How come first time i took sedative, i took 5mg diazepam and it had very little sedative effect. how come? i felt same as before taking, little tired

Well;: Factors assessing effect: Your weight, the age of the medicine, if you took it with food or an empty stomach, if you used stimulants like caffeine or nicotine with it, amount of stimulants used, level of stress, and expectations of the effect. A few genes as well. All of these may have had an impact on what the medicine did to you and for you. Also, your activity level impacts this.