Unexpected Breast Growth Amid Weight Loss Journey

A woman, Tianna Moon, found herself perplexed after experiencing significant breast enlargement even as she lost five stone with the aid of Mounjaro, a weight-loss medication.

At 30 years old, she’s contemplating breast reduction surgery to address her 34NN size but is aware that this might not prevent further growth.

In the UK, those wanting breast reduction surgery on the NHS face strict requirements. They often receive guidance to attempt weight loss before considering surgery. Approval hinges on whether large breasts cause physical discomfort, like back or neck pain, skin irritation, and more. Additionally, applicants must have a Body Mass Index (BMI) under 26 and demonstrate an expected reduction of 500 grams in breast volume.

Tianna, who weighed 19 stone when she initiated her weight loss journey in May 2024, cited her breast size as the reason for her decision—finding bras practically non-existent in her size. Instead, she had to settle for the largest sizes available, an experience that led to cuts and infections under her ribs.

She mentioned that she’s always had a larger chest, which attracts a lot of attention. Over time, this scrutiny has become so normalized for her that it barely registers now, though she tries to minimize their appearance in public. Stares and double takes are just part of her daily life.

Nearly two years ago, Tianna began taking Mounjaro and managed to lose three stone in the first year, followed by another two stone subsequently. Interestingly, while her waistline became smaller, her bust continued to expand, moving from an L cup to a size she found rather odd—M cup.

Dealing with such voluptuousness comes with its challenges. Tianna described suffering from issues like numbness in her arms and severe shoulder indentations, along with light scarring from bra friction. Lying on her back has also become difficult due to restricted airflow.

In July of last year, she consulted her GP after researching the reasons behind her ongoing breast growth. The diagnosis was gigantomastia, a rare condition that leads to excessive breast tissue growth. Tianna explained that after detailing her medical history and the effects she was experiencing, her doctor promptly identified her condition.

She received the diagnosis early because her rapid breast growth was atypical. Following this, she decided to shed additional weight to alleviate pressure on her back.

While the specific causes of gigantomastia remain uncertain, health experts suggest it may be linked to hormonal changes, certain medications, autoimmune issues, obesity, or genetic factors.

In response to her diagnosis, Tianna was referred for physiotherapy and chose to undergo a gastric sleeve procedure privately in November 2025 to mitigate pain and safeguard her back.

More recently, she has been exploring breast reduction surgery options but has been warned that there are no guarantees against future growth.

In 2021, Tianna took a proactive approach by joining OnlyFans after a head injury prevented her from working full-time, and her breast size has attracted a substantial number of subscribers. She reveals that she earns up to £10,000 a month from the platform. Interestingly, one subscriber encouraged her to investigate the growth of her breasts despite her weight loss, prompting her to monitor her size carefully.

“I thought I might as well take advantage of my situation in a positive way rather than dwelling on the negatives. It was actually a subscriber who suggested that I get remeasured because my size was inconsistent,” Tianna reflected.