So a 25% overdose maintained over a long period of time is dangerous? Say it ain't so!
If people ate 25% more than the recommended amount of lard every day for a long period of time, that'd be dangerous too.
Dosages do matter, people. The right amount is medicine. The wrong amount is poison. Always keep that in mind, don't take a higher dose unless you know what you're doing. And certainly don't stay on that higher dose for any significant amount of time unless you really know what you're doing. That goes for drugs, food, exercise, whatever.
But at the same time, it should be pretty obvious when you're doing it wrong. If you have chronic headaches and are taking ibuprofin or acetaminophen five times a day, every single day, that's not a good sign. That's a "you-need-to-see-a-doctor" sign.