According to the sources provided, it is not recommended to use expired Lipitor. Drug expiration dates do matter and expired medications may not be as effective or safe as they were when they were fresh [2]. The effectiveness of a drug can decrease over time, and expired medications can even cause harm due to the breakdown of the active ingredients [2][3]. In the case of Lipitor, it is a prescription drug used to lower cholesterol and reduce the risk of heart attack and stroke [1]. It is important to follow the instructions of your healthcare provider and pharmacist and dispose of any expired medications properly [2]. Therefore, it is not advisable to use expired Lipitor and it should be safely disposed of.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.health.harvard.edu/staying-healthy/drug-expiration-dates-do-they-mean-anything
[3] https://link.springer.com/article/10.1007/s40090-017-0120-5