A new workplace standard has been created to help businesses support employees experiencing menopause or menstruation.
It comes after research from the Fawcett Society suggested about 10% of those experiencing menopause have left the workplace due to symptoms such as hot flushes, dizziness, insomnia, and muscle and joint stiffness.
The figure is as high as 25% for those with more severe symptoms.
The British Standards Institute (BSI) has published a new workplace standard - which recommends workplaces consider whether there is a general awareness of menstruation and menopause in their culture.
It also recommends training for line managers and HR workers, and that women have opportunities for open conversations or to request support.
Anne Hayes, director of sectors at the BSI, said: "Organisations which prioritise their people by building an inclusive workplace will be best placed to continue to thrive in the future.
"There is no one-size-fits-all experience of menopause, but the data suggests thousands of women are leaving the workforce at this stage, contributing to significant productivity losses, robbing organisations of talented people, and removing mentors who can draw on their experience to support newer members of staff.
"It doesn't have to be that way."
The new workplace standard - known as BS 30416 - has been developed with the help of companies including supermarket chain Morrisons and telecoms firm BT.
Unison, the LGBT Foundation, the Institution of Occupational Safety and Health, the Daisy Network and Endometriosis UK have also contributed to the guidance.
Helen Tomlinson, menopause employment champion for the UK Government, said: "I am truly delighted that the BSI have produced the Menstruation, menstrual health and menopause in the workplace standard, recognising the challenges, symptoms and experiences of both menopause and menstrual health and how these can affect women in the workplace.
"It's a free resource for any organisation, large or small across all sectors, to be able to utilise. This will go a long way to ensure that everyone can receive the support they need at this critical time."