Kremlin critic Alexei Navalny has been removed from a medically-induced coma and is responding to speech, Berlin's Charite hospital has said in a statement.
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 her government has concluded Navalny was poisoned with Novichok, the same substance that UK authorities said was used against a Russian double agent and his daughter in an attack in England in 2018.
Russian officials say they have seen no evidence he was poisoned.
The incident has put the future of Germany's Nord Stream 2 pipeline with Russia in doubt as a growing number of politicians call for support for the project to be withdrawn unless Russia helps to clear up the circumstances around Navalny's poisioning.
Merkel's spokesman said on Monday she does not rule out imposing sanctions on the pipeline in response to the suspected poisoning.