Australian experts are divided over fresh British research that says the oral contraceptive pill is good for women.
The study published in the British Medical Journal says women who have taken the pill are less likely to die from any cause, including all cancers and heart disease, compared with those who have never used it.
The UK researchers followed 46,000 women for nearly 40 years, in what is now one of the world's largest contraceptive pill studies.
Some Australian academics back the findings but others warn the study is flawed and fails to consider the pill's effect on mental health.
Professor Jayashri Kulkarni from the Monash Alfred Psychiatry Research Centre in Melbourne says she is concerned about the size of the study and the conclusions drawn from it.
"There are all sorts of anomalies that worry me," she says.
"Big epidemiological studies that have many flaws such as this one are not predictive in side effects and other effects of medication.
"It will create a lot of interest and excitement, but won't be helpful for individual women as it is not designed for that.
"The study results could give the false impression that the pill somehow decreases cancer when in fact the finding may be due to the loss of follow up of women who actually died from clotting problems on the pill."
Kulkarni says while the study addresses the pill's physical impact it is also important to look at how the pill influences women's general wellbeing.
She has spent years researching the link between oral contraceptives and depression in Australian women.
"We have been very concerned about the impact of the progesterone component of the pills that are most commonly used, in that progesterone seems to have a depressive effect and many women describe an insidious, slow onset of depression," she says.
"That's not something that's significantly looked at in research studies.
"The studies focus on physical wellbeing, but in fact it's the mental wellbeing that really is the biggest contributor to women deciding to go off the pill or change pills."
The UK study did find a higher rate of violent death, such as suicide, among pill users.
Protects against cancer
But Professor John Hopper from the University of Melbourne's School of Population Health believes the pill can be beneficial for women and says he has found it can protect against cancer.
In a recent study he found that women with mutations in genes BRCA 1 and BRCA 2 - which places them at a higher risk of developing breast and ovarian cancer - may in fact be protected by the pill.
"We'd been conducting studies of women with mutations in those genes to find out what might increase or decrease risk for those women," he says.
"We had the hypothesis that use of oral contraceptions would actually be bad for these women.
"To our surprise, we found that for women who had a mutation in BRCA 1, the data was telling us that if they used oral contraception they may be protected from ovarian cancer.
"So for women with a certain high risk of breast cancer, the pill might actually be protective against breast cancer and ovarian cancer."
Hopper admits there is research which shows increased risks for women who take the pill, but says oral contraception has come a long way since it was introduced in the early 1960s.
"Although there might be reports of it having side affects... now, in the longer term, you have bigger studies and you may be getting a better answer than what you were at the time when it [the pill] first came out," he says.
"There were problems with the pill, they seem to have been addressed. We've got to keep on monitoring these things, but it may be surprisingly protective for some women and this could be an important finding."
Kulkarni says there need to be more well-designed trials of different pills so that women and their doctors can determine the best oral contraceptive for them.
"The pill is a significant, empowering development for women and the next important step forward is the further development of an effective contraception with optimal physical and mental health safety," she says.
While the British study did find a slightly higher risk in women under 45 years of age who are current or recent users of the pill, the researchers found that the effects in younger women disappear after about 10 years and the benefits in older women outweigh the smaller excess risks among younger women.