It usually takes several months for lash grow. If you feel that your lashes are rare or thin, you need a lot of patience while awaiting their return. Things you should know that lots of things can impact eyelash loss: your genetics, aging, hormones, lifestyle and even diet.
If your lifestyle behaviors are impacting growth rate and your age is retarding it as well, 12 weeks is the very outside for eyelash re-growth.
If you want to regrow lash back faster, you can take a try of lash conditioner. There has been some success with good eyelash conditioner such as Careprost. Some individuals report this increases eyelash growth. By using careprost, you will enjoy longer eyelashes in 4-8 weeks without any side effect.