The former A Place In The Sun presenter - who announced in November 2022 he has terminal lung cancer - admitted he is feeling frustrated as he awaited scan results to find out just how much his tumours have grown.
Irwin, 49, told his 218k Instagram followers: "The wait for more scans is frustrating when you know the cancer is on the move again.
"Meanwhile there’s stuff I can do to make the terrain as tough as possible for growth and the ladies down at @sereniti_health are part of my team of suppliers for various therapies. I’d recommend this place to anyone wanting to tap into a healthier lifestyle. Big shout as always goes to @how_to_starve_cancer who’s constant help has a huge impact. #respect"
The TV presenter was given six months by doctors to live back in 2020 and kept his diagnosis a secret from TV producers because he feared losing his job.
He has previously spoken about adopting a special diet in a bid to "starve" his tumours and slow their growth, as advised by cancer survivor Jane Mclelland author of a book called How To Starve Cancer.
The Escape To The Country star - who is parent to four-and-a-half-year-old Rex and three-year-old twins Rafa and Cormac with his wife Jess - recently admitted he was feeling unwell, but continues to make the most of the time he has left with his family.
Irwin is currently undergoing palliative care for his incurable cancer which has spread to his brain.
The TV presenter has previously said doctors did not expect him to see 2023.
He has updated fans throughout the summer with photos of himself making the most of time with his family, including wife Jess.
Irwin kept his diagnosis a secret for two years, and when he told producers of the Channel 4 holiday property show he had terminal cancer, he was dropped because he was told they were unable to insure him to work.
He said he felt "thrown on the scrap heap".
Chemotherapy and cancer drugs have helped extend the initial prognosis and the TV presenter is determined to make the most of any time he has left with his family.
Irwin told BBC's Morning Live in July: "I'm really good. I have up days and down days, but today's very much an up day. The family are great and very noisy."
In July Irwin revealed that he has been receiving palliative care for the past three years, insisting that hospice care did not have to mean "doom and gloom".
Irwin attended the TRIC Awards in June and said: "I wanted to show that because you have cancer it doesn't mean you are a different person.
“You can still work. Look at me now. I don't think the doctors were expecting me to make 2023 but here I am and I'm available at work."
Watch: Jonnie Irwin says being in palliative care does not have to mean 'doom and gloom'