I just got a sample of 50 mg dose, but I am worried about the sid...

I just got a sample of 50 mg dose, but I am worried about the side effects. I am 18 and somewhat overweight but in overall decent health, but my doctor who gave the sample to me says my blood sugar & cholesterol could decrease, and there have been very rare cases of involuntary/uncontrollable facial movements. I know each patient has different side effects, but are the more severe ones more common? I don't know if I should wait to take them, or take the risk.