I usually use it during the day, as soon as I see that I am about to get anxious, I take a tablet. I don't use it on a daily basis, nor so much to sleep, but rather to relax. I have tried various brands and none of them have caused me any unwanted side effects, including this one. For sleep, I prefer serotonin if needed.

It causes me anxiety and gastrointestinal problems with stomach pain.
It is not for insomnia. It has side effects.