Yes it is safe to use krimson 35.
The use of oral contraceptives increase the risk of- thrombophlebitis,arterial thromboembolism
,pulmonary embolism,myocardial infarction
,cerebral thrombosis,hypertension,hepatic adenoma,retinal thrombosis.
Any one with a family history of cerebral haemorrhage should consult her doctor prior to starting oral contraceptives.
Other side effects include nausea,vomiting,git symptoms,breakthrough bleeding
,spotting,change in menstrual flow,temporary infertility after discontinuation of treatment,oedema,breast tenderness,breast enlargement,breast secretion,change in weight,mood changes,skin troubles etc.these are drug related side effects and cease when medication is discontinued.