Mohammadi, who was arrested in the large city of Mashhad in December, has been on a hunger strike for "at least three days."
She is demanding her right to make a phone call, to have access to her lawyers in Iran and to receive visits, lawyer Chirinne Ardakani told AFP.
The last time Mohammadi spoke to her family on the phone was December 14, according to the lawyer.
The information about the hunger strike comes from another prisoner who has been released.
The 53-year-old was awarded the Nobel Peace Prize in 2023 for her fight for human rights in her home country.
Mohammadi has spent much of the past decade in an Iranian prison. When she was arrested last year, she was on medical leave that had been in place since late 2024.
