More than 10,000 women in France have reportedly contacted the collective Lacrymos de sang, saying they experienced symptoms including severe cramps, early menstruation or heavy bleeding after exposure to tear gas during protests or in other situations. The collective was founded by Eva Luna Tholance on 8 October. Some complaints were said to have occurred within 48 hours of exposure, and some women reportedly required hospital care. A scientific link between tear gas and the symptoms has not been established.

Clinical and forensic toxicologist Eric Franssen said the complaints were serious but cautioned that there is too little research to establish a direct connection. Studies in France and the United States have indicated a possible association, but they relied on voluntary questionnaires and did not medically examine participants; stress and other factors may also affect menstrual cycles. Tholance called for more research and for France to suspend tear-gas use, while Interior Minister Nunez defended its use and said he would not suspend it.