Woman says her 3200 boobs are biggest in Britain – and they’re still growing
A 30-year-old East Anglian model says her rapidly growing 32OO chest now eclipses Britain’s self-proclaimed biggest busts, after being diagnosed with gigantomastia following Mounjaro use

Tianna Moon(Image: Tianna Moon / SWNS)

A 30-year-old model believes her breasts are bigger than Melissa Ashcroft’s assets. Ashcroft is notable for claiming she has the biggest breasts in Britain with size 34M.

The model also says her breasts surpasses the UK’s largest, Summer Roberts, who sports a 30M cup. Tianna Moon is now a size 32OO. Tianna Moon, as she’s known online, has a rare condition called gigantomastia, which causes rapid and excessive breast tissue growth.

Moon says she only learned about it last year after taking the weight-loss injection Mounjaro. Since then, she says her bra size has surged from 38M to 34NN.

Additionally, in less than a month she is now measuring 32OO.

She has natural 32OO boobs(Image: Tianna Moon / SWNS)

While she says the condition is painful and she worries how much further her chest could grow, she is trying to find a positive in the situation. “My breasts are much bigger than those claiming the title,” Tianna, from East Anglia, said.

She continued, as the Sun reported: “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.

She suffers from gigantomastia(Image: Tianna Moon / SWNS)

“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.” Growing up, Moon said her breasts have “always” been on the larger side, which meant she attracted “quite a bit of attention” from people her age and older, the Sun reported.

She recalled: “I remember walking home from school as a 13, 14-year-old and it was quite common to have grown men leering at me and honking their horns and stuff.” Moon reportedly launched an adult-content career in 2021 after a head injury meant she could no longer work full-time.

She was diagnosed after her boobs got bigger(Image: Tianna Moon / SWNS)

The model claims she now earns around £10,000 a month from fans of her curvier figure. She said: “I might as well try and reap the benefits of my medical condition rather than the negatives.

“After Covid and furlough I decided I wanted to work for myself and be in charge, manage my own schedule and still make money.” One of Moon’s adult page subscribers eventually urged her to get remeasured, prompting her to start monitoring her breast size as it continued to grow.

After losing weight in 2024 but still seeing growth, she researched it and says she discovered gigantomastia while looking into the less severe condition macromastia. In July 2025, she went to her GP and explained what she’d been researching, as per the Sun.

Moon said: “He was point blank like ‘this is gigantomastia’. I got the diagnosis quite early because of the growth not being common with anything else.”

Moon’s breast tissue reportedly weighs an estimated four stone. It causes daily problems including back and shoulder pain, difficulty exercising and struggling to find clothes that fit.