Luigi Mangione Supporters Fawn Over New Haircut

Luigi Mangione was back in court Thursday morning for another extradition hearing ... and his admirers lost their minds 'cause he's cleaned up with a shave and a haircut.

Here's the deal ... Mangione formally waived extradition after he arrived at a Pennsylvania courthouse under heavy security -- he's been officially charged in NYC with the murder of UnitedHealthcare CEO Brian Thompson.

Video captured Mangione being led into the courthouse -- and he appeared to be more subdued than last time, when he lashed out at cameras shortly after he was apprehended.

Supporters of Luigi -- who have seen him as a folk hero pretty much from the moment the cold-blooded midtown Manhattan shooting occurred -- took to X where they fawned all over what looked like a fresh cut and a shave.

Protestors both for and against Luigi on Thursday held signs outside the courthouse ... some calling him the obvious villain ... while others demonized the insurance industry.

This week, Manhattan D.A. Alvin Bragg announced Mangione's indictment, calling Thompson's murder “a killing that was intended to evoke terror."

Mangione is also reportedly facing federal criminal charges related to the Thompson slaying, but that indictment remains sealed for now.

A rep for the Pennsylvania Department of Corrections tells TMZ ... Yesterday, Mangione did visit the barber shop at SCI Huntingdon, the facility where he was held.