Will it hurt?
Only if you leave ANY hair unshaved prior to using, otherwise, no, it doesn't hurt at all.
How long did pale skin and dark hair users take until they saw a difference?
I have very pale skin and almost black dark hair, so the 'perfect candidate'. Everyone will have a different answer as everyone's hair is different, but my hair is thick and coarse, and this has been my experience.
About 8 weeks, 4 sessions in total, maybe even 6 sessions. Legs were the first to take effect, I now rarely use the IPL on my legs and rarely shave. The occasional hair will grow about an inch long in that time and it's pretty scary
I forget my leg hair exists. VERY big deal for someone who had to shave daily!
Underarm hair took 6 sessions, but again, I now only have to do maintenance IPL every now and again. Upper lip hair has been a little more stubborn, it has a tendency to regrow and not stay put like the leg and underarm.
Bikini - sigh..... this is taking a long time to IPL away, but it is the coarsest of the coarse and I still think I'll reach a day where it is no more. TBH I haven't been a consistent every-2-week user, hence why I think it's been so stubborn.
Can I use it once a week, impatient? Has anyone done that?
Pre-holiday impatience has led to me doing this, and it does work....not sure it's recommended long term though so I didn't do it too often.
Should it have a two pin (European) plug or 3 pin UK plug if I bought it in the UK?
Having bought a two pin hair dryer in the past, get it replaced, it's the biggest pain to use as it constantly falls out of the convertor plug.