ast week I took 300 mg of vitamin b6 and 15 mg of melatonin right before I went to bed and I couldn't sleep a wink. That night I slept for roughly 3 hours. It's been a week now, so I'm ready to try vitamin b6 again. However, I'm not sure when is the best time to take it. I don't want to have insomnia again. It was painful.