Melatonin: Effective Sleep Aid or Public Health Threat?

I never had much luck using Melatonin. 500mg of Magnesium Oxide and hour before lights out has been working for me for years.
SGT James Murphy, CPT Jack Durish,
SPC Gary Welch, SGT Mark Anderson,
CPL Douglas Chrysler, LTC Trent Klug,
CSM Charles Hayden, SMSgt David A Asbury,
SSG William Jones, MSgt Robert "Rock" Aldi
SSG Michael Noll, MAJ Dale E. Wilson, Ph.D.
SGM Erik Marquez, CW3 Harvey K.
SFC William Farrell, CPL Ronald Keyes Jr
Sgt (Join to see), SSG (Join to see)
1SG Dan Capri, LTC (Join to see)