Drug & supplement interaction

Caraway + Hyoscyamine, Phenobarbital

Hyoscyamine, Phenobarbital brand names: Levsin Pb, Levsinex Pb Timecaps.

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

Caraway has a moderate interaction with Hyoscyamine, Phenobarbital. Theoretically, caraway might increase the effects and adverse effects of CNS depressants.

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

Caraway and Hyoscyamine, Phenobarbital

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

Moderate

CNS DEPRESSANTS

Why this applies to Hyoscyamine, Phenobarbital

Hyoscyamine, Phenobarbital falls under CNS DEPRESSANTS — the group Caraway interacts with.

Theoretically, caraway might increase the effects and adverse effects of CNS depressants.
Animal research suggests that (S)-(+)-carvone, a major constituent of caraway seed extract, has sedative effects.
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: your medicine contains phenobarbital, which is a barbiturate that already has a strong calming, sedating effect on the brain. Caraway, on the high-concentration oil or supplement side, may carry its own mild sedative quality. One of its main compounds, carvone, made animals drowsy in lab studies, so on paper the two together could add up to more sleepiness than you'd expect.

What that might look like in real life is extra drowsiness, dizziness, slowed thinking, or feeling unsteady on your feet. I want to be honest though: this is theoretical and based on animal data, not strong human evidence. A pinch of caraway in your cooking is very unlikely to matter. If you're using concentrated caraway oil or capsules, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. de Sousa, D. P., Farias Nobrega, F. F., and de Almeida, R. N. Influence of the chirality of (R)-(-)- and (S)-(+)-carvone in the central nervous system: a comparative study. Chirality 5-5-2007;19(4):264-268.

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

Caraway Also Interacts With Other Medications

Caraway has 407 moderate, 5 minor known drug interactions in our database — the Hyoscyamine, Phenobarbital one above is one of them. If you take anything else, check it against the full list below.

Moderate 407 Minor 5 No known interaction 2,418 (incl. Hyoscyamine, Phenobarbital)
Taking anything else?

Check Another of Your Medications Against Caraway

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

Everything else you take

See Every Supplement That Interacts With Hyoscyamine, Phenobarbital

This page covers Caraway only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hyoscyamine, Phenobarbital page lists 164 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 Henbane (major).

By severity: 10 major · 134 moderate · 20 minor.

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

“The person taking Levsin PB (hyoscyamine with phenobarbital) for gut spasms is often the same person browsing calming herbs and sleep aids, and with this medicine that habit calls for real vigilance. Ten of the 164 supplements on record rate major, and the largest group, 78 ingredients, shares one danger.”

Reviewed by 2 · Jul 18, 2026

Open the Hyoscyamine, Phenobarbital interaction page

One more smart check

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

We hold 191 real supplement products containing Caraway, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Caraway. Your product may carry other ingredients that interact with Hyoscyamine, Phenobarbital too, on top of Caraway — 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 Caraway and Hyoscyamine, Phenobarbital 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 Caraway
Top half

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

29 days ago today
Medication Hyoscyamine, Phenobarbital
Top 25%

#614 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 Caraway

What is Caraway?

Caraway
  • Digestive upset and bloating
  • Gas (flatulence)
  • Indigestion (dyspepsia)
  • Irritable bowel symptoms
  • Increasing breast milk (traditional)

Caraway is a common cooking spice that has long been used to ease gas, bloating, and indigestion. Some evidence suggests caraway oil—often combined with peppermint oil—may help with indigestion, but evidence for most other uses is limited. Food amounts are generally safe; concentrated oils and supplements should be used cautiously and discussed with your pharmacist or doctor.

Read the full Caraway monograph & all interactions
Keep checking

Other Drugs & Caraway

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

0Major
407Moderate
5Minor
2,417No known interaction
407 Moderate 5 Minor 2,417 No interaction
Moderate

407 interactions

Showing 60 of 407 moderate interactions — see all 407 on the Caraway page.

Minor

5 interactions

No interaction 2,417 drugs checked — show the list

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

Showing the 60 most looked-up of 2,417 medications checked with no known interaction — see the full Caraway list.

See the full Caraway interactions page
See every supplement checked against Hyoscyamine, Phenobarbital, 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
Caraway monograph › Uses, safety, and every drug interaction in one place Hyoscyamine, Phenobarbital supplement interactions › Every supplement checked against Hyoscyamine, Phenobarbital, 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 Caraway and Hyoscyamine, Phenobarbital Together: Common Questions

Can you take Caraway with Hyoscyamine, Phenobarbital?
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 Caraway and Hyoscyamine, Phenobarbital 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 Hyoscyamine, Phenobarbital and Caraway?

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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.