Original prescription recommendations were 20-60mcg/d. That's all I take anymore. That's also the dosing range where it is most selective. Selectivity is all about thresholds, no matter what the compound is. Most people blow by the selective threshold. In fact, most of the time, the way people take it, they seem to purposefully do so.
I'm curious about Mirabegron. It's a new Selective Beta3 Agonist. Years ago, that's all everyone was waiting for. Now that we have it, no one is taking it in bodybuilding.
Anymore I wonder why I'd even bother with Selective Beta Agonists. Clenbuterol is selective for certain Adrenalin receptors. It gets you wired, but without a sense of well being. There is no Dopamine to compliment.
When you take Amphetamines, Ephedrine, or any Releasing Agent, you get both Norepinephrine and Dopamine, so you get a sense of well-being, as well.
Personally, I'm tired of being wired without truly feeling good.
I'd rather take a comprehensive stack and just tune down the Clenbuterol.