Two medicines, side by side
Calcium carbonate vs magnesium hydroxide
Calcium carbonate and magnesium hydroxide are both labeled for acid reflux and ulcers. Pharmacies paid $0.0315 per tablet (Antacid ex-str 750 mg tablet chewable) and $0.0095 per mL (Milk of magnesia suspension) (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like.
Check it at the source: the calcium carbonate FDA label on DailyMed (effective December 5, 2024); the magnesium hydroxide FDA label on DailyMed (effective August 21, 2026).
Highlights of the calcium carbonate record
Calcium carbonate · label of December 5, 2024
Used for
From the label: indicationsrelieves • heartburn • acid indigestion • sour stomach • upset stomach associated with these symptoms
On the market
- Earliest approval on file
- n/a
- Generic labelers
- none listed
- Pharmacy cost
- $0.0315 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 1
Highlights of the magnesium hydroxide record
Magnesium hydroxide · label of August 21, 2026
Used for
From the label: indicationsrelieves occasional constipation (irregularity). This product usually produces bowel movement in 1/2 to 6 hours.
On the market
- Earliest approval on file
- n/a
- Generic labelers
- none listed
- Pharmacy cost
- $0.0095 per mL
Supply and safety
- Shortage
- No current entry
- Recalls
- 6
Source: FDA drug labels via openFDA (Calcium carbonate label of December 5, 2024, Magnesium hydroxide label of August 21, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do calcium carbonate and magnesium hydroxide differ on the record?
| Calcium carbonate | Magnesium hydroxide | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Constipation, Acid reflux and ulcers |
| Pharmacologic class | n/a | n/a |
| How it works (label) | n/a | n/a |
| Half-life (label) | n/a | n/a |
| Earliest approval on file (Drugs@FDA) | n/a | n/a |
| First generic approved | none | none |
| Generic labelers (NDC) | none listed | none listed |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0315 per tablet (Antacid ex-str 750 mg tablet chewable) | $0.0095 per mL (Milk of magnesia suspension) |
| 12-month price change | -0.8% | -2% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 1 | 6 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 66,848 | 13,458 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to calcium carbonate
- every medicine labeled for the same conditions