One reason for self-experimentation is very simple: To learn about the effects of a drug you are taking. Is it helping? The medical literature is unlikely to be unbiassed. Someone heavily involved in producing that literature wrote anonymously in the BMJ:
I also do a lot of ghost writing. Sometimes I report good quality studies to which I am proud to contribute, albeit anonymously. Yet, too often, I write so called reviews, amounting to mere panegyrics of the discussed drugs, or I report poorly designed and implemented “epidemiologic” studies, bearing gross biases. Many of the (paid) signing authors of these papers do not read the manuscript, let alone provide feedback. I am surprised at how easily such papers are accepted by some journals and how rarely their flaws are challenged.
Given the financial interests at stake, I do not see what recommendations or regulations will put an end to such long debated [meaning long-criticized] practices.
My first self-experimentation to have unexpected results involved an acne drug. I discovered it was ineffective — might have even been making things worse. Yet it was a standard treatment for acne. My dermatologist was surprised I had bothered to collect the data. “Why did you do that?” he asked.
To do useful self-experimentation here isn’t complicated. The main thing you would do would be to measure the problem before and while you take the drug. Before you take the drug, you’d want to measure the problem long enough so that you had some idea of what would happen if you didn’t take the drug.
If you’ve done this, I’d like to hear about it.
I was discussing self-experimentation with a colleague recently (https://en.wikipedia.org/wiki/Sébastien_Paquet) and he told me that he wrote his thesis by self-experimentation. (His Ph.D. was in Computer Science… though it was not very typical.)
His goal was to measure the impact that blogging has on a career and his research. On purpose, he became highly connected. Of course, this is contrary to the scientific method: you can’t be your own object of study. Yet, it worked well enough for him.
My own research (databases) is not a very good area for self-experimentation. However, for things like social networks, where researchers are currently struggling due to the lack of a convenient methodology, it could be that self-experimentation could help a lot.