Nearly 40 years later, Steinem’s essay still stings because “menstrual equity” has gone almost nowhere. Today, tampons and pads are taxed in most states while adult diapers, Viagra, Rogaine and potato chips are not. Men can walk into any bathroom and access all of the supplies they need to care for themselves: toilet paper, soap, paper towels, even seat covers. Women, however, cannot. In most schools, girls have to trek to the nurse’s office to ask for a pad or tampon, as if menstruating is an illness rather than a natural function. In most public and private places, women are lucky if there’s a cranky machine on the wall charging a few quarters for a pad that’s so uncomfortable you might prefer to use a wad of rough toilet paper instead. No change? You can pay for a parking spot with a credit card, but have you ever seen such technology on a tampon machine in a women’s bathroom? The situation for prison inmates and homeless women is far direr.

Even if you do have access to tampons, the Food and Drug Administration (FDA) does not require companies to list the ingredients—yet the average woman has a tampon inside her vagina for more than 100,000 hours over her lifetime. Tampons may contain “residue from chemical herbicides,” says Sharra Vostral, a historian at Purdue University who wrote Under Wraps: A History of Menstrual Hygiene Technology. “We do not really understand the health consequences, because we are not testing for them in relation to tampons.”

If all this sounds unfair, try getting your period in the developing world. Taboos, poverty, inadequate sanitary facilities, meager health education and an enduring culture of silence create an environment in which girls and women are denied what should be a basic right: clean, affordable menstrual materials and safe, private spaces to care for themselves. At least 500 million girls and women globally lack adequate facilities for managing their periods, according to a 2015 report from UNICEF and the World Health Organization (WHO). In rural India, one in five girls drops out of school after they start menstruating , according to research by Nielsen and Plan India, and of the 355 million menstruating girls and women in the country, just 12 percent use sanitary napkins.