The International Headache Society recommends the outcome of being pain-free two hours after taking a medicine as a standard measurement. The outcome of being pain-free or having only mild pain at two hours was reported by 59 in 100 people taking paracetamol 1000 mg, and in 49 out of 100 people taking placebo. This means that only 10 in 100 or 10% of people benefited because of paracetamol 1000 mg.
Meanwhile the recommended dosage is really really close to the dangerous dosage. Tens of thousands of people a year in the US alone suffer from liver damage or failure because of it.
Findings from one 2022 clinical research trial suggested that regular daily intake of 4 g acetaminophen increased systolic blood pressure in individuals with hypertension by about 5 mm Hg compared with a placebo. The study concluded that this increase in cardiovascular risk calls into question the safety of regular acetaminophen use in similar situations.
It is the leading cause of acute liver failure in the U.S., and the drug in some cases has led to fatalities. The active ingredient in Tylenol, acetaminophen, accounts for more than 100,000 calls to poison centers, roughly 60,000 emergency-room visits and hundreds of deaths each year in the U.S. In England, it is the leading cause of liver failure requiring transplants.
https://www.cochrane.org/news/featured-review-oral-paracetamol-treatment-acute-episodic-tension-type-headache-adults
Meanwhile the recommended dosage is really really close to the dangerous dosage. Tens of thousands of people a year in the US alone suffer from liver damage or failure because of it.
https://www.drugwatch.com/drugs/tylenol/
This is all pretty well known facts by now.