Plan B with kidney impairment: dosing and safety
Kidney function affects how the body clears Plan B (Levonorgestrel) and many of its metabolites. For people with chronic kidney disease, dialysis, or even mild renal impairment from age or comorbidities, the standard 1.5mg dose may need adjustment. This page summarises the practical principles for Plan B in renal impairment.
Why renal function matters for Plan B
A meaningful fraction of Levonorgestrel or its active metabolites is cleared by the kidneys for many medications. Reduced eGFR slows clearance, raises plasma concentrations and prolongs effect. Plan B's primary mechanism is delaying or preventing ovulation when taken before the LH surge. The prescribing information for Levonorgestrel usually specifies dose adjustments by eGFR threshold (e.g. 30–60 vs <30 mL/min/1.73m²).
Practical guidance
According to the prescribing information, baseline kidney function should be checked before starting Plan B and periodically during treatment. People on dialysis need specialist input on dose timing relative to dialysis. Acute kidney injury — from dehydration, infection or other medications — can shift Plan B effects unpredictably and may warrant a temporary hold at 1.5mg.
Frequently asked questions
Is Plan B safe with kidney problems? ▾
Mild to moderate kidney impairment usually allows Plan B at adjusted lower 1.5mg doses with monitoring. Severe impairment (eGFR <30) often requires substantial reduction or alternative therapy. The prescriber decides based on lab results and the indication.
Do I need lab tests on Plan B if I have kidney disease? ▾
Yes — periodic eGFR and electrolyte monitoring is the standard practice for Plan B in chronic kidney disease. Frequency depends on the severity of impairment and on Levonorgestrel-specific risks. The prescriber sets the schedule.
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.