Lipitor is a brand name for the drug atorvastatin, which is a type of medication used to lower cholesterol levels in the blood. According to the sources provided, some common adverse effects of Lipitor include muscle pain, joint pain, diarrhea, constipation, and nausea. These side effects may occur in up to 1 in 10 people taking the medication [2]. In rare cases, Lipitor may cause more serious side effects such as liver problems, muscle damage, and diabetes [1]. It is important to seek medical attention immediately if any of these more severe side effects occur.

Muscle pain is one of the most commonly reported side effects of Lipitor. This may be accompanied by weakness, tenderness, or a general feeling of discomfort in the muscles [2]. Joint pain is also a common side effect, which may be accompanied by swelling or stiffness in the joints [3]. Diarrhea and constipation may occur in some people taking Lipitor, as well as nausea and vomiting [2].

While most people can take Lipitor without experiencing any serious side effects, there is a small risk of more severe adverse effects. In rare cases, Lipitor may cause liver problems such as hepatitis or jaundice [2]. Muscle damage, known as rhabdomyolysis, is another rare but serious side effect that may occur in some people taking Lipitor [1]. This can cause muscle pain, weakness, and dark urine. In some cases, rhabdomyolysis can lead to kidney damage or failure.

Finally, Lipitor may also increase the risk of developing diabetes in some people [1]. This risk is higher in individuals who have pre-existing risk factors for diabetes such as obesity or a family history of the disease.

In conclusion, while Lipitor is generally well-tolerated by most people, it can cause some common side effects such as muscle pain, joint pain, diarrhea, constipation, and nausea. In rare cases, more serious adverse effects such as liver problems, muscle damage, and diabetes may occur. It is important to seek medical attention if any of these more severe side effects occur while taking Lipitor [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003
[3] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/