Is it okay to take 7.5 mg melatonin nightly?was on 5 mg for years but wokee up alot in night.on 7.5mg, i fall back asleep more easily after i wake up. groggy in am but wears off quickly & feel more rested the next day.might i build up an intolerance?

Yes: Quality and accuracy of dose listed on the bottle will vary. The Rx version is higher yet! 7.5mg is ok if it works, but I sense a bad trend: if 5mg worked but stopped and you now need 7.5mg to sleep, this dose will stop working after a while. Explore non med sleep hygiene,such as no caffeinated drinks after 5pm, same bed and awake times, no naps, dark cool room, bedroom for sex/sleep only,