Not yet investigated
What we have so far
They block the pump that puts hydrogen ions into the stomach. Among the most prescribed drugs on earth, and among the most continued indefinitely without anyone revisiting why.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.