Glad the Metformin is working! You’ll find that the finasteride will probably reduce additional body hair growth, but facial hair might be a little more resistant (these are all generalizations).
If you have coarse, dark hair, you’ll find that laser is often a useful procedure for removing these. How long it lasts is up in the air.
You don’t mention what area you’re getting treated with laser. If you are treating your face, most practitioners will set a schedule of treatment every 4 to 6 weeks depending on the rate of growth.
Some women have found it helpful to supplement Vaniqa with laser for dark facial hair. Although it has not been tested for effectiveness specifically on women with PCOS, there is clinical evidence and anecdotal data that it may be more helpful for women with new unwanted hair emerging (like postmenopausal women and transsexual women). It’s expensive, though, so you might see where you get with laser and your prescriptions before adding it.
Let me know what areas you’re treating with laser, and I’ll see what else I can find out!