Drug & supplement interaction

Feingold Diet + Selpercatinib

Selpercatinib brand name: Retevmo.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Feingold Diet and Selpercatinib 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

Feingold Diet and Selpercatinib

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

Worth understanding: our licensed dataset holds no drug-interaction record for Feingold Diet at all — not against Selpercatinib, 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.

Feingold 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.

Feingold Diet safety at a glance

Feingold Diet overall Use caution Generally low risk, but restrictive diets in children can lead to nutrition gaps if not supervised.
Pregnancy Use caution The diet is aimed at children; pregnant people should not follow restrictive diets without medical guidance.
Breastfeeding Use caution Restricting your own diet while breastfeeding is not recommended without a clinician's advice.

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

Still wondering about combining Selpercatinib and Feingold Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Selpercatinib’s Own FDA Label Lists

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

  • A change in thyroid levels Worth acting on
  • A stroke or mini-stroke Worth acting on
  • Bone thinning Worth acting on
  • Low sodium Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • Heart failure Worth acting on
  • Fainting Worth acting on
  • An irregular heartbeat Worth acting on
  • Raised blood pressure Worth acting on mentioned in 5.3% of FDA reports for Selpercatinib
  • Chest pain Worth acting on

Showing the 10 most notable of 44 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 Selpercatinib. Read the label on DailyMed › Where a percentage is shown, it is the share of 1,250 voluntary FDA FAERS reports for Selpercatinib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Feingold Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Feingold Diet side to compare — that is a limit of the record, not a statement that Feingold Diet has no side effects.

Everything else you take

See Every Supplement That Interacts With Selpercatinib

This page covers Feingold Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selpercatinib page lists 178 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 132 moderate · 35 minor.

From our pharmacist’s overview on the Selpercatinib page

“People facing a RET-driven lung or thyroid cancer often add supplements for strength, sleep, or immune support, and with selpercatinib (Retevmo) that instinct needs a careful check. Eleven of the 178 ingredients here carry a major rating, and the largest cluster affects how the drug is cleared by the CYP3A4 enzyme: St.”

Reviewed by 2 · Jul 18, 2026

Open the Selpercatinib interaction page

How much people look this up

Where Feingold Diet and Selpercatinib 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 Feingold Diet
Steady interest

#1,092 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Selpercatinib
Top 25%

#294 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 Feingold Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Feingold Diet and Selpercatinib records this page draws on were last updated July 11, 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 Feingold Diet

What is Feingold Diet?

  • Hyperactivity (ADHD) in children
  • Behavioral problems in kids
  • Attention and focus concerns
  • Childhood sleep and mood issues

The Feingold Diet is an elimination eating plan that removes certain artificial food colors, flavors, sweeteners, preservatives, and some natural salicylate-containing foods, mainly to reduce hyperactivity in children. Scientific evidence is mixed and limited, though a small number of children may be sensitive to specific food additives. If you try it, work with a pediatrician or registered dietitian so your child still gets balanced nutrition.

Elimination diet / structured eating plan

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

Feingold Diet: dosing

There is no pill or standardized "dose" for the Feingold Diet — it is a pattern of eating. It is typically done in phases: a stricter starting period that removes targeted additives and salicylate-rich foods, followed by gradual reintroduction to identify specific triggers.Because the diet can be complex and restrictive, it is best to follow program guidance and work with a registered dietitian or pediatrician to make sure your child's overall diet stays balanced.

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

Read the full Feingold Diet monograph & all interactions
Medication

About Selpercatinib

What Is Selpercatinib Used For?

Brand name: Retevmo

Selpercatinib treats cancers driven by changes in the RET gene — either a gene fusion (where RET joins abnormally with another gene) or a RET mutation (a change in the gene itself). Your doctor will confirm one of these changes with an FDA-approved test before prescribing it.

It is approved for adults with RET fusion-positive non-small cell lung cancer; adults and children 2 and older with RET-mutant medullary thyroid cancer or RET fusion-positive thyroid cancer; and adults and children 2 and older with other advanced solid tumors that have a RET gene fusion and have not responded to prior treatment.

See full Selpercatinib drug information
Keep checking

Other Drugs & Feingold Diet

Browse every other medication we’ve checked against Feingold 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Feingold Diet References

The 2 references that drive our Feingold 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. Conners CK, Goyette CH, Southwick DA, et al. Food additives and hyperkinesis: a controlled double-blind experiment. Pediatrics 1976;58:154-66. DOI
  2. Harley JP, Ray RS, Tomasi L, et al. Hyperkinesis and food additives: testing the Feingold hypothesis. Pediatrics 1978;61:818-28. DOI

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 Feingold Diet While Taking Selpercatinib: Common Questions

Is it safe to follow Feingold Diet while taking Selpercatinib?
We do not list a known interaction between Feingold Diet and Selpercatinib. 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 Selpercatinib interact with any supplements?
Yes. Selpercatinib has documented interactions with 178 supplements in our database — Feingold Diet is not one of them. The Selpercatinib interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Selpercatinib and Feingold 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.