Fifty seven patients with secondary lymphedema of the upper limb after previous treatment for breast cancer were treated for 3 months with an extract of Ruscus + Hesperidin Methyl Chalcone (CYCLO 3 FORT) or placebo according to a double-blind protocol in the context of a controlled clinical trial. All patients also underwent manual lymphatic drainage twice a week for at least one month. With CYCLO 3 FORT, the reduction in volume of arm edema, the main assessment criteria, was 12.9% after 3 months of treatment as compared with a placebo (p=0.009). Decreased edema tended to be more marked in the forearm compared with the upper arm where excess fat deposition seemed to dominate over excess fluid accumulation. CYCLO 3 FORT was well tolerated with minimal adverse reaction.