Yes. After taking the emergency contraceptive Plan B (levonorgestrel), it is considered safe to drink alcohol, and alcohol is not known to alter the efficacy of Plan B.
There is no mention of a potentially harmful interaction between alcohol and levonorgestrel on the prescribing information packets for Plan B One-Step or the two-dose Plan B. The National Institute on Alcohol Abuse and Alcoholism also does not include Plan B or any other contraceptive method on its list of commonly used medicines that have known interactions with alcohol.
While consuming alcohol after Plan B is not considered dangerous, some of the potential side effects of Plan B may be worsened by alcohol. For example, Plan B can sometimes cause side effects such as:
- Tiredness
- Nausea
- Headache
- Vomiting
- Dizziness
Drinking alcohol can also cause these symptoms, potentially leading to more or worsened side effects if combined with Plan B. Other side effects of Plan B include lower abdominal pain and menstrual changes.
There are certain medications and herbal supplements that you should avoid after taking Plan B, as they may lower the efficacy of the drug. These include:
- Barbiturates (including primidone)
- Bosentan
- Carbamazepine
- Felbamate
- Griseofulvin
- Oxcarbazepine
- Phenytoin
- Rifampin
- St. John’s wort
- Topiramate