first time in years, curious how to dose

been about a decade since i last took this and i have a 10mg zolpidem (p sure thats how its spelled) is 2.5mg enough to feel for an adult male in his late 20’s without making me black out (weigh about 145) i remember blacking/browning out off a full one in highschool. just not trying to be obviously fucked up in front of family/not pass out suspiciously when im known not to take stuff like this often.