Drug & supplement interaction

Grapefruit Diet + Formoterol

Formoterol brand names: Foradil Aerolizer, Atimos Modulite, Oxis Turbohaler, Perforomist, Foradil Certihaler.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated June 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Grapefruit Diet and Formoterol 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.

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Interaction report

Grapefruit Diet and Formoterol

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 Formoterol 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 Formoterol, 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

Grapefruit Diet overall Use caution Grapefruit is a healthy food, but very low-calorie versions of this diet can be hard to sustain and grapefruit affects many medications.

Pregnancy Use caution Eating grapefruit as food is generally fine, but very low-calorie diets should be avoided during pregnancy.

Breastfeeding Use caution Grapefruit as food is usually fine, but restrictive dieting while breastfeeding is not recommended.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Formoterol and Grapefruit Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

What to actually watch for

What Formoterol’s Own FDA Label Lists

This is not an interaction — none of it involves Grapefruit Diet. These are the most notable effects listed in the ADVERSE REACTIONS section of Formoterol’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you follow Grapefruit Diet and take the medicine. 7 of them are worth acting on rather than waiting out — marked below.

Low potassium Worth acting on
High blood sugar Worth acting on
Wheezing Worth acting on
Chest pain Worth acting on
Raised blood pressure Worth acting on
A severe allergic reaction Worth acting on
Hives Worth acting on
Tremor or shakiness
Dry mouth
A fast or pounding heartbeat

Showing the 10 most notable of 22 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Formoterol. Read the label on DailyMed › Grapefruit Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Grapefruit Diet side to compare — that is a limit of the record, not a statement that Grapefruit Diet has no side effects.

Everything else you take

See Every Supplement That Interacts With Formoterol

This page covers Grapefruit Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Formoterol page lists 103 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,3-dmaa (moderate), Acacia Rigidula (moderate), Active Hexose Correlated Compound (ahcc) (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 84 moderate · 19 minor.

From our pharmacist’s overview on the Formoterol page

“Formoterol (Foradil, Perforomist) is the long-acting half of many asthma and COPD inhalers, keeping airways open for hours, and its supplement list is calmer than its length suggests. None of the 103 ingredients on file is rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Formoterol interaction page

How much people look this up

Where Grapefruit Diet and Formoterol 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 Grapefruit Diet

Steady interest

#1,130 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Formoterol

Steady interest

#2,502 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.

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 20, 2026. The Grapefruit Diet and Formoterol 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.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Eating pattern

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.

Read the full Grapefruit Diet monograph & all interactions

Medication

About Formoterol Oral Inhalation

What Is Formoterol Oral Inhalation Used For?

Brand names: Foradil Aerolizer, Atimos Modulite, Oxis Turbohaler, Perforomist, Foradil Certihaler

Formoterol fumarate inhalation solution is used for the long-term maintenance treatment of airway narrowing (bronchoconstriction) in adults with COPD, including chronic bronchitis and emphysema. It is taken twice daily — morning and evening — as a regular, ongoing treatment.

Important limits: This medication is not for relieving sudden COPD flare-ups or breathlessness in the moment, and it is not approved to treat asthma. A separate short-acting inhaler should always be on hand for sudden symptoms.

See full Formoterol Oral Inhalation drug information

Keep checking

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.

0Major

0Moderate

0Minor

2,829No known interaction

2,829 No interaction

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.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Grapefruit Diet list.

See the full Grapefruit Diet interactions page

See every supplement checked against Formoterol, ranked by severity

Evidence & sources

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.

Pharmacist Counseling Corner

Following Grapefruit Diet While Taking Formoterol: Common Questions

Is it safe to follow Grapefruit Diet while taking Formoterol?

We do not list a known interaction between Grapefruit Diet and Formoterol. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Does Formoterol interact with any supplements?

Yes. Formoterol has documented interactions with 103 supplements in our database — Grapefruit Diet is not one of them. The Formoterol interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Grapefruit Diet monograph Uses, safety profile, and every drug interaction in one place Formoterol Oral Inhalation drug information The full plain-English guide to this medication Formoterol supplement interactions Every supplement checked against Formoterol, 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 References The 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Formoterol and Grapefruit Diet?

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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.