Lipitor (atorvastatin) is a commonly prescribed medication for the treatment of high cholesterol. According to Drug Patent Watch [1], Lipitor's half-life is approximately 14 hours, meaning that it takes about 14 hours for half of the drug to be eliminated from the body. However, the duration of time that weakness persists after stopping Lipitor can vary based on individual factors.

A study published in the Journal of the American College of Cardiology [2] found that muscle-related symptoms, including weakness, occurred in less than 1% of patients taking Lipitor. The study also found that these symptoms resolved in the majority of patients within four weeks of discontinuing the medication.

Another study published in the Journal of Clinical Lipidology [3] found that muscle symptoms persisted for a median of 29 days after discontinuing statin therapy. However, this study included patients taking various types of statins, not just Lipitor.

It is important to note that weakness can have many causes, and it is important to consult with a healthcare provider if you are experiencing any symptoms after stopping Lipitor. They can help determine the cause of your symptoms and recommend appropriate treatment.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6019601/
[3] https://www.medpagetoday.com/cardiology/dyslipidemia/18423