Drug & supplement interaction

Weight Watchers Diet + Aprepitant

Aprepitant brand names: Emend, Cinvanti.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Weight Watchers Diet and Aprepitant 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

Weight Watchers Diet and Aprepitant

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 Aprepitant and Weight Watchers Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Weight Watchers Diet alongside specific medications may be limited.

Weight Watchers 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.

Weight Watchers Diet safety at a glance

Weight Watchers Di... overall Use caution Generally safe for most healthy adults, but check with a clinician if you have health conditions or take medications.
Pregnancy Use caution Weight loss is usually not advised during pregnancy; speak with your doctor about appropriate nutrition.
Breastfeeding Use caution Calorie restriction may affect milk supply, so discuss any diet plan with your healthcare provider first.

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

Still wondering about combining Aprepitant and Weight Watchers Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Aprepitant

Interactions in our licensed database are recorded against drug classes, not just single drug names. Aprepitant is filed under 5 classifications — including cytochrome p450 2c9 (cyp2c9) inducers, cytochrome p450 3a4 (cyp3a4) inducers, cytochrome p450 3a4 (cyp3a4) inhibitors. Weight Watchers Diet has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Aprepitant’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Weight Watchers Diet Does Interact With Other Medications

Weight Watchers Diet has 86 moderate known drug interactions in our database — Aprepitant isn’t one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Aprepitant)
Taking anything else?

Check Another of Your Medications Against Weight Watchers Diet

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

What to actually watch for

What Aprepitant’s Own FDA Label Lists

This is not an interaction — none of it involves Weight Watchers Diet. These are the most notable effects listed in the ADVERSE REACTIONS section of Aprepitant’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 Weight Watchers Diet and take the medicine. 10 of them are worth acting on rather than waiting out — marked below.

  • A bowel blockage Worth acting on
  • Dehydration Worth acting on
  • Low sodium Worth acting on
  • Low potassium Worth acting on
  • A slow heartbeat Worth acting on
  • Shortness of breath Worth acting on mentioned in 8.6% of FDA reports for Aprepitant
  • High blood sugar Worth acting on
  • Fainting Worth acting on
  • A severe skin reaction Worth acting on
  • A low platelet count Worth acting on

Showing the 10 most notable of 48 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 Aprepitant. Read the label on DailyMed › Where a percentage is shown, it is the share of 18,355 voluntary FDA FAERS reports for Aprepitant that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Weight Watchers Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Weight Watchers Diet side to compare — that is a limit of the record, not a statement that Weight Watchers Diet has no side effects.

Everything else you take

See Every Supplement That Interacts With Aprepitant

This page covers Weight Watchers Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aprepitant page lists 158 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 116 moderate · 39 minor.

From our pharmacist’s overview on the Aprepitant page

“Aprepitant (Emend, Cinvanti) keeps chemotherapy patients from vomiting, so a supplement that undoes it mid-cycle is a problem, and I read this list with genuine vigilance. Nearly all 158 entries touch CYP3A4, the liver enzyme that clears aprepitant.”

Reviewed by 2 · Jul 18, 2026

Open the Aprepitant interaction page

How much people look this up

Where Weight Watchers Diet and Aprepitant 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 Weight Watchers Diet
Steady interest

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

29 days ago today
Medication Aprepitant
Top 25%

#383 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.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Weight Watchers Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Weight Watchers Diet and Aprepitant 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 .
Eating pattern

About Weight Watchers Diet

What is Weight Watchers Diet?

  • Weight loss
  • Weight maintenance
  • Building healthier eating habits
  • Behavioral support for diet change
  • General wellness and lifestyle improvement

Weight Watchers (now called WW) is a commercial weight-loss program built around a points system, food tracking, and group or online support rather than a pill or herbal product. Research generally shows it can help people lose a modest amount of weight and keep some of it off, especially when combined with regular activity. Talk with your doctor or pharmacist before starting any weight-loss plan, particularly if you have a medical condition.

Not applicable (this is a commercial weight-management program, not a plant or supplement) · Structured eating plan with a points-based food system, app, group or online support, and coaching

An interaction check asks whether these two react with each other — it does not ask whether Weight Watchers Diet is a good idea for someone in your situation. Here is what our Weight Watchers Diet record says about it on its own.

Weight Watchers Diet: dosing

There is no pill or standardized dose for Weight Watchers, since it is a behavioral eating program. Instead, you follow the program's points budget and tracking system as set up in the app or plan you select.The right calorie or points target depends on your age, sex, weight, activity level, and goals, and the program personalizes this for you.

From our Weight Watchers Diet monograph — the full record covers uses, side effects and every documented interaction.

Read the full Weight Watchers Diet monograph & all interactions
Medication

About Aprepitant

What Is Aprepitant Used For?

Brand names: Emend, Cinvanti

Aprepitant is used to prevent nausea and vomiting — not to treat it once it has started. It is always used alongside other anti-nausea medicines, not on its own.

EMEND capsules (oral) are approved for adults and children 12 and older to prevent nausea from highly or moderately emetogenic (nausea-causing) chemotherapy. EMEND for oral suspension extends that same use down to children as young as 6 months. CINVANTI (IV injection) is approved for adults only, for chemotherapy-related nausea. APONVIE (IV emulsion) is approved for adults to prevent postoperative nausea and vomiting (PONV) — nausea after surgery. Aprepitant capsules (generic) are approved for adults and children 12 and older for chemotherapy-related nausea, and also for adults to prevent PONV.

Most-Reported Side Effects for Aprepitant

From FAERS, the FDA’s public side-effect reporting system (18,355 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Nausea 2,245 reports
Fatigue 1,943 reports
Fever 1,653 reports
Diarrhea 1,604 reports
Dyspnea 1,583 reports
See full Aprepitant drug information
Keep checking

Other Drugs & Weight Watchers Diet

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Weight Watchers Diet page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Weight Watchers Diet list.

See the full Weight Watchers Diet interactions page
See every supplement checked against Aprepitant, ranked by severity
Evidence & sources

Weight Watchers Diet References

The 1 references that drive our Weight Watchers Diet monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. O'Neil PM, Miller-Kovach K, Tuerk PW, et al. Randomized controlled trial of a nationally available weight control program tailored for adults with type 2 diabetes. Obesity (Silver Spring). 2016;24(11):2269-2277. PubMed

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 Weight Watchers Diet While Taking Aprepitant: Common Questions

Is it safe to follow Weight Watchers Diet while taking Aprepitant?
We do not list a known interaction between Weight Watchers Diet and Aprepitant. 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.
How was the Weight Watchers Diet and Aprepitant combination checked?
Interactions in our licensed database are recorded against drug classes. Aprepitant is filed under 5 classifications, and Weight Watchers Diet has documented interactions with 1 drug class — none of Aprepitant's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Weight Watchers Diet interact with any other medications?
Yes. Weight Watchers Diet has 86 documented drug interactions in our database — Aprepitant is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Aprepitant interact with any supplements?
Yes. Aprepitant has documented interactions with 158 supplements in our database — Weight Watchers Diet is not one of them. The Aprepitant 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

Weight Watchers Diet monograph Uses, safety profile, and every drug interaction in one place Aprepitant drug information The full plain-English guide to this medication Aprepitant supplement interactions Every supplement checked against Aprepitant, 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Aprepitant and Weight Watchers 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.