Talcum powder largely consists of a mineral called talc. There have been concerns that particles of talc could travel to the ovaries, cause inflammation, and potentially increase the risk of cancer in the long-term. Although many studies have looked for a possible link between talcum powder and ovarian cancer, their results are inconsistent. In 2006, the International Agency for Research on Cancer looked at all the available evidence and concluded that talcum powder ‘possibly’ causes cancer in people. This is one of their lowest ratings – it means that the evidence is weak and inconsistent, but that we cannot rule out a risk. Several studies have suggested that using talcum powder increases the risk of ovarian cancer by 30 to 60 per cent. However, these studies interviewed women who already had ovarian cancer and asked them to remember whether they used talcum powder a long time ago. Their memories might not have been accurate, and they might have mistakenly thought they used more talc than they did in an effort to explain their cancer. Scientists can avoid these problems by running cohort studies, which follow healthy women over time to see if the talcum powder users are more likely to develop cancer. One such study has been done, and it found no link. There are other reasons to doubt a link between talcum powder and cancer. Studies have generally shown that the risk of ovarian cancer does not go up the more talc women use – you would expect it to do so if the two were truly linked.