On January 1, Twitter was buzzing, not with New Year’s Day resolutions or football fans cursing their college teams, but a viral post that suggested that every sexually active American — man or woman — stock up on the emergency contraceptive Plan B before Donald Trump took office.

The response was split. Suggestions that Kelly Ellis — the woman who had posted the initial tweet in response to California legislation allowing people to purchase a year of birth control at a time — was unworthy of having children in the first place stacked up. Retweets multiplied. And Ellis’s sentiment gained traction outside of California: With millions concerned that a Republican Congress could repeal the Affordable Care Act, including its Contraception Clause, and halt the over-the-counter sale of FDA-approved emergency contraceptives, including Plan B and its newer iteration ella, Ellis’s advice made political sense. But did it make scientific sense?

Before Kelly Cleland, a researcher at Princeton University’s Office of Population Research and the founder of the American Society for Emergency Contraception, dives into the science, she’s eager to point out that the ACA was successfully designed to give women access to family planning, including birth control and emergency contraception — otherwise known as the “morning after” pill or Plan B — for being used in a situation where a condom wasn’t used or broke. “It was a game changer in allowing women to have birth control without having to pay for it,” she said. And that made a difference: Abortion rates have fallen to their lowest rate since Roe v. Wade to 14.6 abortions per 1,000 women from a high of 29.3 abortions per 1,000 women in 1980; average ages of first birth have climbed to 26.3 years old in 2014, making teenage mothers increasingly uncommon.

The biochemistry of Plan B is more difficult to parse than its socioeconomic effects. It’s a progestin-only contraceptive, which means that it does three things to halt the egg fertilization process: block the ovary from dropping an egg, stop the sperm and egg from meeting, and prevent the fertilized egg from attaching to the uterine wall.

“It’s an incredibly safe, really medically benign product that went through many regulatory steps considering how safe it is,” Cleland says.

It’s not, she repeats, the same as medically inducing an abortion. Emergency contraception acts to block an egg from being fertilized — in other words, from stopping a woman from getting pregnant in the first place. Abortions, on the other hand, require a woman to be pregnant, as it is a termination of a pregnancy — in other words, by this time, the egg has been fertilized and begun developing as a fetus. (Importantly, emergency contraception has a declining rate of efficacy with each passing hour and is not as effective as a condom or birth control for blocking fertilization, with a 65 percent success rate compared to a condom’s 98-99% success rate.)

There’s no reason to believe, however, that emergency contraception would “go bad” in the next four years. Cleland said that the FDA testing on birth control is held to a higher standard than most other over the counter medicines, and the sensitive social nature of emergency contraception has made Plan B and its generics among the drugs most likely to remain efficacious for the length of the Trump administration. Biochemists at the National Institutes of Health, which tested the molecular basis of Plan B, would not speak on the record, but the fact that the FDA put Plan B through the ringer should comfort hoarders.

But will it be necessary? That depends on where people live— and on James Barrickman.

James Barrickman launched Afterpill for a demographic of women who are isolated economically, socially, and geographically and in desperate need of emergency contraception. Plan B isn’t cheap — depending on where a person lives, it can cost about $40 to $50. Women and girls who have pre-marital sex may be stigmatized, and mom-and-pop pharmacies in small towns may be uncomfortable, risky settings for purchasing emergency contraception.

Barrickman said this demographic of women — and their male partners — fall through the cracks: They need Plan B fast, but are in a sticky spot between economics and social appearances. His mail order startup sells generics directly to the consumer discreetly, cutting costs to $20 a pill — no insurance necessary.

Business is booming for Barrickman, who says that there aren’t any specific regional patterns he’s noticed, though there are seasonal spikes around New Year’s and Valentine’s Day. “But we’ve noticed that about 15 percent of orders come from men,” he noted. That could be because women are ordering through a partner’s credit card, but it’s worth noting that Plan B isn’t just an issue solely for females.

Cleland’s research shows that use of the Afterpill service and current purchasing patterns of emergency contraception might actually represent the maintenance of the status quo. People often don’t buy emergency contraception using insurance because it’s (usually) a spur of the moment decision. “I don’t think there’s going to be much of a change, actually,” Cleland said. “Most women buy [EC] without insurance anyways — it’s over-the-counter and you don’t need a prescription, so many women don’t think to use insurance for it.”

The only real difference would be bulk purchasing. By nature of the fact that Afterpill doesn’t do instantaneous shipping, Barrickman said his startup’s entire premise relies on customers stocking up — and they do, enthusiastically.

As for whether congressional action could result in a reverse in FDA rules, Cleland is skeptical but concerned. “Nothing is impossible, of course, but it’s never happened,” she says. “It could only be reversed for a major safety reason. But for politics or morality — there’s no real precedent.” What Congress could potentially do is make it legal for people to refuse to provide Plan B.

“We might be heading into a climate where people feel emboldened to impose their view on others,” Cleland warned. “Most EC [emergency contraception] is sold in pharmacy chains, and chains have a policy at the corporate level to provide EC.” But no one is regulating mom-and-pop chains, and there’s a significant chance that smaller drugstores, more common in small-town middle America, would opt out for religious reasons.

Being refused emergency contraception means delaying consumption and therefore puts a woman at an increased risk of pregnancy. In towns that are small, rural, and isolated, it’s even harder for women to get abortions. Cleland says these are the places that might want to take a doomsday prepping approach.

“I highly endorse stockpiling emergency contraception right now, man or woman,” Cleland said. “It’s important, because women may have less ability to do so, especially without insurance, and as abortion rights get more restrictive, it makes getting EC fast all the more important.”

Photos via Flickr / anqa