Hi, San! The thing with cinnamon is that it was discovered quite by accident. IR folks in a study were found to have better fasting glucose levels if they happened to eat apple pie. (Happening to eat apple pie was purely a coincidence, from what I read.) Researchers eventually discovered it was the cinnamon in the apple pie that was actually doing the trick. With more studies isolating cinnamon in the diet, it was clear that consuming cinnamon will help normaluze fasting glucose levels in those with insulin resistance.
So, yes, you can just add actual cinnamon to food and drinks.
Myself, though, I take a cinnamon supplement I buy at the grocery store. It's also available at most pharmacies I've checked (but just more convenient to pick-up with the rest of my groceries.) However, there is just that one manufacturer, in my area. (i.e. all my local shops sell the same brand.) There is more variety online.
The one I buy is the cinnamomum cassia variety. I would love to try the cinnamomum verum variety, but can't find it locally. Still, the one I'm taking works just fine.
I take 3,000mg/3g per day. Twice I've tried reducing it to 2g, but my weight loss halted during those days. So, for now at least, I have to stick with 3g.
The only real concern I've read about, in terms of long term use, is blood thinning. I even read that some women stop taking cinnamon during their periods. So, you can imagine how curious I was when the time came for that first period. Funny enough, it was the shortest and lightest period ever. I've now had three periods since starting cinnamon; all shorter and lighter than usual. So...
Once I get to a weight I want to stay at, I'll play with lower dosages, and see what happens. But, to my knowledge, lots of people do take the cinnamon from the spice rack and just add it to food and drinks, for the same result. I didn't want to grow tired of the taste of cinnamon (plus, I don't eat/drink too many things which are conducive to adding cinnamon), and I wanted an exact dosage. That's why I went with capsules. I generally take 3 500mg capsules with breakfast and three with dinner. I have done 2/2/2 breakfast/lunch/dinner...which is probably physiologically better, but I've just found it easier to do twice a day. I will either skip my dosage or reduce it if I do eat oatmeal with cinnamon or a chai tea that is heavy on the cinnamon, for example.
A bottle of 100 capsules lasts me about 16 days. It's usually about $15 per bottle, but I did recently score a few on sale at half price.
I hope that helps!