Aluminium hydroxide: what it is and how people use it

Aluminium hydroxide is a medicine often found in antacid products and as a phosphate binder for people with kidney disease. You’ve probably seen it listed on the label of a chewable tablet, liquid suspension, or gel. It works by neutralizing stomach acid and by binding phosphate in the gut so less gets absorbed.

For everyday heartburn, aluminium hydroxide products relieve symptoms fast. For people with chronic kidney disease, doctors prescribe it to lower high phosphate levels. Those are two very different uses, so how you use the drug and how long you can take it will vary a lot.

How to use it safely

Follow the package or your doctor’s directions. Liquid forms should be shaken and tablets often need chewing. If you’re using it for heartburn, take it after meals and before bed if needed. For phosphate control, dosing is usually spread across meals. Don’t take it on a strict schedule without checking with a clinician.

Mind the timing with other medicines. Aluminium hydroxide can bind several drugs and reduce their absorption. Common examples are tetracycline or fluoroquinolone antibiotics, levothyroxine, and some iron supplements. Give at least two hours between aluminium hydroxide and those medicines to avoid problems.

Side effects and warnings

The most common side effect is constipation. People sometimes combine aluminium hydroxide with magnesium hydroxide to balance this. Long-term use, especially in people with poor kidney function, can lead to aluminum build-up and bone or brain issues. That’s rare but serious. If you have kidney disease, talk to your nephrologist before using any antacid regularly.

Also watch for low phosphate signs if you take it a lot: weakness, bone pain, or trouble breathing. If you’re pregnant or breastfeeding, check with your provider—many clinicians prefer alternatives or limited use during pregnancy.

If you notice new muscle weakness, severe stomach problems, or changes in mood or memory, stop the drug and contact your doctor. For mild, occasional heartburn, short-term use is usually safe for most adults.

Alternatives include magnesium-based antacids (faster acting but may cause diarrhea), calcium carbonate (adds calcium), or for phosphate control newer prescription binders like sevelamer. Your choice depends on symptoms, kidney function, and other medicines you take.

Quick tips: read labels, space it away from other meds, don’t use daily for months without medical advice, and tell your doctor about all other prescriptions and supplements. If you’re unsure why a product contains aluminium hydroxide or how long to use it, ask a pharmacist — they can explain dosing and interactions in plain terms.

Typical over-the-counter doses vary by brand, but many chewable tablets deliver 200–400 mg per dose and liquid suspensions often give similar amounts per teaspoon; always check the label. Store at room temperature, away from moisture. Keep out of reach of children—accidental ingestion can be harmful. If you're switching from one antacid to another, compare active ingredients and ask a pharmacist which fits your health needs. Don't exceed package directions without advice today.