Cholesterol levels can be significantly affected by a medication called Lipitor, a type of drug known as a statin. In a normal physiological state, cholesterol is a fatty substance found in the blood, necessary for the body to build cells and produce hormones. However, high levels of cholesterol can lead to plaque buildup in the arteries, increasing the risk of heart disease [2].

Statins, such as Lipitor, work by blocking a substance your body needs to make cholesterol [3]. This results in lower levels of cholesterol in the blood, reducing the risk of heart disease and stroke [2]. According to the Cleveland Clinic, statins like Lipitor can lower LDL (bad) cholesterol by an average of 20 to 50 percent, and total cholesterol by about 15 to 30 percent [3].

Without Lipitor or other statins, cholesterol levels are typically managed through dietary and lifestyle changes. The Mayo Clinic recommends a heart-healthy diet, regular exercise, maintaining a healthy weight, and avoiding tobacco as methods to control cholesterol levels [1].

In summary, cholesterol levels differ significantly with and without Lipitor due to Lipitor's ability to block the production of cholesterol in the body. This leads to reduced LDL and total cholesterol levels, thereby decreasing the risk of heart disease.

Sources:
[1] <https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statins/art-20045772>
[2] <https://my.clevelandclinic.org/health/treatments/22282-statins>
[3] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>