Orlistat and Vitamin E: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 9, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Orlistat
Vitamin E
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced vitamin E efficacy
Interaction Deep Dive
A pharmacokinetic interaction study showed orlistat inhibited absorption of a vitamin E acetate supplement by approximately 60%. Encourage patients strongly to take a multivitamin supplement that contains fat-soluble vitamins to ensure adequate nutrition because orlistat has been shown to reduce the absorption of some fat-soluble vitamins. Take the supplement once a day at least 2 hours before or after the administration of orlistat, such as at bedtime1.
Why it happens (mechanism)
Reduced absorption of vitamin E by orlistat
Literature reports
1 report — tap to read
a) A pharmacokinetic interaction study showed orlistat inhibited absorption of a vitamin E acetate supplement by approximately 60% 1.
Common questions
Can I take Orlistat and Vitamin E together?
Reduced vitamin E efficacy Always confirm with your pharmacist or prescriber before making any change.
How serious is the Orlistat and Vitamin E interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Orlistat or Vitamin E need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: XENICAL oral capsules, orlistat oral capsules. H2-Pharma, LLC (per Dailymed), Montgomery, AL, 2023. DailyMed
Keep reading about Orlistat
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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