This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Methods - Combined Oestrogen-Progestogen Methods, Subject name: Gynaecology & Obstetrics
Amount of estrogen in low dose oral contraceptive pills: 
Select and explain. 
A. 30 micro grams, B. 40 micro grams, C. 50 micro grams, D. 20 micro grams
A: 30 micro grams
Answer: A: 30 micro grams 
Explanation: Ans. is 'a' i.e. 30 micro grams Low dose - 30microgm Very low dose - 20microgram Standard dose 50 microgram When the pill first came out in the 1960s, it had 150 micrograms of estrogen. Side effects were common, and that formula was soon taken off the market. Nowadays, the highest dose available is 50 micrograms of estrogen, but even that is rarely prescribed anymore. Today, most pills have 35 micrograms or less of estrogen, an amount that's generally called "low dose." In recent years there's been a trend toward even lower levels of hormones. "Ultra-low-dose" pills have 20 micrograms of estrogen or less.