Plan B dosage guide: how much to take and when
Choosing the right dose of Plan B (Levonorgestrel) is the most important practical decision after starting therapy. Plan B is supplied as tablet in 1.5mg, and the right dose for a given person depends on the indication, age, comorbidities and tolerance to the active ingredient Levonorgestrel.
Starting dose and titration
According to the prescribing information, most adults begin Plan B at the lowest available strength of 1.5mg and titrate up only if symptom control is insufficient and tolerability is good. Higher doses are reserved for selected cases. Older adults, people with renal or hepatic impairment, and those taking interacting medications should usually start at the lowest dose.
When to adjust
Dose adjustment is guided by symptom response and side effect burden, not by arbitrary schedules. Plan B's primary mechanism is delaying or preventing ovulation when taken before the LH surge. If side effects are limiting at a given dose, going down a step is usually preferred over stopping abruptly. If the response is incomplete after several weeks, a higher dose can be tried under medical supervision.
Frequently asked questions
What is the standard starting dose of Plan B? ▾
Most adults start Plan B at the lowest strength of 1.5mg, with adjustment based on symptom response and tolerance. Older adults and those with reduced kidney or liver function generally start lower. The prescriber decides the exact starting dose for each person.
Can I take a higher dose of Plan B if it isn't working? ▾
Higher doses of Plan B should only be used after consulting the prescriber. Doubling on your own is unsafe, especially with active ingredients in the Hormones and Birth Control class. The prescriber can confirm whether titration is appropriate or whether the medication needs to be changed.
More on Plan B
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.