Breast development extension adrenocorticotropic hormone (ACTH)), and thyroid hormones such as thyroxine (and by extension thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH)) also play permissive but less well-understood/poorly-characterized roles in breast development during both puberty and pregnancy, and are required for full functional development. Leptin has also been found to be an important factor in mammary gland development, and has been found to promote mammary epithelial cell proliferation. In contrast to the female-associated sex hormones, estrogen and progesterone, the male-associated sex hormones, the androgens, such as testosterone and dihydrotestosterone (DHT), powerfully suppress the action of estrogen in the breasts. At least one
Transgender hormone therapy (male-to-female) the gender they identify with. Introducing exogenous hormones into the body impacts it at every level and many patients report changes in energy levels, mood, appetite, etc. The goal of the therapy, and indeed all somatic treatments, is to provide patients with a more satisfying body that is more congruent with their gender identity. Some medical conditions may be a reason to withhold hormone replacement therapy because of the harm it could cause to the patient. Such interfering factors are described in medicine as contraindications. Absolute contraindications – those that can cause life-threatening complications, and in which hormone replacement therapy