I started both electrolysis and laser at about the same time. About 30% of my facial har was grey/white. Laser is great for dark hair, but my electrolocist has noticed that laser seems not to have any effect even on the light brown hairs. My electrolocist had only been targeting the grey hairs, but after six facial laser treatments I gave her the green light to go after any hair she finds. The laser is helping quite a bit, but some hairs can be stubborn.
I also had laser done on my back. Although I really don't like any body hair, the hair on my back bothered me the most. After five laser treatments my back hair is virtually gone. The last time I went in they were amazed how clear it was and decided to do face only that day. I don't check my back for hairs very often, but it has been several months since I noticed any there.
I expect HRT helped some with the back hair. I also had quite a bit of chest hair and it is thinning out fast. I still may get a few laser treatments on my chest, stomach, and legs, but it is possible HRT may reduce the hair in those areas to a manageable level without laser.