Women who smoke may have heard that they shouldn’t be taking birth control pills that contain estrogen. But while doctors recommend that women either find different pregnancy prevention alternatives (i.e. pills/ birth control methods not containing estrogen) or quit smoking before taking estrogen- containing birth control pills, studies find that 80% of women will still continue to smoke while taking the pill.
Smoking and the use of oral contraceptives featuring estrogen each have their own side effects, both relating to blood flow.
While normal blood vessels are softer and more pliable, smoking causes blood vessels to constrict, which overtime results in blood vessel walls becoming weaker and harder. Smoking also increases the development of plaque formations which further contributes to the restriction of blood flow.
On the other hand, birth control pills containing estrogen thicken the consistency of blood, making it easier for blood to clot.2 Combined, the effects of smoking and taking combined birth control pills may significantly increase the risk of serious heart and blood vessel problems, including death from heart attack, blood clots, or stroke. This risk increases with age and the number of cigarettes smoked.
For this reason, all birth control pills containing estrogen carry a boxed warning especially for women over the age of 35 who smoke (see below).
any side effects?
The synergistic effect of smoking and taking combined pills may lead to an increased risk of adverse effects on a woman’s heart and blood vessels, leading to cardiovascular complications such as a heart attack, blood clots, and stroke.
Who is at risk of developing complications?
Women who smoke and are over 35 years old have the highest risk of experiencing cardiovascular side effects when also taking birth control pills with estrogen.3 They should speak to their doctor about alternative birth control methods.
What are some birth control alternatives for women who smoke?
For women who smoke over 15 cigarettes a day, in addition to the combined pill, doctors also do not recommend the patch or ring as these options all contain estrogen. Instead, ask about progestin-only pills or other birth control methods that are estrogen-free, like a copper IUD. Neither of these options contains estrogen.
Why are progestin-only birth control pills safer for smokers?
Progestin-only pills (or POPs) do not contain any estrogen and therefore may have a lower risk of side effects when compared to combined pills in women who smoke. Doctors typically recommend estrogen-free contraceptives for women who are smokers, have high blood pressure, are overweight, suffer from migraine headaches, or have a history of blood clots.
