The 44-year-old thanked the pilots for diverting the plane to Omsk, despite a bomb warning that was phoned through to the airport there.
He also credited the airport medical officers and ambulance team who “did not say any lies about diabetes, etc., but immediately clearly said: ‘this is toxic poisoning’ and gave me a dose of atropine.”
Contradictory accounts have emerged of when and where Navalny was given atropine, a drug used to treat nerve agent or pesticide poisonings. Medical experts have said it probably saved his life.
Sources had previously told Reuters that parademics gave him injections, but not of atropine, and that this was administered later when he was admitted to hospital in Omsk.
Navalny was discharged from a Berlin hospital earlier this week and has said he will undertake daily physiotherapy.
The latest Instagram post showed him hugging his wife Yulia and gazing straight into the camera with a neutral expression.
“Thank you, good unknown friends. You are good people,” he said. (Reporting by Maria Tsvetkova and Anton Zverev; Writing by Mark Trevelyan; Editing by Andrew Heavens)