If you miss a dose of phentermine you should take your phentermine pill as soon as possible. However, be cautious if it is too late in the day since the stimulant properties of phentermine may disrupt your sleep. In general, if you are planning to go to bed in the next eight hours, it’s probably better to skip the missed dose and take your next pill at the usual time.
You should NOT take the missed dose if you are within 12 hours of your next dose. NEVER take a double dose of phentermine. You can overdose on phentermine if you take too much in too little time.