Can a 18 year old use IUI treatments?

It all depends on the reason your boyfriend's infertility, some times IUI doesn't work and you would need IVF and or ICSI which his very expensive.I would try some herbal and vitamins treatment first.Ginseng, Maca Root, L-Cartenine, and B-complex with Zinc, at least for 3 months and let him take a new test.Good luck!