Drug & supplement interaction

Gras + Lanthanum Carbonate

Lanthanum Carbonate brand name: Fosrenol.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Gras and Lanthanum Carbonate 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 Lanthanum Carbonate states a food rule worth keeping to.

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Interaction report

Gras and Lanthanum Carbonate

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 Lanthanum Carbonate and Gras 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 Gras at all — not against Lanthanum Carbonate, 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.

Gras safety at a glance

Gras overall Not established We cannot confirm what "Gras" is, so its safety is unknown.
Pregnancy Avoid Because the product is unidentified, avoid it during pregnancy unless a doctor confirms it is safe.
Breastfeeding Avoid With no reliable information, avoid it while breastfeeding unless cleared by your doctor.

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

Still wondering about combining Lanthanum Carbonate and Gras? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Lanthanum Carbonate’s Own FDA Label Lists

This is not an interaction — none of it involves Gras. These are the most notable effects listed in the ADVERSE REACTIONS section of Lanthanum Carbonate’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. One of them is worth acting on rather than waiting out — marked below.

  • A bowel blockage Worth acting on
  • Stomach upset
  • Constipation
  • Stomach pain
  • Diarrhea
  • Vomiting
  • Nausea

From the ADVERSE REACTIONS section of the FDA label for Lanthanum Carbonate. Read the label on DailyMed › Gras’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Gras side to compare — that is a limit of the record, not a statement that Gras has no side effects.

How to take them

Some Lanthanum Carbonate Products Have a Food Rule — Gras Should Not Break It

At least one FDA label for a product containing Lanthanum Carbonate says to take it with food. If you take Gras on an empty stomach out of habit, keep them separate — and take Lanthanum Carbonate 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 Lanthanum Carbonate 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.

Do not store FOSRENOL Oral Powder for future use once mixed with food.

From the Dosage and Administration section of the FDA label we read for Lanthanum Carbonate — 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 Lanthanum Carbonate

This page covers Gras only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lanthanum Carbonate page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

Open the Lanthanum Carbonate interaction page

How much people look this up

Where Gras and Lanthanum Carbonate 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 Gras
Steady interest

#1,023 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Lanthanum Carbonate
Steady interest

#2,034 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. Gras is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Gras reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Gras and Lanthanum Carbonate records this page draws on were last updated June 20, 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 Gras

What is Gras?

We could not find reliable information about a dietary supplement or herb called "Gras." The name may be a misspelling, a brand name, or a local/regional term, so we cannot confirm what it is, what it does, or whether it is safe. Please double-check the name with your pharmacist or the product label before using it.

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

Gras: dosing

There is no established or recommended dose for "Gras" because the product cannot be reliably identified. We will not guess an amount. If you have a labeled product, follow the manufacturer's instructions only after confirming the actual ingredient with a pharmacist or doctor.

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

Read the full Gras monograph & all interactions
Medication

About Lanthanum

What Is Lanthanum Used For?

Brand name: Fosrenol

Lanthanum is used to lower phosphate in the blood of people with end-stage renal disease (ESRD). Both Fosrenol and generic lanthanum carbonate chewable tablets carry this use.

Managing high phosphorus in ESRD usually involves three things: eating less phosphate, removing phosphate with dialysis, and using a phosphate binder to reduce how much phosphate the gut absorbs. Lanthanum is the binder part of that plan.

See full Lanthanum drug information
Keep checking

Other Drugs & Gras

Browse every other medication we’ve checked against Gras — 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

Gras References

The 3 sources that drive our Gras monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Gras is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Dietary and Herbal Supplements — NIH NCCIH Source
  2. Herbs and Supplements — MedlinePlus Source
  3. Generally Recognized as Safe (GRAS) — U.S. Food and Drug Administration Source

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 Gras and Lanthanum Carbonate Together: Common Questions

Is it safe to take Gras with Lanthanum Carbonate?
We do not list a known interaction between Gras and Lanthanum Carbonate. 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 Gras and Lanthanum Carbonate at the same time of day?
At least one FDA label for a product containing Lanthanum Carbonate says to take it with food. If you take Gras on an empty stomach out of habit, keep them separate and take Lanthanum Carbonate with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Lanthanum Carbonate products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Lanthanum Carbonate interact with any supplements?
Yes. Lanthanum Carbonate has documented interactions with 17 supplements in our database — Gras is not one of them. The Lanthanum Carbonate 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 Lanthanum Carbonate and Gras?

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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.