Not related to hair, but Fenugreek is WELL KNOWN to increase breast size, and really helps "bring in milk" for breastfeeding mothers. I can attest that it works for both. I have taken it in oral capsule form (gelatin cap filled with fenugreek powder) the last 2-3 years. It increased my breast size by 1 cup but I have not always measured...and for a while I was taking maca root too. I began taking both for the health benefits, and because I consume a lot of protein, and fenugreek is excellent for stomach indigestion...which I sometimes get after a heavy protein meal. I figured I'd take both for health, and if it boosts the girls, cool!
About 3 months before I had my son, I made sure to take extra fenugreek (3 caps instead of 2 per day), and immediately after birth I had a really good supply of milk. Fenugreek is in those "Mother's Milk" tea blends that moms drink to encourage letdown and to increase milk supply. Im a good size up top for my body size, but I always wanted a bit more without surgery...fenugreek and maca root help.