New guidelines for how police treat female detainees with their periods have been proposed by the Home Office.
Ministers are consulting on plans to change codes of practice in England and Wales to ensure women in custody are treated with dignity.
The review comes after a watchdog suggested earlier this year that police were "routinely ignoring" the needs of women on their periods.
The government said everyone in custody should have "their needs respected".
The Independent Custody Visiting Association (ICVA) - which monitors the treatment of detainees - had warned that women were often held in police cells without access to hygienic sanitary protection or facilities for washing and changing.
It said the treatment by police could be in breach of human rights and equality laws.
Under the government proposals forces will be required to:
- Ask female detainees at the earliest opportunity if they are likely to require any sanitary products while in custody
- Make them aware these products will be provided free of charge
- Ensure all female detainees can speak to a female member of staff if requested
- Consider the dignity of menstruating detainees
Policing minister Nick Hurd added: "Our proposals should leave forces across the country in no doubt of their responsibilities towards women in custody."
Evidence gathered by the ICVA suggested the problem of sanitary provision was widespread across forces in England and Wales.
ICVA chief executive Katie Kempen welcomed the consultation, adding that the proposals were "a significant step forward in ensuring that the dignity of female detainees is upheld in police cells".
A National Police Chiefs' Council spokeswoman said it was working with the College of Policing and women's groups to ensure forces have the right guidance to help them meet the needs of women in custody.
She added: "We were concerned to hear a small number of women in police custody weren't able to access sanitary products."