Kremlin critic Alexei Navalny has been removed from a medically induced coma and is responding to speech, Berlin's Charite hospital said in a statement on Monday.
The hospital, which has been treating Navalny since he was airlifted to Germany for treatment after falling ill on a Russian domestic flight last month, said he is being weaned off mechanical ventilation.
"It remains too early to gauge the potential long-term effects of his severe poisoning," Charite said in a brief statement.
German Chancellor Angela Merkel has said Berlin has concluded Navalny was poisoned with Novichok, the same substance that Britain said was used against a Russian double agent and his daughter in an attack in England in 2018.
Moscow says it has seen no evidence he was poisoned.