Earlier signs pointed to women on the pill having a higher risk of heart disease.
A new look at medical literature, however, found no link between heart attacks and the so-called mini-pills.
The pills include brands like Micronor and Ovrette.
They contain the hormone progestin but not the estrogen of traditional birth control pills.
Experts say the safety of combined contraceptives that include both progestin and estrogen is still a matter of debate.
The study appears in the Journal of Clinical Endocrinology and Metabolism.
