In 1969, journalist and women’s health activist Barbara Seaman published a book detailing the horror stories of women experiencing terrible side effects from the contraceptive pill, including blood clots, heart attacks, strokes, depression, suicide, obesity and loss of libido. After U.S. Senator Gaylord Nelson read the book, he joined forces with Seaman to instigate a series of Senate hearings on the issue. After those hearings, manufacturers were mandated to place inserts in birth control packages warning of possible side-effects, a first for any prescription drug.

Today, the combined contraceptive pill has about a third the dosage of estrogen and about one-10th the dosage of progestin versus the original pills. Yet, health concerns persist.

A bewildering number of studies have been conducted on the pill; in fact, the FDA reports that more studies have been conducted on the potential side effects of the pill than on any other “medicine.” Although some studies have touted positive side effects to taking the pill, such as a decreased risk of ovarian and colorectal cancer, it seems the majority have produced negative results. In one popular study that seemed to reflect well on the pill, researchers claimed it significantly lowers the risk of heart attacks and stroke. They were subsequently forced to revoke the claim, however, when third-party analysis discovered their research was seriously flawed.

One of the top health concerns has been the breast cancer link. At a time when breast-cancer awareness pink seems almost as ubiquitous as climate change green, it remains a little-known fact that the International Agency for Research on Cancer has classified the pill as a Type 1 carcinogen. In 2006, the Mayo Clinic produced a study in which it determined that there is a 44 per cent increased risk of developing breast cancer for pre-menopausal women on the pill before having their first child. To put this finding into perspective, it is worth noting that women are sometimes urged to limit their alcohol intake because of studies indicating that women who consume 2-5 drinks daily have a 1.5 per cent increased risk for breast cancer.

Another study from 2002 concluded that the genetic mutations known as BRCA1 and 2 give women a 33 per cent risk of developing early onset breast cancer if they have taken the pill for five years or more. One out of every 200 Canadian women carry one of these genes.

Studies have also found that use of the pill can increase the risk of cervical cancer or HIV/AIDS in certain women. One study from 2009 drew a line between use of the pill and low birth rates or premature births in subsequent pregnancies.

On the psychological side, oral contraceptives have been shown to decrease women’s libido and sex appeal and even influence their choice of romantic partner. As Marie Hahnenberg of the American Life League-sponsored “The Pill Kills Campaign” points out, the danger with the latter side effect is that a woman on the pill may “fall for” and marry a man, only to find herself no longer attracted to him on going off the pill years later.

Scientists are not the only ones still noticing these negative side effects. An estimated 25,000 lawsuits are being filed in the U.S. regarding the popular Yasmin/Yas birth control pill made by Bayer HealthCare Pharmaceuticals, prompting some lawyers to call it the newest “mass tort.” In a Canadian case, a group of women has recently launched a class action lawsuit against Bayer Inc., with one woman reporting heart palpitations and unusual menstrual changes, including periods lasting as long as 14 days, culminating in a mini-stroke.

Bayer Inc. has not been the only company bombarded with lawsuits. In 2008, the pharmaceutical manufacturer Johnson and Johnson spent at least $68 million to settle hundreds of lawsuits before being forced to recall its Ortho Evra birth-control patch. The lawsuits represented thousands of women complaining of detrimental health effects, including blood clots, heart attacks, and strokes, suffered as a result of using the patch.