You could ask your doctor. Each person is different. I wouldn't know.
I am 91.7lbs and am 13, what would happen if I took about 100-150mg of melatonin?
Considering that 10mg is the highest dose you should take to go to sleep, that amount will make you sleep and sick as can be. Melatonin is a natural sleep aide so I doubt it would kill you but you sure are going to be sick ! I suggest you don't try it for safety sake. Talk to your parents and Doctor if you are having sleep problems.
Should You Worry About a Melatonin Overdose? How Safe ...
One internet site points out that an "overdose" can be described as any dosage in excess of the recommended dosage.
Beyond that, there seems to be no consensus.
Here's a site you might check out: