The widespread usage of the abortion medication mifepristone has been temporarily halted due to an order from a federal judge in Texas.
An hour later, however, a Washington state judge delivered a conflicting judgement, mandating that access to the medicine be maintained in 17 states.
Abortions with the pill have been legal for over 20 years.
The conflicting court orders increase the likelihood that the case will be heard by the Supreme Court of the United States.
Judge Matthew Kacsmaryk of the United States District Court in Amarillo, Texas, froze the FDA's approval of mifepristone in a 67-page ruling. The government has seven days to file an appeal, so the verdict won't take effect until then.
On Friday night, the US Department of Justice announced that it would file an appeal of the Texas decision.
Millions of American women may have less of a chance of getting the medicine if Judge Kacsmaryk rules against the manufacturer. It has been predicted by legal experts that this decision could shake the foundation of the United States' drug regulating system to its core.
The Supreme Court's decision last year to strip abortion's constitutional safeguards has led to a wave of prohibitions at the state level.
In a lawsuit, opponents of abortion claimed the drug's safety hadn't been adequately investigated.
According to Judge Kacsmaryk's decision, the FDA's clearance ran afoul of federal regulations permitting expedited approval of certain medications.
Mifepristone was approved in 2000 after a four-year assessment by the Food and Drug Administration.
The judge added that the FDA ignored mifepristone's "psychological effects" and safety record.
Georgia State University assistant professor of law Allison Whelan, who argued in favour of maintaining FDA approval, called the verdict "inflammatory" since it consistently refers to "unborn humans" rather than foetuses.
She told the BBC, "the inflammatory anti-abortion language used throughout the opinion could not make clearer the politics and ideology motivating Judge Kacsmaryk's decision."
"He cherry-picks the studies he cites to support his conclusion that abortions are unsafe or harm those who get abortions, without citing the many studies that refute those conclusions."
The conservative Christian legal advocacy group Alliance Defending Freedom, which represented the plaintiffs in the action, hailed the Texas decision as "a significant victory" for women and doctors.
March for Life president Jeanne Mancini welcomed it as "a major step forward for women and girls"
In contrast to the Texas judge's decision, a federal judge in Washington state issued a rival 31-page injunction on a separate case, instructing the FDA to keep the medicine on the market in the Democratic-run states that launched the action, an hour after the Texas judge's verdict.
Bob Ferguson, the state's attorney general, referred to the reversal as a "huge win."
In response to the Texas ruling, Massachusetts Democrat Senator Elizabeth Warren tweeted, "We can't let one right-wing extremist overrule women, their doctors, and the scientists."
Mifepristone, one half of an abortion-inducing duo, terminates the pregnancy, while misoprostol, the other half, empties the uterus.
Initially, it could only be used to end pregnancies up to seven weeks along.
In 2016, its safe use during pregnancy was increased to 10 weeks.
In addition to its usage in abortion, mifepristone is frequently prescribed to women with Cushing syndrome or a history of miscarriages.
The Democratic governor of Washington state said last week that the state had stored enough mifepristone for three years in case medicine suddenly became unavailable across the country.
A few days later, Idaho's Republican governor signed a bill into law criminalising the "trafficking" of abortion services. Adults who assist minors in leaving the country for obtaining an abortion without parental permission violate the law.
