A 30-year-old model from East Anglia asserts that her 32OO breasts represent the largest natural assets in Britain, surpassing those of competitors like Melissa Ashcroft’s 34M and Summer Roberts’ 30M.
Rapid Growth from Rare Condition
Tianna Moon suffers from gigantomastia, a rare disorder triggering excessive breast tissue expansion. She discovered the condition last year following weight-loss treatment with Mounjaro. Her bra size escalated from 38M to 34NN, reaching 32OO within a month.
Moon expresses concern over ongoing pain and potential further enlargement but seeks optimism. “My breasts are much bigger than those claiming the title,” she states. “I’m running out of alphabet at this point. I am genuine; unlike a lot of other people claiming the title. Many of those who claim to have the biggest breasts involve cosmetic enhancement or rely on US bra sizing alone. My situation is different as my chest growth is entirely natural. I just let my boobs do what they want. Although I do hope they stop at some point. If anybody is bigger than me, I’d love to meet them.”
Early Challenges and Attention
From a young age, Moon’s breasts drew significant notice. As a 13- or 14-year-old walking home from school, she frequently encountered leering from grown men, including horn honking.
Career Shift to Adult Content
A head injury in 2021 ended her full-time work, leading Moon to launch an adult content career. She now earns approximately £10,000 monthly from subscribers attracted to her figure. “I might as well try and reap the benefits of my medical condition rather than the negatives,” she explains. “After Covid and furlough, I decided I wanted to work for myself and be in charge, manage my own schedule and still make money.”
A subscriber prompted her to remeasure, spurring ongoing tracking. Despite 2024 weight loss, growth persisted, leading her to research macromastia and identify gigantomastia. In July 2025, her GP confirmed the diagnosis immediately due to its distinctive progression.
Daily Struggles
Estimated at four stone, her breast tissue causes persistent back and shoulder pain, exercise limitations, and clothing fit issues. Moon often skips bras due to scarcity and discomfort in suitable sizes, complicating sleep from the weight.
