Aluminium hydroxide is a common ingredient in over-the-counter antacids, with some products containing up to 500 mg of aluminium per dose. Chronic use can significantly increase systemic aluminium levels.
I didn’t fact check it, though.
Edit: I think I found a better source, and a better quote
Antacids have 300–600 mg aluminum hydroxide (approximately 104–208 mg of aluminum) per tablet, capsule, or 5 milliliter (mL) liquid dose. Little of this form of aluminum is taken up into the bloodstream.
Oral exposure to aluminum is usually not harmful. Some studies show that people exposed to high levels of aluminum may develop Alzheimer’s disease, but other studies have not found this to be true. We do not know for certain that aluminum causes Alzheimer’s disease.
Some people who have kidney disease store a lot of aluminum in their bodies. The kidney disease causes less aluminum to be removed from the body in the urine. Sometimes, these people developed bone or brain diseases that doctors think were caused by the excess aluminum.
Although aluminum-containing over the counter oral products are considered safe in healthy individuals at recommended doses, some adverse effects have been observed following long-term use in some individuals.
Maybe it’s not that bad
I didn’t fact check it, though.
Edit: I think I found a better source, and a better quote
Source: https://wwwn.cdc.gov/TSP/PHS/PHS.aspx?phsid=1076&toxid=34