I don't recommend taking more than 20mg of DMAA at a time, and the effects last for about 4 hours. If you don't get the effects you want at this dose, then I wouldn't recommend taking it.
I tend to run on the low side of NE. When I trialed DMAA, I noticed for the first couple days, it would cause a tad bit of euphoria (presumably from releasing serotonin), then these effects would go away. In the following days, I would consistently get NE release without the euphoria. I would take one in the morning, and then one around 2 in the afternoon. I think this is why I did not build a tolerance to the NE releasing properties, because it's half-life is so short.
The main problem with DMAA is that most people are taking too much of it, and for the wrong reason. It's not a safe product in the way that it is usually used. I used it for increasing concentration and as a decongestant.
It will cause your heart rate to increase. That's what adrenaline does. I really don't recommend it for exercise, weight loss, or for anyone prone to anxiety, heart problems or has any kind of disease.
Edited by zrbarnes, 13 July 2012 - 01:47 AM.