Drug & supplement interaction

Cannabichromene (cbc) + Phenobarbital, Phenytoin

Phenobarbital, Phenytoin brand name: Dilantin with PB.

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

Cannabichromene (cbc) has a moderate interaction with Phenobarbital, Phenytoin. Using cannabichromene with drugs that have sedative properties may cause additive therapeutic and adverse effects.

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

Cannabichromene (cbc) and Phenobarbital, Phenytoin

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

Moderate

CNS DEPRESSANTS

Why this applies to Phenobarbital, Phenytoin

Phenobarbital, Phenytoin falls under CNS DEPRESSANTS — the group Cannabichromene (cbc) interacts with.

Using cannabichromene with drugs that have sedative properties may cause additive therapeutic and adverse effects.
Animal research shows that cannabichromene, given as a single dose intraperitoneally, increases the sedative response to the drugs hexobarbital, barbital, and zoxazolamine. However, this effect was not maintained when cannabichromene was given continuously. After receiving cannabichromene daily for 7 days, the sedative effect of these drugs was reduced when compared with a control group or a single dose of cannabichromene.
Severity Moderate Likelihood Possible Evidence D

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.

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

Here's the thing to keep in mind with this combo: phenobarbital is a barbiturate that already calms the nervous system, and CBC may add to that calming effect. In animal studies, a single dose of CBC made barbiturate-type drugs more sedating, so you could feel extra drowsy, foggy, or unsteady, with slower breathing in higher amounts. Interestingly, when CBC was given daily for a week, that boost faded and the sedative effect actually dropped, which could matter for seizure control.

I'll be straight with you: this is based only on lab and animal research, not people, so we can't say how strongly it applies to you. Phenobarbital and phenytoin are tricky drugs where small changes matter, so please check with your pharmacist or doctor before adding any CBC product.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hatoum NS, Davis WM, Waters IW, Elsohly MA, Turner CE. Synergism of cannabichromene and CNS depressants in mice. Gen Pharmacol. 1981;12(5):351-6. 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

Cannabichromene (cbc) Also Interacts With Other Medications

Cannabichromene (cbc) has 247 moderate known drug interactions in our database — the Phenobarbital, Phenytoin one above is one of them. If you take anything else, check it against the full list below.

Moderate 247 No known interaction 2,583 (incl. Phenobarbital, Phenytoin)
Taking anything else?

Check Another of Your Medications Against Cannabichromene (cbc)

Covers the 2,830 medications we’ve checked against Cannabichromene (cbc). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Phenobarbital, Phenytoin

This page covers Cannabichromene (cbc) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenobarbital, Phenytoin page lists 229 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 Kava (major).

By severity: 9 major · 192 moderate · 28 minor.

From our pharmacist’s overview on the Phenobarbital, Phenytoin page

“If your seizure medicine is the phenobarbital and phenytoin combination (Dilantin with PB), read this list carefully before you add any supplement. Nine of the 229 entries rate major, and most of the risk runs through two channels.”

Reviewed by 2 · Jul 18, 2026

Open the Phenobarbital, Phenytoin interaction page

How much people look this up

Where Cannabichromene (cbc) and Phenobarbital, Phenytoin 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 Cannabichromene (cbc)
Steady interest

#1,029 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenobarbital, Phenytoin
Top 25%

#390 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 Cannabichromene (cbc)

What is Cannabichromene (cbc)?

Cannabichromene (cbc)
  • Pain relief
  • Inflammation
  • Mood and anxiety
  • Skin and acne concerns
  • Brain and nerve health

Cannabichromene (CBC) is a non-intoxicating cannabinoid found in the cannabis plant that is being studied for possible pain, anti-inflammatory, and nervous-system effects. Almost all current evidence comes from laboratory and animal research, so we do not yet know how well it works or how safe it is in people. Talk with your pharmacist or doctor before using any CBC product, and avoid it during pregnancy and breastfeeding.

Read the full Cannabichromene (cbc) monograph & all interactions
Keep checking

Other Drugs & Cannabichromene (cbc)

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

0Major
247Moderate
0Minor
2,582No known interaction
247 Moderate 2,582 No interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Cannabichromene (cbc) page.

No interaction 2,582 drugs checked — show the list

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

Showing the 60 most looked-up of 2,582 medications checked with no known interaction — see the full Cannabichromene (cbc) list.

See the full Cannabichromene (cbc) interactions page
See every supplement checked against Phenobarbital, Phenytoin, 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
Cannabichromene (cbc) monograph › Uses, safety, and every drug interaction in one place Phenobarbital, Phenytoin supplement interactions › Every supplement checked against Phenobarbital, Phenytoin, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cannabichromene (cbc) and Phenobarbital, Phenytoin Together: Common Questions

Can you take Cannabichromene (cbc) with Phenobarbital, Phenytoin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Cannabichromene (cbc) and Phenobarbital, Phenytoin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Phenobarbital, Phenytoin and Cannabichromene (cbc)?

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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.