One side growing faster than the other is quite normal and usually resolves itself but many women end up still having a bit of asymmetry in their breasts. Compression to the breasts, such as using a chest binder or sleeping on them, can damage them and stunt their growth, so be careful not to sleep on one if you sleep on your side, and avoid sleeping on your stomach. Nighttime is when the breasts grow most and compression will prevent them from that.
Gently massaging the smaller breast will improve circulation to assist growth and increase IGF-1 levels[1] which will stimulate the breast to grow bigger.[8][9]
If your areola and nipple still remain small and flat, you can apply a single drop of progesterone cream carefully around the edges of the areola, but not on it, just before bed. It will diffuse into the areola and help it grow bigger by stimulating progesterone receptors (PR) in the nipple that stimulate the epidermal growth factor receptors responsible for areolae growth. Be careful not to apply it directly to the nipple, overapply it, or apply it for more than a few weeks or your nipple growth may outpace the growth of your breasts and look really strange! (I've seen it happen before to someone misusing progesterone cream. In general, to raise progesterone levels it should only be applied below the waist to be absorbed into the bloodstream evenly and safely since our circulation system is not symmetrical.)
If you can't get progesterone cream you can use skin cream that stimulates the estrogen receptors, such as pueraria mirifica, shatavari cream or fennel oil in a sunflower carrier oil (a nice estrogenic, anti-androgenic combo.) Their estrogenic activity will weakly stimulate PR and help your areolae and nipple grow although not as much as real progesterone.
If that doesn't help, unfortunately there's not much you can do. Phytoprogestogens such as apigenin and kaempferol in chaste tree extract are about 1/10th as strong as progesterone and compete against it, reducing PR activity over 50% in presence of real progesterone.[2] Naringenin, found in grapefruit and tomatoes, enhances PR activity but only slightly.[10]
The ethanol extract of xu duan (Japanese teasel root/dipsacus asperoides) has been shown to be potent at activating PR.[3] I have not seen it available as a tincture though. It's not to be confused with wild teasel/dipsacus sylvestris tinctures. Xu duan is commonly sold raw from traditional Chinese medicine shops online and could be made into a tincture. The herb is used (6-21g) in TCM formulations for fertility and sustaining pregnancy, much like progesterone. There's not much data yet on its efficacy or safety for affecting PR in the human body, but I plan to experiment with it a bit in a few weeks. If a pregnant mother can take it, I don't think it'll hurt. I'll make a thread documenting my experience when I do.
Alternatively, you can try to raise your progesterone levels to help them grow and hope they even themselves out. Taking moderate doses of fenugreek (3g/60kg/day),[4] melatonin,[5] vitamin C[6], vitamin E and L-arginine[7] may increase progesterone levels, although supplementation studies on progesterone in genetic males are hard to find to confirm.
Reference
- Insulin and Insulin-Like Growth Factor I (IGF-1) Increase in preterm Infants following massage therapy.
- Phytosteroids Beyond Estrogens: Regulators of Reproductive and Endocrine Function in Natural Products.
- Molecular screening of Chinese medicinal plants for progestogenic and anti-progestogenic activity.
- My post on fenugreek.
- Melatonin: shedding light on infertility?-a review of the recent literature.
- Effects of ascorbic acid supplementation on serum progesterone levels in patients with a luteal phase defect.
- Luteal blood flow and luteal function.
- Hormonal Breast Augmentation: Prognostic Relevance of Insulin-Like Growth Factor-I.
- Growth hormone treatment induces mammary gland hyperplasia in aging primates.
- Biological characterization of non-steroidal progestins from botanicals used for women’s health.
