Usually Not. Most cases of gynecomastia are not treated with hormonal therapy. If persistent, it is often best treated with partial excision of the prominent glandular tissue as well as liposuction surgery of the peripheral chest area. If the prominence of the chest wall is caused by adipose tissue, then liposuction surgery may suffice.
Generally not. While some cases of male breast enlargement are due to hormone imbalances, in the vast majority the cause is unknown. The treatment is generally surgical with a combination of liposuction and direct removal of glandular tissue. This operation is usually quite successful and leaves very small scars. Rarely, skin will have to be removed; this will result in more scarring.
Not usually/legally. Although many hormone therapies such as those used for prostate cancer and other medications may produce gynecomastia, it is generally not treated or prevented with oral medications due to concerns with adverse side effects. However, it has come to my attention that body builders illicitly using andrgneic hormones will take tamoxifen to prevent side effects of breast growth.