Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood and reduce the risk of heart disease [1]. While it is generally considered safe and effective, like all medications, it can cause side effects in some people. The timing of these side effects can vary depending on the individual and the specific side effect in question.

According to Medical News Today [2], some of the most common side effects of Lipitor include:

- Headache
- Muscle pain or weakness
- Joint pain
- Diarrhea
- Nausea
- Constipation
- Stomach pain
- Skin rash

These side effects can appear within the first few days or weeks of starting the medication. However, it is important to note that some side effects may not appear until months or even years after starting the medication.

In rare cases, Lipitor can cause more serious side effects, such as liver damage, kidney problems, and muscle breakdown [3]. These side effects are more likely to occur in people who take high doses of the medication or who have pre-existing medical conditions.

If you experience any side effects while taking Lipitor, it is important to talk to your doctor right away. Your doctor may be able to adjust your dosage or switch you to a different medication to help minimize side effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.medicalnewstoday.com/articles/drugs-lipitor-side-effects
[3] https://www.singlecare.com/blog/lipitor-side-effects/