Drug & supplement interaction

Diindolylmethane + Propranolol

Propranolol brand names: Inderal LA, Inderal, Angilol, Syprol, Inderal Injection, and others.

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

Diindolylmethane has a minor interaction with Propranolol. 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 Propranolol

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

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Propranolol

Propranolol 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 propranolol, and lab studies hint that DIM may rev up that enzyme. If that happened in real life, your body could clear propranolol a little faster, meaning slightly lower levels and possibly a weaker effect. For propranolol that could look like blood pressure or heart rate creeping back up, more migraines, or returning tremor or chest pain.

That said, I want to keep this in perspective. This is only a theoretical concern from test-tube research, and it has never actually been reported in people. It's rated minor and unlikely. Still, if you take propranolol for something important and want to try DIM, check with your pharmacist or doctor first and keep an eye on your numbers.

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 Propranolol 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. Propranolol)
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 Propranolol

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 Propranolol, 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 Propranolol

This page covers Diindolylmethane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Propranolol page lists 236 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Indian Snakeroot (major) and Tyramine (major).

By severity: 5 major · 194 moderate · 37 minor.

From our pharmacist’s overview on the Propranolol page

“Propranolol (Inderal) slows the heart and lowers blood pressure, which is exactly why its 236-ingredient interaction list deserves genuine care. Five entries rate major, and those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Propranolol 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 Propranolol 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 Propranolol 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 Propranolol
Top 1%

#11 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 Propranolol (Cardiovascular)

What Is Propranolol (Cardiovascular) Used For?

Brand names: Inderal LA, Inderal, Angilol, Syprol, Inderal Injection, Half-Inderal LA, Bedranol SR, Half Beta Prograne, Beta Prograne, Lopranol LA, Slo-Pro, InnoPran XL

This intravenous (IV) form of propranolol is used in hospital or clinical settings to treat dangerous heart rhythm problems. It is generally reserved for life-threatening arrhythmias (abnormal heart rhythms) or those that occur during anesthesia.

Specific conditions it treats include fast heart rates coming from the upper chambers of the heart (supraventricular tachycardia), certain arrhythmias caused by digitalis toxicity, dangerous ventricular rhythms that haven't responded to other treatments, and fast heart rates caused by excess adrenaline-like substances during surgery.

See full Propranolol (Cardiovascular) 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 Propranolol, 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 Propranolol supplement interactions › Every supplement checked against Propranolol, ranked by severity Propranolol (Cardiovascular) 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 Propranolol Together: Common Questions

Can you take Diindolylmethane with Propranolol?
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 Propranolol 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 Propranolol 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.