 [ Symptoms ] what foods trigger migraines and headaches [ Disease ] ldn [low dose naltrexone] usually takes one to two weeks to start working and can take up to a month or two to achieve the full effect it tries to restore the body is normal endorphin rhythm with the beneficial pain and immune system effects and this takes a while when i prescribe this med i tell my patients to try it for at least a month to allow enough time to determine if it is helpful