How long does it take swelling in leg to go down after warfarin started for a dvt?

Varies: It can go down in a matter of days to weeks or months or never. There is a condition call "post phlebiits syndrome" and the leg can be swollen for prolonged periods of time. I have patients with swelling for years after one or more clots in the veins of the legs.

Swelling: As the dvt starts to resolve or collateral veins take over the function,the swelling will improve Anticoagulants do not dissolve the clot

Important to know: Anticoagulation is to prevent further clot development or propagation. There is no enhanced dissolution of a DVT with anticoagulation. The timeframe and level of recovery is highly variable. Garments to help swelling has been important. In selective patients the early clearance of more proximal lower extremity DVT with the aide of pharmacomechanical endovascular therapies can help.