Growing new dopamine receptors - do watch this video (full video available on her channel)

You can't technically "fast" from dopamine. It is released in anticipation of a reward and the definition of that can go as far as quenching your thirst or your hunger.

Besides, there's really no point from abstaining from dopaminergic activities if you're only going to do it as a one off thing. The way to make change in your life is if you live by dopamine detoxing, and the exception being indulging (in non harmful habits) for a break.

 

OP should really say the name of the video and uploader, so people dont have to click on sketchy links (im not clicking on it)