Atorvastatin, the generic name for Lipitor, is a medication used to lower cholesterol levels in the body. Like any medication, it can cause side effects. According to the NHS [2], common side effects of atorvastatin include nosebleeds, sore throat, headache, and an upset stomach. Some people may also experience muscle and joint pain, weakness, and fatigue. In rare cases, atorvastatin can cause serious side effects, such as liver problems, kidney failure, and muscle breakdown. These severe side effects are more likely to occur in people who take high doses of atorvastatin or who have pre-existing medical conditions.

Drugwatch [3] also lists some of the side effects that can occur while taking atorvastatin. These include nausea, diarrhea, constipation, and abdominal pain. Atorvastatin can also cause memory loss, confusion, and depression. In rare cases, it can cause allergic reactions, such as hives, swelling, and difficulty breathing.

It is important to note that not everyone who takes atorvastatin will experience side effects. Additionally, some people may experience side effects that are not listed here. If you are taking atorvastatin and are concerned about side effects, you should speak with your doctor.

Sources:
[2] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/
[3] https://www.drugwatch.com/lipitor/side-effects/