Lipitor is a brand name for atorvastatin, a medication used to lower cholesterol levels. According to the Drug Patent Watch [1], Lipitor is a statin that works by inhibiting the enzyme HMG-CoA reductase, which plays a key role in cholesterol synthesis.

The effectiveness of plant-based substitutes on reducing Lipitor's effectiveness is not directly addressed in the provided sources. However, a study reported by NPR [2] found that plant sterols, which are found in many plant-based substitutes, can lower cholesterol levels by blocking the absorption of cholesterol in the gut. This suggests that plant-based substitutes could potentially have a positive effect on cholesterol levels, but it is unclear whether they would interact with Lipitor or reduce its effectiveness.

The Healthline [3] article compares statins and plant sterols and notes that while both can lower cholesterol levels, statins are generally more effective and have been extensively studied and tested. It is important to note that plant sterols are not a substitute for medication and should not be used as the sole treatment for high cholesterol.

In conclusion, while the provided sources do not directly address whether plant-based substitutes can reduce Lipitor's effectiveness, plant sterols found in many plant-based substitutes have been shown to lower cholesterol levels. However, statins like Lipitor are generally more effective and should not be replaced by plant-based substitutes. It is important to consult with a healthcare provider before making any changes to cholesterol-lowering medication or diet.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.npr.org/sections/health-shots/2022/11/06/1134094540/statins-vs-supplements-new-study-finds-one-is-vastly-superior-to-cut-cholesterol
[3] https://www.healthline.com/health/high-cholesterol/statins-vs-plant-sterols