There is no direct evidence to suggest that Lipitor, a medication used to lower cholesterol levels, affects flexibility during yoga. Lipitor's active ingredient, atorvastatin, works by inhibiting the enzyme responsible for producing cholesterol in the liver [1]. While some studies have suggested that statins like Lipitor may cause muscle weakness or myopathy, which could theoretically affect flexibility [2], the vast majority of patients taking Lipitor do not experience these side effects [3]. Furthermore, a study published in the Journal of Clinical Lipidology found that Lipitor did not significantly affect muscle strength or flexibility in patients with high cholesterol levels [2]. Therefore, it is unlikely that Lipitor would have a significant impact on a person's ability to perform yoga poses. However, as with any medication, it is important to speak with a healthcare provider about potential side effects and interactions with other medications before starting Lipitor or any other prescription drug [3].

Sources:
[1] Drug Patent Watch. (n.d.). Lipitor. Retrieved from https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] Kostapanos, M. S., Milionis, H. J., & Elisaf, M. S. (2012). Do statins beneficially or adversely affect muscle function? Evaluation of the clinical evidence. Journal of Clinical Lipidology, 6(2), 82-89. doi: 10.1016/j.jacl.2011.11.003
[3] EurekAlert!. (2019, August 27). Statins not associated with a reduction in cardiovascular disease events in healthy older adults. Retrieved from https://www.eurekalert.org/news-releases/922992