The Morning Show host let fans know she experienced a cancer scare after she noticed a spot on her face but left it for 18 months before she opted to seek medical treatment.
Gillies has used the social media platform to warn her 93K followers of the dangers of leaving a skin cancer for too long after learning she had actinic keratosis.
"This is me rocking an Actinic Keratosis. On the left is what it originally looked like. Barely a spot.. so I ignored it for 18 months because I was frightened of what the treatment would be. Stupid," she admitted.
The 50-year-old also noted that the photos were graphic, however, she felt obliged to share the important message with fans.
"I realise the pic on the right LOOKS scary, but that was 2 weeks into treatment. And it was able to be completely covered by makeup," she said.
"I had no days off work. Even on TV."
"I'm sharing these ugly pics so that you know you DON'T necessarily have to get these sunspots 'burnt' off," she continued, before revealing the treatment she underwent.
"My treatment was a cream; a kind of 'chemo' cream. My doctor @drnatashacook realised I needed the solution to be the least invasive possible. If ignored, these spots can turn cancerous so I beg you not to wait..like I did. And now, 5 weeks later? There's not even a mark. Obviously, I'm no expert..just a TV chick..but just worth asking the question of your doctor. 🌞🌞🌞," she wrote.
See the graphic photo below.