Flesh-n-Bone Warns Nelly About Drugs Following Gangsta Boo's Death

Flesh-n-Bone is proudly sober these days, and wants his fellow rappers to follow suit, which is why he's sending Nelly a message ... just in case his recent show was fueled by illicit substances.

We caught the Bone Thugs-n-Harmony staple at LAX, and he sounded genuinely worried about Nelly following his now-infamous performance in Australia -- y'know, the one where his eyes were rolling in the back of his head!!!

Flesh tells us he's several months free of alcohol and marijuana, and advises Nelly to be careful on the road, as drugs are now commonly being spiked with fentanyl.

We should say, there's no proof Nelly was taking anything ... nor has he said a peep about the rumors.

Flesh's newfound sobriety might shock longtime Bone Thugs fans -- the group sold millions of records, and is credited for "classic" hip hop weed anthems like "Buddah Lovaz." They even lovingly serenaded ecstasy back in 2000.

He calls it a necessary change ... revealing longtime Bone Thugs' producer DJ U-Neek lost 2 sons to overdoses, and also reflected on Gangsta Boo’s death ... which is also suspected to be OD-related.

Flesh remembers GB fondly as a rockstar and says his Bone Thugs brothers deserved the "tongue-lashing" she dished out after they started a fight during their 2021 Verzuz battle with Three 6 Mafia.

Bone Thugs and Three 6 were able to grow tighter after the brawl -- and Flesh says the Memphis rap legends contacted them personally to deliver the unfortunate news their First Lady had passed.