I started using this over a year ago and it has helped my brow hair growth. I use it day and night but sometimes only use it on a night. I found it made my hairs strong and did help with brow growth. I find that if I stop using it my hairs are not as strong and become weak again. That’s a downside to this product as you have to keep using it and it’s not cheap,I get mine from amazon as it’s cheaper. They have also changed the spool, it used to be full size like a brow spool or eyelash one, they have changed it too half the size at first I thought mine had broke but when I got my next one it was the same, I prefer the full sized spool than the newer sized one but it still does the job.