What are hormones?
	What are the effects of cross-sex hormone therapy?
	What are potential side effects of hormone treatment in transsexuals?
	How can the intended effects of hormone therapy be maximized and the dangers minimized?

Hormones are the chemical messengers of the body, manufactured and controlled by the endocrine system. There are many different hormones with many different functions in the body, from water retention to controlling blood-glucose levels to instigating secondary sexual characteristics such as breast and beard growth.

The hormones that are of particular concern for transsexual people are estrogen, progesterone, and testosterone. Proportionally, biologic females have more estrogen and progesterone than males; biologic males have more testosterone.

The following effects have been observed in varying degrees with extended cross-sex hormone treatment. With effective and continuous dosages, most of these changes will start with the very first administration of hormones and will be mostly completed within 2-5 years. Genetic factors limit tissue response to hormone therapy, so individual results will vary.

A physician must carefully monitor hormone dosage --increasing dosage beyond a certain point will not increase the effects and could result in illness.

FTMs taking testosterone can realistically expect the following effects:

• a permanent deepening of the voice, though not necessarily all the way down to an average male frequency
• decreased fertility--menstrual cycles becomes irregular and eventually stop
• permanent clitoral enlargement
• mild breast atrophy (but not substantial reduction in size)
• increased upper body strength with exercise
• male-pattern facial and body hair growth
• male-pattern baldness
• increased sexual interest and arousal
• redistribution of fat from hip toward waist

Some of these changes are reversible if hormones therapy is ended. Others, such as facial hair and voice deepening, are not.

MTFs taking estrogen therapy can realistically expect the following effects:

• breast growth
• some redistribution of body fat to approximate a female body shape
• decreased upper body strength
• softening of skin
• decrease in body hair
• slowing or stopping the loss of scalp hair
• decreased fertility and testicular size
• less frequent, less firm erections

Some of these changes are reversible if hormones therapy is ended. Others, such as breast growth, are not.

Side effects in FTMs treated with testosterone may include:

• infertility
• acne
• increased emotional sensitivity and/or instability
• increases in sexual desire
• shift of lipid profiles to male patterns which increase cholesterol and the risk of cardiovascular disease
• the potential to develop benign and malignant liver tumors and liver dysfunction

Side effects in MTFs treated with estrogens may include:

• increased propensity to blood clotting (venous thrombosis with a risk of fatal pulmonary embolism)
• development of benign pituitary tumors
• infertility
• weight gain
• increased emotional sensitivity and/or instability
• liver disease

Some patients may not be able to tolerate cross-sex hormones. Patients with existing medical problems may be more likely to experience serious or fatal consequences of cross-sex hormonal treatments. For example, cigarette smoking, obesity, advanced age, heart disease, high blood pressure, blood clotting abnormalities, cancer, and some endocrine (hormonal) abnormalities increase the health risks for the use of hormonal treatment. A patient and his or her physician must decide together whether the risks of hormone therapy are worth the benefit.

> Examinations

• Check for existing medical problems before starting hormone treatment. People with existing medical problems may be more likely to experience serious or fatal consequences of cross-sex hormonal treatments. Before starting hormone therapy, get a complete physical examination. Your doctor may perform laboratory tests for liver function, electrolytes, lipids (cholesterol), prolactin, blood sugar, and estrogen and androgen levels. It may also be useful to monitor your skeletal health by measuring bone density, especially if you are more than 40 years old.
  
  
• Have liver function checks regularly and keep alcohol intake low. Testosterone and estrogens can, in rare cases, interfere with liver function and stimulate various kinds of liver tumors and cysts, especially if alcohol, drug use, or infection already weakens the liver. Reduce alcohol and other drug intake. Repeat liver function tests as recommended by your physician.

> Hormone dosage

• Start gradually. Do not start taking the maximum planned dosage of hormones at once. Your health care provider will use guidelines to determine an appropriate low starting dose. Watch for possible side effects and give the body time to adjust. If there are no problems after 1-2 months, you and your health care provider may increase the dosage to the planned level.
  
  
• Use appropriate dosages. Use the lowest hormone dose that gives the desired changes. Not everyone needs the same dose, because of differences in body weight and genetically determined sensitivity to hormones. A physician must carefully monitor hormone dosage. Increasing dosage beyond a certain point will not increase desirable effects and could result in illness.
  
  High doses of hormones for an extended period of time increase the risk of health consequences. It is usually not advisable to take pre-operative dosages of female or male hormones indefinitely. If you are able to have surgery to remove your hormone-producing organs (ovaries or testicles) you will be able to reduce the dosage of hormones you take to a safer level. In general, the lower the hormone dosage you can use for lifetime maintenance, the better.