A Multicentre, Prospective, Open-label, Non-comparative Study

Inclusion Criteria: * All the following criteria must be met. * Healthy women aged between 18 and 35 years (inclusive) in need of contraception. * Subjects residing in Italy and having a good knowledge of the Italian language, such as to correctly understand the Informed Consent Form, the instructions for use, and to ensure potential adhesion to the study. * Subjects providing written Informed Consent Form. * Subjects willing to comply with the study protocol. Exclusion Criteria: * Subjects who meet even one of the following criteria will be excluded from the study. * Subjects presenting any contraindications to the use of Combined Oral Contraceptives (COC) according to the current Summary of Product Characteristics (SmPC) of Effimia®, i.e. subjects presenting (or have ever presented) myocardial infarction, transient ischemic attack (TIA), stroke, angina pectoris, deep vein thrombosis (DVT), pulmonary embolism (PE) (or presence of blood clot in other organs than legs and lungs), any blood clotting disorder (such as protein C deficiency, protein S deficiency, antithrombin-III deficiency), or subjects that need to undergo surgery or that have to lie down for a long period of time (including the risk of previous deep vein thrombosis (DVT), arterial thromboembolism (ATE), hypertension in course of treatment and diabetes). If any of the listed conditions should appear during the use of the tested COC, the product must be stopped immediately, and the subject withdrawn from the study. * Subjects presenting severe diabetes with blood vessel damages, heart valve disease with complications, severe hypertension, severe hypercholesterolemia, or hypertriglyceridemia, hyperhomocysteinaemia, migraine with aura, hepatitis C (and taking medications for this condition), endometrial hyperplasia, unexplained vaginal bleeding, that are breastfeeding or pregnant or that are suspecting a pregnancy. * Subjects presenting (or have ever presented) any liver disease not yet recovered (liver function not yet normalized), any benign or malignant tumour of the liver, any breast or genital organs cancer (even suspected), jaundice during pregnancy or while using hormonal contraceptives. * Subjects presenting galactose intolerance, total lactase deficiency or glucosegalactose malabsorption syndrome. * Subjects presenting hypersensitivity to the active substances or to any excipients of the tested COC (e.g., norgestimate, ethinylstradiol or lactose). * Subjects using the following not allowed treatments during the whole study period (according to the SmPC of the Investigational Medicinal Product - IMP): treatments for tuberculosis (e.g. rifampicin), for epilepsy (e.g. primidone, phenytoin, barbiturates, carbamazepine, oxcarbazepine), for HIV and hepatitis C virus infection (protease inhibitor drugs and non-nucleoside reverse transcriptase inhibitors such as ritonavir, nevirapine, efavirenz and also ombitasvir, paritaprevir, ritonavir and dasabuvir), for fungal infections (e.g. griseofulvin), for arthritis, for osteoarthritis (etoricoxib ), for pulmonary arterial hypertension (bosentan) and St. John's wort used as an antidepressant. Medicines containing cyclosporine, the antiepileptic lamotrigine, tranexamic acid, theophylline (used to treat respiratory problems) and tizanidine (used to treat muscle pain and / or cramps) should not be taken as well. * Subjects who have used hormonal contraceptives in the previous month. * Subjects presenting a Body Mass Index - BMI ≥ 30 kg/m2 (class I obesity). * Subjects smoking \> 15 cigarettes per day. * Subjects using COC off-label (e.g., for polycystic ovarian syndrome - PCOS, endometriosis, or recurrent menometrorrhagia). * Subjects currently taking part or who took part in clinical studies with experimental products in the previous month. * Subjects showing incapacity / inability to comply with the study protocol (unreliability in the intake of the product or in the completion of the diary) according to the Investigator's opinion.