Anecdotally, higher doses result in less pain for me, too. But, I'd caution anyone who was chronic migraines, or any sort of chronic pain, to limit themselves to a few standard doses a week. My doctors kept telling me that I likely had Medication overuse headaches, and I kept going "no way, I don't take that much, and I've had regular headaches before taking my current regiment." Finally, after years of prompting, I toughed out three weeks with no medication and my severe migraines were reduced in duration afterwards. Please be very careful of this slippery slope.
I'm usually not the type of guy to dunk on a journal for having low impact factor but uh...
Impact-factor 0 journals are a really really bad sign. An extremely bad sign. I wouldn't recommend taking it seriously at all. It's like a limbo for damned papers that were rejected from every other publication. You see things in there. Things you can't forget. Entire plagiarized papers that were Google translated to Chinese and then back to English. That internet meme where some guy literally put "T" on top of his bar plot instead of real error bars. Forgetting to correct for multiple hypotheses. Unforgivable sins.
My best recommendation is to look for a higher-quality source.
Thank you for your feedback! This is a mistake on my part. I will take the article down until I've looked into this and have updates my resources.
Edit: I have updated the article. It should be better now :)
I use ibuprofen almost exclusively because a source I trusted told me years ago that it was better for me longterm than acetaminophen (alas I have no idea what the source was) but I think the same principle applies. I always take one pill to start because I worry about developing tolerance / rebound headaches / kidney damage / stomach upset, and then if that doesn't seem to make a difference within 60-90 minutes, I take a second one. I find that usually I need two (i.e. the recommended dose), perhaps since I only take painkillers at all when the pain has risen beyond a certain level, but sometimes one is sufficient.
I realize this isn't actually evidence that a half-dose is at all distinguishable from placebo, but the point is, if you worry about overuse like I do (e.g. because you have a chronic condition), I see no reason to not just take one pill to start. If it alleviates your pain, then great, if not, you can take another.
I get a lot of headaches, and for a while had the cached belief that ibuprofen was the way to go and acetaminophen (paracetemol) doesn't work on me at all. But after a c-section I was given the big doses of both, and told to alternate, and I noticed that I could definitely tell the difference between skipping/delaying an acetaminophen and taking it on time. So now I use that for headaches, especially sinus-y headaches where I don't want to suppress my immune response that's trying to get my cold to go away.
Interesting. I didn't know that anyone ever took just one paraceatamol. In the UK the packets all say that the dosage is two tablets, unless you are a small child. So people just kind of follow the instructions (at least I do). I have migraines infrequently (once a month, slightly less) but when I do realise I am having a migraine their is no way I am taking any paraceatamol less than what the packet stipulates. Firstly because I am in pain, and secondly because migraines seem to fog up by basic cognition in weird ways - I get weirdly stubborn about following instructions. Imagine me there, my vision swimming, can't read because my sight is blury and the room is spinning. But the box says to "Always read the instructions in full before use" so I have to read this tiny text on this little paper before I can have my paracetamols. So when the instructions tell me 2, that is what it shall be. (I now throw the instructions away while sane).
In the hospital, we usually give 1g IV for any real pain. I don't think the notion that giving more of a painkiller would produce a stronger effect is particularly controversial!
(Anecdotally, the IV route is somewhat more effective, even though the nominal bioavailability is the same as the oral route. It might be down to faster onset and the placebo aspect of assuming anything given by a drip is "stronger")
In the hospital, we usually give 1g IV for any real pain. I don't think the notion that giving more of a painkiller would produce a stronger effect is particularly controversial!
(Anecdotally, the IV route is somewhat more effective, even though the nominal bioavailability is the same as the oral route. It might be down to faster onset and the placebo aspect of assuming anything given by a drip is "stronger")