I basically stopped sleeping 50 yrs ago as a teenager. I have been treated for depression, bi-polar, low seratonin levels, breast cancer, IBS/constipation, weight gain (can t lose), low thyroid, and more! I have tried every OTC medication (100 mg Melatonin did nothing, even Cannabis oil), in addition to every old and new drug my drs could throw at me... I have all the sypmtoms of a melatonin deficiency, and was advised to get a pharmaceuitcal grade melatonin from a compounding pharmacy. In speaking with the pharmacist, he couldn t even tell me the difference between OTC and pharma grade. My doctor didn t know if there is a test for melatonin deficiency. The pharmacist told me to find a specialist who can treat hormonal imbalance which I think is also responsible for sleep disorders.