Periods, or cycles, were a biological phenomenon involving blood experienced by some beings that could be managed using suppressant shots and painkillers. Periods could be unpredictable, inconvenient, or painful. Some of the Royal Naboo Security Forces, Queen Padmé Amidala, and the group of teenage human females who served as the monarch as her handmaidens, had cycles.
In 32 BBY, the handmaiden Sabé acted as decoy for Amidala's first public appearance as queen when the monarch was temporarily incapacitated due to an unexpected and painful period and needed to take painkillers. The same year, the handmaiden Saché experienced her first cycle, which triggered the blood alarm's blood-sensitive sensor in Amidala's palace apartment. Sabé later recalled the incident in 22 BBY, remembering Captain Quarsh Panaka's horror about why the alarm had been triggered. During the Imperial Era, the Partisan Idryssa Barruck talked to the human girl Jyn Erso about personal health and hygiene.
Periods, also called cycles, were a biological phenomenon experienced by some beings—including humans—on a cyclical basis. The onset of a period could be detected by sensors sensitive to blood. Some beings kept absorption pads in their bathroom as an option to use, while others took suppressant shots to avoid having cycles. Periods could cause beings to experience pain or cramps of varying severity that could be relieved by painkillers.
During the Republic Era, several Naboo with periods on the Mid Rim planet Naboo used suppressant shots to manage them, including some of the Royal Naboo Security Forces. By 32 BBY, Queen Padmé Amidala and some of the teenage human females who served as her handmaidens experienced cycles. The girls resided in an apartment within the Theed Royal Palace together and kept absorption pads in their bathroom for their periods. During Amidala's first public tour that year, she was caught off guard when she failed to anticipate the start of an unusually painful period. Her handmaiden Rabé expressed surprise that Amidala was not using suppressant shots. Fellow handmaiden Yané attributed Amidala's experience to increased stress and made a note on the queen's medical profile for the droids to address this when they returned to Naboo's capital, Theed. The monarch's decoy, the handmaiden Sabé, appeared publicly as the queen while Amidala waited in bed for her painkillers to take effect.
Not long after, officer Mariek Panaka and her husband, Captain Quarsh Panaka, were alerted by a blood-sensitive sensor in Amidala's palace suite that someone was bleeding. They discovered the twelve-year-old handmaiden Saché, who was unaware she had started her period, in bed sleeping. Mariek helped a mortified Saché acquire new sleeping garments and bedding as the handmaiden left to clean up. The officer then berated Quarsh for installing a blood-sensitive sensor in a bedroom occupied by teenage girls, telling him that the older handmaidens likely utilized suppressants as she and other guards who cycled did. After Amidala and her other handmaidens returned to the palace from a concert, Saché mentioned she had ruined a bedsheet and commented on her colleagues' glitter-covered state, causing the queen to laugh. Years later, in 22 BBY, Sabé reminisced about the Saché incident and Quarsh's horror upon realizing why his blood-sensitive sensor's alarm had been triggered.
At some point between 13 BBY and 6 BBY, after the human girl Jyn Erso joined the rebel leader Saw Gerrera's Partisans, Gerrera recruited a fellow Partisan—the woman Idryssa Barruck—to have a private conversation with Erso about her health and hygiene.
Periods were first mentioned, albeit indirectly, in the 2017 young-adult novel Rebel Rising by Beth Revis. According to Star Wars author E. K. Johnston, Revis was asked by fellow Star Wars author Jason Fry to include a plot device within Rebel Rising to demonstrate that Saw Gerrera was ill-equipped to parent a young Jyn Erso. As a result, the novel contained an indirect mention of the concept via a discussion "about hygiene and health." Periods were first identified by name and made their first full appearance in the 2020 young-adult novel Queen's Peril, written by Johnston.
Johnston liked the concept and attempted to include periods in her 2019 young-adult novel Queen's Shadow. However, she was ultimately unable to find a good way to introduce the idea due to the installment's characters being past the age when cycles often began. The author instead decided to include periods in Queen's Peril because the handmaidens featured in the work were slightly younger. During the novel's development, several members of Lucasfilm Story Group—including several of the group's women and Pablo Hidalgo—felt that the scene in which Saché has her first period was extremely awkward and left comments on the work's draft after reading it.
Johnston felt it was important to illustrate that stressful life changes—such as Amidala's election to queen—could affect cycles, while also showing that the handmaidens treated the queen's brief incapacitation as something that happened to everyone on occasion. In Queen's Perils acknowledgments, Johnston gave praise to editor Jennifer Heddle for her work on the book, going on to thank her for helping to ensure that a page on menstruation would be created for the free-to-edit, unofficial online Star Wars encyclopedia known as Wookieepedia. Johnston later expressed her happiness that an article had indeed been created, indicating that she was proud it had come to fruition.