Palbociclib is this inhibitor of CDK4/6, and it’s used for that type of breast cancer with HR /HER2 in its name. It keeps cells from moving forward in their cycle by stopping these cyclin kinases, 4 and 6. You can get it in different sizes—75 mg, 100 mg, or a chunkier 125 mg.
They suggest you take 125 mg each day for three weeks, then take a week off. One full cycle takes about a month. The drug comes in bottles with 21 pills—a whole week’s worth if you’re on the 125 mg dose.
