The length of time which threading of the eyebrows lasts depends mostly upon your hair type. Hair
can grow back to its original length in anywhere from 2 to 8 weeks but the average is around 4 to 5 weeks.
When the hair does regrow you will find it does not grow back quite so much and that the hair will grow back finer. The hairs regrowth will get finer and finer as you have threading done more often. The reason for this being it is pulled out at the root which over time makes the hair weaker.
Before your eyebrows are threaded, let me know how you want them shaped and how thin or thick you would like them to end up. If you do not have a natural arch and would like them shaped in that way more
hair would need to be removed to create the shape. If you do want a different shape to the brow, let them grow a little before having them threading, then I can see their natural shape and shape them more easily.
Try not to be tempted to start plucking or using a razor between appointments. This will thicken the hair and
make it more difficult to thread properly.