I have been taking microgynon30(levonorgestrel, ethinylestradiol) for 3 months. as it was unavailable i started gynera(gestodene ethinylestradiol) 1 month. can i go back to microgynon30 next month, as they don't have the same ingredients.

Safe to switch: It is safe to switch from one product to another. As long as the new package is started on the expected date, there should be no lapse in protection for pregnancy. Gestodene has less androgenic activity that levonorgestrel and improved effects on lipids and BP, but higher spotting/ break through bleeding and a slightly higher risk of deep vein thrombosis that levonorgestrel.

Oral bcp's: Oral bcp's which are called "combination" pills, like the two varieties you mention, can be taken alternatively, as both contain similar hormones. Once the "active" pills are ended with the first type, wait 5 days and start the second type. Make sure you take the active pills the same time each evening, or some "breakthough bleeding" may occur.