its safe but def not necessary. most people get results with low dosages like chemar said. less is more in this regard, as melatonin is secreted by your pineal gland in low amounts anyways, so a low dose of melatonin, is just enough. 3mg is kind of an overkill, but won't harm you, just expect that you won't need to take it for a few days, cuz it'll still be there in your system.