Drug & supplement interaction

Calabash Chalk + Ospemifene

Ospemifene brand name: Osphena.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Calabash Chalk and Ospemifene 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 Ospemifene states a food rule worth keeping to.

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Interaction report

Calabash Chalk and Ospemifene

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 Ospemifene 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 Ospemifene, 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

Calabash Chalk overall Avoid It is often contaminated with lead, arsenic, and other heavy metals and is not safe to eat.
Pregnancy Likely Unsafe When calabash chalk is used orally. Calabash chalk contains high levels of lead, arsenic, cadmium, and mercury. Animal data shows that calabash chalk can inhibi... Read the full pregnancy detail
Breastfeeding Likely Unsafe When calabash chalk is used orally. Calabash chalk contains high levels of lead, arsenic, cadmium, and mercury. Animal data shows that calabash chalk can inhibi... Read the full breastfeeding detail

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.

Still wondering about combining Ospemifene and Calabash Chalk? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Ospemifene’s Own FDA Label Lists

This is not an interaction — none of it involves Calabash Chalk. These are the most notable effects listed in the ADVERSE REACTIONS section of Ospemifene’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 take both. 6 of them are worth acting on rather than waiting out — marked below.

  • A stroke or mini-stroke Worth acting on
  • Blood clots Worth acting on
  • Bleeding or bruising Worth acting on mentioned in 5.8% of FDA reports for Ospemifene
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on
  • An allergic reaction Worth acting on
  • Flushing mentioned in 14.3% of FDA reports for Ospemifene
  • Muscle pain mentioned in 7.5% of FDA reports for Ospemifene
  • Sweating
  • Itching

Showing the 10 most notable of 12 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 Ospemifene. Read the label on DailyMed › Where a percentage is shown, it is the share of 2,601 voluntary FDA FAERS reports for Ospemifene that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Calabash Chalk’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Calabash Chalk side to compare — that is a limit of the record, not a statement that Calabash Chalk has no side effects.

Special populations

Calabash Chalk in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

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

How to take them

Some Ospemifene Products Have a Food Rule — Calabash Chalk Should Not Break It

At least one FDA label for a product containing Ospemifene says to take it with food. If you take Calabash Chalk on an empty stomach out of habit, keep them separate — and take Ospemifene with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Ospemifene 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.

One tablet taken orally once daily with food.

From the Dosage and Administration section of the FDA label we read for Ospemifene — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

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.

Everything else you take

See Every Supplement That Interacts With Ospemifene

This page covers Calabash Chalk only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ospemifene page lists 155 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), Tiratricol (major) and Acacia Rigidula (moderate).

By severity: 4 major · 112 moderate · 39 minor.

From our pharmacist’s overview on the Ospemifene page

“Women prescribed ospemifene (Osphena) for painful intercourse after menopause are often the same women reaching for St. John's wort for mood or grapefruit juice at breakfast, and both sit among the four major-rated interactions on this page, so the list deserves genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Ospemifene interaction page

How much people look this up

Where Calabash Chalk and Ospemifene 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 Calabash Chalk
Steady interest

#1,347 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ospemifene
Steady interest

#2,474 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 Calabash Chalk reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Calabash Chalk and Ospemifene 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.
Data structure & sourcing designed and verified by .
Supplement

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.

Read the full Calabash Chalk monograph & all interactions
Medication

About Ospemifene

What Is Ospemifene Used For?

Brand name: Osphena

Osphena (ospemifene) is used to treat two specific symptoms of vulvar and vaginal atrophy — the thinning and drying of vaginal tissues that can happen after menopause. The first is moderate to severe dyspareunia (painful intercourse), and the second is moderate to severe vaginal dryness.

Both of these uses are for postmenopausal women only. Osphena is not used in children or in women who are pregnant or may become pregnant.

Most-Reported Side Effects for Ospemifene

From FAERS, the FDA’s public side-effect reporting system (2,601 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Hot flush 372 reports
Headache 209 reports
Muscle spasms 194 reports
Vaginal haemorrhage 150 reports
Vaginal discharge 134 reports
See full Ospemifene drug information
Keep checking

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.

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

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.

  1. 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
  2. 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.
  3. 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
  4. 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.
  5. 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.
  6. 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.

Pharmacist Counseling Corner

Taking Calabash Chalk and Ospemifene Together: Common Questions

Is it safe to take Calabash Chalk with Ospemifene?
We do not list a known interaction between Calabash Chalk and Ospemifene. 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.
Should I take Calabash Chalk and Ospemifene at the same time of day?
At least one FDA label for a product containing Ospemifene says to take it with food. If you take Calabash Chalk on an empty stomach out of habit, keep them separate and take Ospemifene with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Ospemifene products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Ospemifene interact with any supplements?
Yes. Ospemifene has documented interactions with 155 supplements in our database — Calabash Chalk is not one of them. The Ospemifene 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 Ospemifene and Calabash Chalk?

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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.