After conducting a thorough research, I found that Lipitor, a medication commonly used to treat high cholesterol, is not typically associated with weight gain as a side effect. According to the information provided by Drugs.com, the most common side effects of Lipitor include muscle pain, liver problems, and digestive issues such as diarrhea, gas, and bloating [1]. Similarly, the information from DrugPatentWatch.com does not mention weight gain as a potential side effect of Lipitor [2].

It is important to note that weight gain can be a result of various factors, including diet, lifestyle, and other medical conditions. If you are taking Lipitor and have noticed a change in your weight, it is recommended that you consult with your healthcare provider to determine the cause and appropriate course of action.

In conclusion, based on the available information, Lipitor does not cause weight gain as a side effect. However, if you have any concerns about your medication or its side effects, it is always best to consult with a healthcare professional.

Sources:
[1] <https://www.drugs.com/sfx/atorvastatin-side-effects.html>
[2] <https://www.drugpatentwatch.com/drugs/lipitor>