One study showed more than a 600% increased risk of blood clots for women taking COCPs with drospirenone compared with non-users, compared with 360% higher for women taking birth control pills containing levonorgestrel.  The . Food and Drug Administration (FDA) initiated studies evaluating the health of more than 800,000 women taking COCPs and found that the risk of VTE was 93% higher for women who had been taking drospirenone COCPs for 3 months or less and 290% higher for women taking drospirenone COCPs for 7–12 months, compared with women taking other types of oral contraceptives. 
Short CV Alessandro Gandini Born in Italy, 1940. Keele University, UK, 1965. Research and Teaching in Polymer Chemistry, Photochemistry and Physical Chemistry, in Switzerland, Canada, USA, Cuba, France, Brazil and Portugal plus invited professorships in the UK, Italy, Tunisia, Uruguay, Costa Rica, China, Argentina, Mexico and Spain. Major research interests: Polymers from Renewable Resources and Physical Chemistry of Surfaces and Interfaces. More than 440 publications and 470 communications at scientific symposia, including some 150 invited or plenary lectures. More than 20 Patents. Some 80 Doctorate Theses directed or co-directed. Fellow of the Royal Society of Chemistry and of the International Academy of Wood Science. Member of the International Expert Council on the Chemistry of Vegetable Resources of UNESCO. Honorary Doctor of St. Petertsbourg Forestry Academy and of Havana University.