Disclosed is an improved composition characterized in containing a combination of melatonin and 5-HTP in a nasal administration for the rapid treatment of insomnia, anxiety, and related disorders in mammals, including humans. The present invention relates also to a pharmaceutical composition comprising 5-HTP and melatonin which utilizes the known effects of two substances to provide sleep improvement, relaxation, and reduced anxiety via rapid delivery of the combination, via nasal administration, for short-term alleviation of sleep disorder and anxiety-related symptoms. The combined effects of 5-HTP and melatonin in the present invention provide a short-term increase in blood plasma levels of melatonin while simultaneously increasing the production of serotonin for purposes of achieving natural melatonin biosynthesis in combination with the increased melatonin content in blood plasma.