A woman with 34NN breasts discovered she had a rare condition after her breasts grew bigger when she started taking Mounjaro. Tianna Moon, 30, suffers from gigantomastia – a rare condition which causes rapid breast tissue growth. She has "always" had a larger chest and decided to lose weight using Mounjaro in May 2024. She lost three stone but found it "odd" when her breasts grew from an L cup to an M cup - rather than getting smaller as she did. Tianna researched the condition online on