Assertion: birth control's estrogen | /r/HasProperty | synthetic preparation
Facets:
Source sentences:
text: Unlike estrogen (the synthetic preparation ethinyl estradiol) which is found in various brands of combination pills, there are several different types of progestin which may be used (discussed below.)
text: Hormonal methods use two basic formulas: Combination hormonal methods contain both estrogen and progestin (synthetic progesterone ).