How long untill full regrowth ?

Hey I posted here before I had 2 ipl treatments on my legs. Just had the 3rd one done.
I’m just wondering how long after a treatment do you have to wait until all the hair that hasn’t been killed grows to its full size and width.
I waited 12 weeks after my 2nd ipl treatment and after 12 weeks I was actually happy with my results. I had 30-40 % reduction and most of the hair came back quite thinner.
If the hair doesn’t get any worse after 12 weeks I’m probably finished with my treatments after my 3rd witch I had yesterday.
(Just to specify I don’t want complete removal just having it thinned.)

And another question:
I had 4 ipl treatments on my moustache. It got thinned but I have a small patch on the right side that has like 20% more hair and the hair is thicker. Would 1-2 electrolysis treatments give me a reduction so both sides look more even? It’s a tiny patch but it’s quite obvious up close.

By 12 weeks most should come back. It’s not hair that wasn’t killed though, this is new growth in the next cycle. If hair wasn’t killed, it would grow back right away.

Don’t do IPL on your face! IPL is really bad on your face for causing new hair to grow. IPL in general isn’t as good since it’s not a real laser.

If you’re only looking for a reduction on your legs, then wait about 15-16 weeks before having another treatment. As edokid mentioned, if the hair wasn’t affected at all, it would be growing as usual right away and won’t shed at 3 weeks. Whatever was affected would shed by 3 weeks.