Uncommon side effects (affects 1 to 10 users in 1000) are: • Increased risk of blood clots in the legs (deep vein thrombosis) • Increased risk of blood clots in the lungs (pulmonary embolism) • Increased risk of blood clots in the eyes (retinal vein thrombosis) • Skin around the vein is red and painful (superficial vein thrombophlebitis)