Is it better to split oral minoxidil doses or take it all at once?

[Adri23]

I'd like to start with 5mg again but I had some nasty heart side effect with that dose. I'm now on 4mg without sides. I'd like to take 2.5 mg morning and 2.5 mg night to see if I can tolerate it that way, but I don't know if it is as effective as taking 5 mg at once.