleepless people typically reach for, kava, CBD, a glass of wine before bed, sit at the heart of the problem.”

Reviewed by 2 · Jul 18, 2026

Open the Ramelteon 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 Ramelteon 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 Ramelteon 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 Ramelteon
Top half

#1,193 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 Ramelteon

What Is Ramelteon Used For?

Brand name: Rozerem

Ramelteon tablets — sold as the brand Rozerem and as generic ramelteon — are used to treat insomnia when the main problem is trouble falling asleep at the start of the night. It is not indicated for difficulty staying asleep.

Clinical studies supporting its effectiveness ran up to six months in both adults and elderly patients.

See full Ramelteon 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 Ramelteon, 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 Ramelteon supplement interactions › Every supplement checked against Ramelteon, ranked by severity Ramelteon 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 Ramelteon Together: Common Questions

Can you take Diindolylmethane with Ramelteon?
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 Ramelteon 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 Ramelteon and Diindolylmethane?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.