Hormonal birth control pills are probably not responsible for high increase in weight, according to the international scientific network Cochrane Collaboration.
The non-profit organisation came to this conclusion after comparing different studies on birth control methods.
In a statement referring to the analysis, Germany's Institute for Quality and Efficiency in Health Care (IQWiG) said if oral contraceptives had a strong impact on weight, it would have been evident in the study.
However it couldn't be excluded that there might be individual cases of weight gain.
If a woman believes there is a link between her gaining weight after starting to use hormonal birth control pills, she should consult her gynaecologist and ask for an alternative.
Those alternatives could include a different combination or lower dose of hormones, or other types of hormonal contraception like patches and vaginal rings. Also possible are non-hormonal contraception methods like chemical suppositories or barrier methods like condoms or diaphragms.