Plan B with liver impairment: dosing and safety
The liver is the main site of metabolism for many medications including Plan B (Levonorgestrel). Liver impairment slows clearance and can raise plasma levels of Levonorgestrel above the intended range, amplifying side effects. People with chronic liver disease, recent hepatitis or significantly raised liver enzymes need a tailored approach to Plan B at 1.5mg.
Why liver function matters
Levonorgestrel undergoes hepatic metabolism through CYP enzymes for many medications. Reduced hepatic function slows this metabolism, prolongs the half-life and raises plasma concentrations. Plan B's primary mechanism is delaying or preventing ovulation when taken before the LH surge. The prescribing information typically classifies severity by Child-Pugh score (A mild, B moderate, C severe) and gives dose adjustments accordingly.
Practical guidance
According to the prescribing information for Levonorgestrel, baseline liver function tests are recommended before starting Plan B in any patient with risk factors and periodically during treatment in chronic liver disease. Severe impairment (Child-Pugh C) often contraindicates Plan B or requires substantial dose reduction; mild impairment usually permits standard 1.5mg with closer monitoring.
Frequently asked questions
Is Plan B safe with liver problems? ▾
Mild liver impairment typically allows Plan B at standard or slightly reduced 1.5mg with monitoring. Moderate-to-severe impairment often requires substantial dose reduction. Severe (Child-Pugh C) impairment may contraindicate Plan B entirely.
Will Plan B damage my liver? ▾
Most Hormones and Birth Control medications at standard 1.5mg doses do not harm a healthy liver. A small subset can produce drug-induced liver injury in susceptible patients, usually detected by routine ALT/AST monitoring. The prescribing information for Levonorgestrel lists the documented risk.
More on Plan B
- With alcoholPlan B and alcohol — is it safe to drink?
- With foodShould Plan B be taken with food?
- Side effectsPlan B side effects: common, rare and warning signs
- Dosage guidePlan B dosage guide: how much to take and when
- OnsetHow fast does Plan B start working?
- DurationHow long does Plan B last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.