Based on the available information, Lipitor (atorvastatin) has not been directly linked to side effects on protein absorption. Lipitor is a statin, a type of drug used to lower cholesterol levels in the blood by reducing the production of cholesterol in the body and increasing the removal of low-density lipoprotein (LDL), or "bad" cholesterol, from the blood by the liver [1].

The FDA-approved label for Lipitor does not mention any side effects related to protein absorption [2]. Additionally, a review of atorvastatin's effects on muscle and liver, published in the journal Circulation Research, does not mention any impact on protein absorption [3].

It's important to note that while Lipitor does not have a direct impact on protein absorption, it can interact with other medications that affect protein absorption or metabolism [1]. Therefore, it's crucial for individuals taking Lipitor to inform their healthcare provider of all medications and supplements they are taking.

In summary, based on the available information, Lipitor has not been shown to have side effects on protein absorption. However, it can interact with other medications that affect protein absorption or metabolism.

Sources:

[1] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
[2] <https://www.ncbi.nlm.nih.gov/books/NBK430779/>
[3] <https://www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.118.312782>