No, cumin (Cuminum cyminum) is not related to curcumin. It's also not black cumin, which is an unrelated plant marketed as a health product. The active compound seems to be cuminaldehyde, which is also found in perilla. I haven't found a convenient source of perilla, so I haven't tested it yet, but I think it would work.
I take a level tsp of ground cumin. Much less than that isn't fully effective. More than that isn't more effective, though it last slightly longer (I gave an example earlier in the thread). I hold it under my tongue for a while, in hopes that improved transport into the brain makes a difference, but it probably doesn't. I've mixed it into pancakes as well, and it doesn't seem affected by the heat. I haven't noticed any side effects. I don't actually like the taste myself, but it's not so awful that I'd bother putting it in capsules or masking the taste. Maybe swallow a half tsp quickly and rinse with something tasty?
For me, the level tsp is effective, and lasts three days. Given how everyone seems to react differently to things, you'll need to experiment for what works for you, assuming that it has any effect at all. Since cumin is cheap, easy to find, and safe, I was expecting everyone in the forum to try it, and I was really expecting some people to find that it works for them. It's made a huge improvement in my quality of life.
If you do try it, please post results, even if it's 'no effect'. Even negative results are useful information.