Calabash Chalk + Istradefylline
Istradefylline brand name: Nourianz.
We found no known interaction between Calabash Chalk and Istradefylline 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.
Calabash Chalk and Istradefylline
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 Istradefylline and Calabash Chalk 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 Calabash Chalk at all — not against Istradefylline, 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.
Calabash Chalk safety at a glance
Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Calabash Chalk in Pregnancy & Breastfeeding
When calabash chalk is used orally. Calabash chalk contains high levels of lead, arsenic, cadmium, and mercury. Animal data shows that calabash chalk can inhibit uterine implantation, reduce maternal weight gain, and cause fetal changes in the brain, pregnancy resorption, abortion, and stillbirth.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center
See Every Supplement That Interacts With Istradefylline
This page covers Calabash Chalk only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Istradefylline page lists 138 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 · 94 moderate · 41 minor.
From our pharmacist’s overview on the Istradefylline page
“Istradefylline (Nourianz) is added to levodopa to trim the daily 'off' time of Parkinson's disease, and its supplement list deserves genuine care. Most of the 138 ingredients here can change how the liver enzyme CYP3A4 handles the drug, so blood levels may drift too high or too low.”
Reviewed by 2 · Jul 18, 2026
Where Calabash Chalk and Istradefylline 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.
#1,380 of 1,452 supplements looked up here in the last 7 days
#1,095 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 Calabash Chalk reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Calabash Chalk and Istradefylline 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 Calabash Chalk
What is Calabash Chalk?
- Pregnancy cravings and morning sickness
- Easing nausea
- Cultural and traditional eating practice
- Settling the stomach
Calabash chalk is a natural clay-like earth material eaten in some West African and other cultures, often during pregnancy to ease nausea or satisfy cravings. It is not a proven remedy, and testing has repeatedly found it contaminated with lead, arsenic, and other heavy metals, so health authorities warn against eating it. Avoid calabash chalk, especially during pregnancy and breastfeeding.
Natural clay-like mineral material (not a plant) · Solid blocks, molded shapes, lumps, or powder for eating
An interaction check asks whether these two react with each other — it does not ask whether Calabash Chalk is a good idea for someone in your situation. Here is what our Calabash Chalk record says about it on its own.
Calabash Chalk: dosing
There is no safe or recommended dose of calabash chalk. Because it can contain toxic heavy metals, no amount is considered safe to eat.
From our Calabash Chalk monograph — the full record covers uses, side effects and every documented interaction.
About Istradefylline
What Is Istradefylline Used For?
Brand name: Nourianz
Nourianz (istradefylline) is used alongside levodopa/carbidopa in adults with Parkinson's disease. Specifically, it is meant to reduce 'off' episodes — periods when levodopa stops working as well and Parkinson's symptoms return or worsen.
It is an add-on therapy only; it is not used alone or as a replacement for levodopa/carbidopa.
Most-Reported Side Effects for Istradefylline
From FAERS, the FDA’s public side-effect reporting system (5,920 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Calabash Chalk
Browse every other medication we’ve checked against Calabash Chalk — 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 Calabash Chalk 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 ›
- Metoprolol ›
- Rivaroxaban ›
- Aspirin ›
- Acetaminophen ›
- Rosuvastatin ›
- Escitalopram ›
- Abemaciclib ›
- Clopidogrel ›
- Tadalafil ›
- Atorvastatin ›
- Docusate ›
- Valacyclovir ›
- Tirzepatide ›
- Ibuprofen ›
- Methamphetamine ›
- Hydroxyurea ›
- Semaglutide ›
- Warfarin Sodium ›
- Sumatriptan ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Metformin ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Amitriptyline ›
- Methotrexate ›
- Bendamustine ›
- Acyclovir ›
- Doxycycline ›
- Fluoxetine ›
- Amphetamine ›
- Pregabalin ›
- Lamotrigine ›
- Azithromycin ›
- Acetaminophen, Codeine ›
- Isotretinoin ›
- Gabapentin ›
- Dextroamphetamine ›
- Amlodipine Besylate ›
- Methylene Blue ›
- Clonazepam ›
- Omeprazole ›
- Quetiapine ›
- Letrozole ›
- Duloxetine ›
- Naproxen ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Calabash Chalk list.
Calabash Chalk References
The 6 references that drive our Calabash Chalk 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.
- Aprioku JS, Ogwo-Ude EM. Gestational toxicity of calabash chalk (Nzu) in wistar rats. Int J Appl Basic Med Res. 2018;8(4):249-252. PubMed
- Ekanem TB, Ekong MB, Eluwa MA, Igiri AO, Osim EE. Maternal geophagy of calabash chalk on foetal cerebral cortex histomorphology. Malays J Med Sci. 2015;22(4):17-22.
- Reeuwijk NM, Klerx WNM, Kooijman M, Hoogenboom LAP, Rietjens IMCM, Martena MJ. Levels of lead, arsenic, mercury and cadmium in clays for oral use on the Dutch market and estimation of associated risks. Food Addit Contam Part A Chem Anal Control Expo Risk PubMed
- Nutraingredients. FSA issues warning against calabash chalk. UK Food Standards Agency Warning. October 2002. Available at: https://www.nutraingredients.com/Article/2002/10/16/FSA-issues-warning-against-calabash-chalk. Accessed October 23, 2020.
- Food Standards Agency. Importing food supplements and health foods. February 2018. Available at: https://www.food.gov.uk/business-guidance/importing-food-supplements-and-health-foods. Accessed October 23, 2020.
- NYC Health. Calabash chalk containing lead and arsenic. New York City Warning: https://www1.nyc.gov/assets/doh/downloads/pdf/lead/lead-calabash-chalk-faq.pdf. Accessed October 23, 2020.
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 Calabash Chalk and Istradefylline Together: Common Questions
Is it safe to take Calabash Chalk with Istradefylline?
Does Istradefylline interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Keep Exploring
Still Have a Question About Istradefylline and Calabash Chalk?
Our pharmacists answer your medication & supplement questions — free.
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.