Grapefruit Diet + Peginterferon alfa-2b
Peginterferon alfa-2b brand names: Peg-Intron, ViraferonPeg.
We found no known interaction between Grapefruit Diet and Peginterferon alfa-2b in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.
Grapefruit Diet and Peginterferon alfa-2b
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Peginterferon alfa-2b and Grapefruit Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Grapefruit Diet alongside specific medications may be limited.
Worth understanding: our licensed dataset holds no drug-interaction record for Grapefruit Diet at all — not against Peginterferon alfa-2b, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.
Grapefruit Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
Grapefruit Diet safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
See Every Supplement That Interacts With Peginterferon alfa-2b
This page covers Grapefruit Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Peginterferon alfa-2b page lists 38 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Ashwagandha (moderate) and Black Cohosh (moderate).
By severity: 3 major · 35 moderate.
From our pharmacist’s overview on the Peginterferon alfa-2b page
“Someone taking peginterferon alfa-2b (Peg-Intron) is usually treating hepatitis C, so the liver is already the organ under strain, and all 38 supplement interactions on file for this drug pile additional liver stress on top of it. That earns genuine caution.”
Reviewed by 2 · Jul 18, 2026
Where Grapefruit Diet and Peginterferon alfa-2b 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.
#629 of 1,452 supplements looked up here in the last 7 days
#2,484 of 2,830 medications looked up here in the last 7 days
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.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions. Grapefruit Diet is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Grapefruit Diet reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Grapefruit Diet and Peginterferon alfa-2b records this page draws on were last updated June 22, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About Grapefruit Diet
What is Grapefruit Diet?
- Weight loss
- Appetite control
- Short-term dieting
- Blood sugar support
- General 'detox' plans
The 'Grapefruit Diet' is a fad eating plan that pairs grapefruit or grapefruit juice with low-calorie meals, claiming the fruit burns fat. Any weight loss is most likely from cutting calories rather than a special fat-burning property of grapefruit. Grapefruit interacts with many medications, so talk to your pharmacist or doctor before starting.
Fruit and fruit juice (Citrus paradisi) · Fresh grapefruit, grapefruit juice, and as part of structured low-calorie meal plans; also grapefruit extract capsules sometimes marketed for weight loss
An interaction check asks whether these two react with each other — it does not ask whether Grapefruit Diet is a good idea for someone in your situation. Here is what our Grapefruit Diet record says about it on its own.
Grapefruit Diet: dosing
There is no standardized or medically established dose for the Grapefruit Diet. Plans typically suggest eating half a grapefruit or drinking a small glass of grapefruit juice with meals, but these amounts vary by version and are not based on solid research.If you choose to add grapefruit to your diet, a reasonable, food-based approach is far safer than a strict, very low-calorie plan.
From our Grapefruit Diet monograph — the full record covers uses, side effects and every documented interaction.
About Peginterferon Alfa-2b (PEG-Intron)
What Is Peginterferon Alfa-2b (PEG-Intron) Used For?
Brand names: Peg-Intron, ViraferonPeg
-
Peginterferon alfa-2b is used alone or in combination with ribavirin (a medication) to treat chronic (long-term) hepatitis C infection (swelling of the liver caused by a virus) in people who show signs of liver damage and who have not been treated with interferon alpha (medication similar to peginterferon alfa-2b) in the past. Peginterferon alfa-2b is in a class of medications called interferons. Peginterferon alfa-2b is a combination of interferon and polyethylene glycol, which helps the interferon stay active in your body for a longer period of time. Peginterferon alpha-2b works by decreasing the amount of hepatitis C virus (HCV) in the body. Peginterferon alfa-2b may not cure hepatitis C or prevent you from developing complications of hepatitis C such as cirrhosis (scarring) of the liver, liver failure, or liver cancer. Peginterferon alfa-2b may not prevent the spread of hepatitis C to other people.
Other Drugs & Grapefruit Diet
Browse every other medication we’ve checked against Grapefruit Diet — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Grapefruit Diet against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Ivermectin ›
- Aspirin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Tadalafil ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Valacyclovir ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Ibuprofen ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Bupropion ›
- Lisdexamfetamine ›
- Metformin ›
- Amoxicillin ›
- Acyclovir ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Methotrexate ›
- Fluoxetine ›
- Lamotrigine ›
- Amphetamine ›
- Gabapentin ›
- Pregabalin ›
- Acetaminophen, Codeine ›
- Azithromycin ›
- Dextroamphetamine ›
- Isotretinoin ›
- Clonazepam ›
- Omeprazole ›
- Quetiapine ›
- Methylene Blue ›
- Amlodipine Besylate ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Naproxen ›
- Ciprofloxacin ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Grapefruit Diet list.
Grapefruit Diet References
The 2 sources that drive our Grapefruit Diet monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Grapefruit Diet is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.
- Grapefruit — MedlinePlus Source
- Choosing a Safe and Successful Weight-Loss Program — NIH NIDDK Source
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Following Grapefruit Diet While Taking Peginterferon alfa-2b: Common Questions
Is it safe to follow Grapefruit Diet while taking Peginterferon alfa-2b?
Does Peginterferon alfa-2b interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.