Soon in india 2 different CDK 4/6 inhibitors will be available thus widening treatment options for hormone positive metastatic breast cancer. CDK 4/6 inhibitors are new class of drugs recently approved for metastatic hormone positive breast cancer in combination with aromatase inhibitor. Availability in oral form makes them even more convenient for patients. 3 agents Palbociclib, Ribociclib and abamaciclib have been studied and found to show positive results, with only latter having effective CNS penetration. Palbociclib and Ribociclib are FDA approved based on results of PALOMA 2& 3 and MONALEESA 2 trial. These trials delayed symptoms of progression by close to 10 months. But do they prolong survival in metastatic breast cancer is a question which remains unanswered. Dose of Palbociclib is 125 mg after food in 3 week on 1 week off, while Ribociclib is available as 200mg tablet and three tablets with or without food is approved starting dose. As a class effect these drugs cause decrease in neutrophils but fever with neurtopenia is rare. In addition Ribociclib is associated with QTc prolongation and elevated liver enzyme. Hair loss or hair thinning is seen in a third of patients but never to the tune seen with conventional chemotherapy.