If I dyed my upper lip hairs blonde prior to laser hair removal will the hair removal still be effective?

Great question!  Dying your hair blonde can reduce the effectiveness of laser hair removal if the dye lightened the deeper part of the hair.  Laser hair removal targets the pigment in the hair, but needs to target the deeper part of the hair in the hair shaft (bulb) to really "kill" versus damage the hair, leading to permanent removal.  Even if the hair is blond outside of the skin and properly shaved before treatment, it is still possible that some of the dye got into the skin and to the hair shaft and bulb, so it is not worth the risk in wasting a treatment.  I tell my patients that they should not do any bleaching, plucking, threading, waxing or any similar treatment for 6 weeks before treatment and throughout the entire treatment series.  

Hi! It's hard to say if the laser will be effective. The laser goes after the color of the hair, so if the hair got bleach all the way down in the follicle I wouldn't think it would work. However, I would think you could wait a few weeks and go without lightening the hair and it will work just fine as long as your natural hair is dark.
Hope that helps!