Not beyond judicial review, but not under the purview of the SCOTUS.

They aren't under the purview of SCOTUS. The lower courts are.

Their only purview is the legality of laws and rulings.

That's exactly what they're doing here. A lower court ruled that the FDA didn't follow it's own process when relaxing restrictions around the prescribing and dispensing of mifepristone. The loser appealed and the next highest court ruled that the FDA did follow its own process. Repeat appeals until you reach SCOTUS who is now ruling on which of the lower courts is correct. That's it.

SCOTUS is NOT ruling on whether mifepristone is legal or approved for use, it's ruling on whether a lower court followed the law when reaching its decision and whether or not that decision is consistent with the Constitution. In practical terms whichever way SCOTUS rules it's those lower courts whose authority will be used to direct (or not) whatever the FDA does next.

This is fundamentally judicial overreach, as is about 90% of everything they have done this last couple years.

You see so much as "Judicial Overreach" for two reasons:

1. You don't understand the process.
2. So much of what gets to court, including SCOTUS, these days are questions of Administrative Law because much of this country is being run by Administrative Law. Which is what this case is about.

Most of what is decried as "Judicial Overreach" should more correctly be called AGENCY Overreach but its being blamed on the Judiciary.

Like this case. The problem isn't SCOTUS it's the agency known as the FDA.

The Supreme Court has no authority to "rule" on the constitutionality of laws. They took that power for themselves (Marbury v Madison) and nobody called them on it. They've now decided that the constitution isn't comprehensive and they must also consider the customs and traditions of the nation (and even before) when they come to a decision. Dangerous times.

Making a decision about the legality of medication is judicial overreach.

That isn't whats happening. What's going on is that the FDA is being challenged that it didn't follow it's own process on approving the relaxation of rules regarding the prescribing and dispensing of Mifepristone. If SCOTUS rules that they didn't follow their process mifepristone will still be available but will return to being harder to get...at least until it DOES follow its own process.

That's a rightwing lie about what the Court is supposed to do. The high court may rule on appeals from the state's highest court's decision and any federal court's decision. Virtually all modern First Amendment freedom is ”courtmade law,” likewise for the Fourth, Fifth, Sixth, Seventh, Eighth, Fourteenth. Miranda rights are "court made," exclusionary rule.

Conservatives love it too. They love them some court made "government contractor defense," in which the originalst textualist Justoce Scalia extended the federal government's sovereign immunity to defense contractors based on no statute or constitution.

Scotus isn't being called to pass upon the legality of medication, it is being called to pass upon the legality of the federal substantive and procedural due process given to stakeholders in the administrative rulemaking process. It's very much a constitutional issue, insomuch as due process, notice, and comment, are prerequisites to Constitutional due process. Sort of seems like you don't know what you're talking about.