Shellac + Methylnaltrexone
Methylnaltrexone brand name: Relistor.
We found no known interaction between Shellac and Methylnaltrexone 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. Additionally, although there is no interaction, the label for Methylnaltrexone states a food rule worth keeping to.
Shellac and Methylnaltrexone
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 Methylnaltrexone and Shellac in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
Worth understanding: our licensed dataset holds no drug-interaction record for Shellac at all — not against Methylnaltrexone, 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.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. 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.
Shellac safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Some Methylnaltrexone Products Have a Food Rule — Shellac Should Not Break It
At least one FDA label for a product containing Methylnaltrexone says to take it on an empty stomach. Most supplements — Shellac included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Methylnaltrexone on its own and move Shellac to a meal later in the day.
This may not be true of your version. Food instructions belong to the product, not the ingredient: two Methylnaltrexone products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.
o In patients with chronic non-cancer pain and OIC, take RELISTOR tablets with water on an empty stomach at least 30 minutes before the first meal of the day.
From the Dosage and Administration section of the FDA label we read for Methylnaltrexone — where that label names a specific product, the instruction is that product's. See the Methylnaltrexone drug page ›
A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.
See Every Supplement That Interacts With Methylnaltrexone
This page covers Shellac only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylnaltrexone page lists 3 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Fever Bark (moderate), Iboga (moderate) and Yohimbe (moderate).
By severity: 3 moderate.
From our pharmacist’s overview on the Methylnaltrexone page
“If you take methylnaltrexone (Relistor) for opioid-induced constipation, the supplement list to know is short: three ingredients, all rated moderate, none major. Yohimbe, fever bark, and iboga are all cleared by the same liver enzyme, CYP2D6, and methylnaltrexone can slow that enzyme, letting their active compounds build up in your blood.”
Reviewed by 2 · Jul 18, 2026
Where Shellac and Methylnaltrexone 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.
#723 of 1,452 supplements looked up here in the last 7 days
#2,565 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.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Shellac reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Shellac and Methylnaltrexone records this page draws on were last updated July 10, 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 Shellac
What is Shellac?
- Coating for tablets and capsules
- Glaze on candy and chocolates
- Protective film over pills and supplements
- Enteric-style coating to delay dissolving
- Shiny coating on fruits and confections
Shellac is a natural resin made from the secretions of the lac insect, and it is used mainly as a glaze or coating on pills, candy, and some supplements rather than as an active ingredient you take for a health benefit. In the small amounts used for coatings it is generally considered safe for most people, but those avoiding insect-derived products or with known sensitivities may want to steer clear.
Resinous secretion of the lac insect (Kerria lacca) · Tablet and capsule coatings, candy and pill glazes, food glaze (confectioner's glaze)
An interaction check asks whether these two react with each other — it does not ask whether Shellac is a good idea for someone in your situation. Here is what our Shellac record says about it on its own.
Shellac: dosing
There is no established therapeutic dose for shellac, because it is not taken as an active ingredient. It is used in whatever small amount is needed to coat or glaze a product.If you are choosing a supplement, you do not need to dose shellac itself.
From our Shellac monograph — the full record covers uses, side effects and every documented interaction.
About Methylnaltrexone
What Is Methylnaltrexone Used For?
Brand name: Relistor
Methylnaltrexone, sold as Relistor, treats opioid-induced constipation (OIC) — constipation caused by opioid pain medications. Both Relistor tablets and Relistor injection are approved for adults with chronic non-cancer pain, including those with pain related to a prior cancer or its treatment who do not need frequent opioid dose increases.
Relistor injection is also approved for adults with advanced illness or active cancer pain who require increasing opioid doses as part of palliative care.
Other Drugs & Shellac
Browse every other medication we’ve checked against Shellac — 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 Shellac 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 ›
- Ivermectin ›
- Abemaciclib ›
- Aspirin ›
- Acetaminophen ›
- Metoprolol ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Tadalafil ›
- Docusate ›
- Tirzepatide ›
- Ibuprofen ›
- Methamphetamine ›
- Hydroxyurea ›
- Warfarin Sodium ›
- Valacyclovir ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Lisdexamfetamine ›
- Propranolol ›
- Metformin ›
- Amitriptyline ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Amlodipine Besylate ›
- Methotrexate ›
- Bendamustine ›
- Bupropion ›
- Amphetamine ›
- Doxycycline ›
- Fluoxetine ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Quetiapine ›
- Clonazepam ›
- Levothyroxine, Liothyronine ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Methylene Blue ›
- Duloxetine ›
- Buspirone ›
- Citalopram ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Shellac list.
Shellac References
The 8 references that drive our Shellac 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.
- The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
- González-Villanueva I, Hispn Ocete P, Silvestre Salvador JF. Allergic contact dermatitis caused by a black tattoo ink in a patient allergic to shellac. Contact Dermatitis. 2016;75(4):247-8. PubMed
- Shaw T, Oostman H, Rainey D, Storrs F. A rare eyelid dermatitis allergen: shellac in a popular mascara. Dermatitis. 2009;20(6):341-5. DOI
- Gallo R, Marro I, Pavesi A. Allergic contact dermatitis from shellac in mascara. Contact Dermatitis. 2005;53(4):238. PubMed
- Strauss RM, Orton DI. Allergic contact cheilitis in the United Kingdom: a retrospective study. Am J Contact Dermat. 2003;14(2):75-7. DOI
- Orton DI, Salim A, Shaw S. Allergic contact cheilitis due to shellac. Contact Dermatitis. 2001;44(4):250. PubMed
- Navarro-Triviño FJ. Allergic contact dermatitis from shellac in an ecological hair spray occurring in a patient with frontal fibrosing alopecia. Contact Dermatitis 2022;86(6):544-545. PubMed
- Mercader-García P, Ruiz-Gonzalez I, Gonzalez-Perez R, Sanz-Sanchez T, Sanchez-Pérez J, Borrego L; en representación de REIDAC. Contact Allergy to Shellac. Retrospective Cross-Sectional Study With Data From the Spanish Registry of Research in Contact Derma
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.
Taking Shellac and Methylnaltrexone Together: Common Questions
Is it safe to take Shellac with Methylnaltrexone?
Should I take Shellac and Methylnaltrexone at the same time of day?
Does Methylnaltrexone 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.