I have had it done twice! Sclerotherapy is what I had done where they injest some saline solution into the veins.
It did make some of the veins fade. If you have it done, follow the instructions of the support stockings. I did not and it would have made more of a difference if I had.
I just had twins and the veins are worse than ever. So I am going to tr laser this time around.
Good luck.
The laser methods work very well for thin spider veins and can last for a few years.