PLEASE DON'T TRY THIS AT HOME! This is highly experimental and incredibly dangerous stuff.
Estradiol by itself doesn't stimulate breast development. IGF-1 acts in concert with estradiol to build breast tissue and determine final breast size. In essence, estradiol pulls the steering wheel towards "breasts", and IGF-1 slams the gas pedal. In fact, IGF-1 is the strongest determinant of breast size as measured during the follicular phase of cisgender women.
Risks of increasing IGF-1
Acromegaly, a masculinizing pronouncement of facial bone structure, is caused by abnormally high levels of IGF-1.
IGF-1 has been linked to breast cancer.
Naturally increasing IGF-1
Artificially increasing IGF-1
- Mk-677 amplifies the production of IGF-1, rather than simply increasing production by a constant level. This means that the body's natural cycle of IGF-1 production will only be heightened, with higher peaks. This drug has been under clinical investigation for some time, however its primary use is bodybuilders.
- This Reddit thread by justsallygirl is a national treasure.
- This other Reddit thread by a user who tried to test this.
- This list of ways to increase IGF-1.
- Breast Nexus is a natural breast enhancement forum. There's even a section for "genetic males."
- This BN thread discusses taking deer velvet extract under the tongue to get IGF-1 for possible breast enhancement.
- This other BN thread discusses a natural-ish BE regimen.