Drug & supplement interaction

Borage + Chlorpromazine

Chlorpromazine brand names: Thorazine, Thorazine Spansules.

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

Borage has a moderate interaction with Chlorpromazine. Theoretically, taking borage sed oil with phenothiazines might increase the risk of seizures.

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

Borage and Chlorpromazine

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

Moderate

PHENOTHIAZINES

Why this applies to Chlorpromazine

Chlorpromazine falls under PHENOTHIAZINES — the group Borage interacts with.

Theoretically, taking borage sed oil with phenothiazines might increase the risk of seizures.
Borage seed oil contains gamma-linolenic acid (GLA). There is concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines. This is based on limited data from two reports published in the 1980s. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with evening primrose, another source of GLA. However, none experienced an actual seizure. In the other report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose 4 grams daily was added. One of these patients had a prior history of seizures. It is unclear whether evening primrose had any additive epileptogenic effects with the phenothiazines, but there is no evidence that taking GLA-containing supplements alone can cause seizures.
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 concern with pairing borage seed oil and chlorpromazine (Thorazine). Chlorpromazine on its own can already lower the seizure threshold a bit, meaning it can make seizures slightly more likely in some people. Borage is rich in an omega-6 fat called GLA, and the worry is that adding it on top might nudge that seizure risk a little higher.

I want to be honest about how thin this evidence is. It comes from a couple of small reports in the 1980s involving a different GLA source (evening primrose), not borage itself, and one of those patients already had a seizure history. So this is theoretical rather than proven. Still, since seizures are serious, please check with your pharmacist or doctor before starting borage, and choose a 'PA-free' product.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Holman CP and Bell AF. A trial of evening primrose oil in the treatment of chronic schizophrenia. J Orhtomolecular Psych 1983;12:302-304.
  2. Vaddadi KS. The use of gamma-linolenic acid and linoleic acid to differentiate between temporal lobe epilepsy and schizophrenia. Prostaglandins Med 1981;6(4):375-379. PubMed
  3. Puri BK. The safety of evening primrose oil in epilepsy. Prostaglandins Leukotrienes Essential Fatty Acids 2007;77:101-3. 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

Borage Also Interacts With Other Medications

Borage has 225 moderate known drug interactions in our database — the Chlorpromazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 225 No known interaction 2,605 (incl. Chlorpromazine)
Taking anything else?

Check Another of Your Medications Against Borage

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

From our Q&A

Questions About Borage or Chlorpromazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Borage or Chlorpromazine, 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 Chlorpromazine

This page covers Borage only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorpromazine page lists 211 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), American Hellebore (major), Arsenic (major) and Beer (major).

By severity: 17 major · 159 moderate · 35 minor.

Open the Chlorpromazine interaction page

One more smart check

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

We hold 122 real supplement products containing Borage, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Borage. Your product may carry other ingredients that interact with Chlorpromazine too, on top of Borage — 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 Borage and Chlorpromazine 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 Borage
Top 25%

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

29 days ago today
Medication Chlorpromazine
Steady interest

#1,842 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 Borage

What is Borage?

Borage
  • Eczema and dry skin
  • Rheumatoid arthritis
  • Inflammation
  • Respiratory complaints
  • Mood and stress

Borage is a Mediterranean herb whose seed oil is rich in gamma-linolenic acid (GLA), an omega-6 fatty acid studied mostly for skin conditions and arthritis with mixed results. The plant's leaves and flowers can contain liver-toxic pyrrolizidine alkaloids, so only use products clearly labeled 'PA-free' and talk to your pharmacist or doctor before taking it.

Read the full Borage monograph & all interactions
Medication

About Chlorpromazine

What Is Chlorpromazine Used For?

Brand names: Thorazine, Thorazine Spansules

Chlorpromazine is used to manage psychotic disorders and treat schizophrenia. It also controls nausea and vomiting, relieves restlessness and apprehension before surgery, and controls the manic phase of manic-depressive illness. Other uses include relief of intractable hiccups, treatment of acute intermittent porphyria, and use as an adjunct in tetanus treatment.

In children ages 1 to 12, it is used for severe behavioral problems marked by explosive or combative behavior, and for short-term treatment of hyperactive children with conduct disorders. The oral forms are also approved for the management of manifestations of psychotic disorders broadly, in addition to the uses shared with the injection form.

See full Chlorpromazine drug information
Keep checking

Other Drugs & Borage

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

0Major
225Moderate
0Minor
2,604No known interaction
225 Moderate 2,604 No interaction
Moderate

225 interactions

Showing 60 of 225 moderate interactions — see all 225 on the Borage page.

No interaction 2,604 drugs checked — show the list

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

Showing the 60 most looked-up of 2,604 medications checked with no known interaction — see the full Borage list.

See the full Borage interactions page
See every supplement checked against Chlorpromazine, 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
Borage monograph › Uses, safety, and every drug interaction in one place Chlorpromazine supplement interactions › Every supplement checked against Chlorpromazine, ranked by severity Chlorpromazine 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 Borage and Chlorpromazine Together: Common Questions

Can you take Borage with Chlorpromazine?
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 Borage and Chlorpromazine 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 Chlorpromazine and Borage?

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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.