The effectiveness of the cholesterol-lowering drug Lipitor can be reduced by certain supplements. According to a study published by NPR [${2}], some supplements can be vastly inferior to statins like Lipitor when it comes to cutting cholesterol. However, the specific supplements that can interfere with Lipitor's effectiveness are not explicitly mentioned in the study.

It is known that Lipitor, a type of statin, works by blocking a substance your body needs to make cholesterol [${1}]. Therefore, taking supplements that contain cholesterol or increase cholesterol levels in the body could potentially interfere with Lipitor's effectiveness.

Additionally, it is important to note that some supplements can interact with medications like Lipitor and cause side effects. For instance, red yeast rice, a dietary supplement, contains a substance similar to prescription statins and may increase the risk of muscle and liver problems when taken with Lipitor [${3}].

In conclusion, while the specific supplements that reduce Lipitor's effectiveness are not explicitly mentioned in the study, it is advisable to consult with a healthcare provider before taking any supplements while on Lipitor or other statins.

Sources:

* <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
* <https://www.npr.org/sections/health-shots/2022/11/06/1134094540/statins-vs-supplements-new-study-finds-one-is-vastly-superior-to-cut-cholesterol>
* <https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013>