The medical issues involved in gender transition are complex and require the involvement of medical specialists to ensure the safety of the process.
Male to female procedures
Male to female gender transition usually involves cross-gender hormone therapy, including the use of anti-androgens to block testosterone (the male sex hormone produced by the human body). Female sex hormones including estrogen and sometimes progesterone (female sex hormones) are then used to feminise the body.
Physical effects of male to female hormone therapy include a reduction in body hair, growth of breasts, loss of muscle mass, and redistribution of soft tissue around the body to produce a more feminine shape. Erections will cease nearly immediately, and male genitals will slowly shrink in size over a number of years. Emotions intensify significantly, and people tend to laugh, cry, and pick up social cues far better than was previously the case. Male sex drive is gradually replaced by a very different female sexuality. Sexual orientation may change, but this varies between individuals and does not always occur.
Loss of body hair is almost instant but is reversible if hormone therapy is discontinued, as are the emotional changes and tissue redistribution if they turn out to be unwanted. Breast growth is slow and may take as many as five to seven years to complete. However growth of nipples may occur fairly quickly in some people and these changes require surgery to reverse if a person decides not to complete transition.
Risks of hormone therapy include thrombosis and blood clots, breast cancer, and an increase in depression or other pre-existing psychiatric illnesses. For this reason it is important that hormone therapy be supervised by either an endocrinologist or a general practitioner with significant experience in administering hormone replacement therapy. Involvement of a psychiatrist or clinical psychologist with gender experience is recommended in all cases given the extreme social stresses that often accompany a gender transition.
Facial hair will usually be unaffected by cross gender hormone therapy. People with pale skin and slow growing, fine, dark facial hair may sometimes succeed in eliminating facial hair using laser treatment. More commonly, the only way to eliminate this hair is through electrolysis, a procedure in which a needle is inserted into each follicle one by one, and the follicle is destroyed through a combination of heat and chemical reaction. The process is very expensive, painful and time consuming, and can involve several hours per week of treatment over several years. It can be avoided entirely if male puberty is blocked in childhood before the facial hair has started growing.
Surgery is required in many cases to feminise the bone structure of the face and also to shave the larynx and remove the "adams apple" which is a distinctive male characteristic. Again, these procedures are unnecessary if the male puberty is blocked in childhood.
Breast implants may be used if the breast growth from hormone therapy is unsufficient, which is usually the case if the person's mother has small breasts or if transition is commenced late in life where the body's response to cross-gender hormone therapy is reduced.
It is almost always possible to train the male larynx to produce an acceptable female voice, however this requires significant effort and sometimes involves a lot of practice. In other cases, people going through male to female transition pick up the techniques fairly effortlessly. Voice surgery is available but can be dangerous and is only used in exceptional cases.
To create female genitals, surgery is required including orchidectomy (castration) and penectomy (removal of the majority of corpus spongiosum and ereticle tissue from the inside of the penis). Modern surgical techniques usually retain the most sensitive part of the glans penis along with its blood supply and this is repositioned to become a clitoris. The penile skin and scrotal skin are the used to fashion inner and outer labia, and to line the vaginal canal.
Results vary depending on the success of the surgery and the exact technique used but a good outcome is sensate, orgasmic, and allow for sexual intercourse. Most successful results will appear similar to a natal vagina without close observation, but will be distinguishable to someone who is a medical expert or who has had significant sexual experience with both natal and transsexual women.
A surgically created vagina is usually not self lubricating, and following most surgical techniques regular dilation will be necessary throughout life in order to retain vaginal depth. It is not unusual for patients to require one or two revision procedures to get a perfect result, and where possible funds should be allocated for this purpose in advance.
Male to female genital surgery is completely irreversible, and a person considering such surgery should make absolutely sure that she wishes to live as a woman for the rest of her life before consenting to it. Issues that need to be considered it the withdrawal of family support, loneliness, lifelong infertility, and the small but real risk of a loss of sexual sensation in the genitals in case of necrosis in the area. Risks of complications are considerably increased for smokers, and for patients who are significantly overweight or ignore directives by surgeons to cease cross-gender hormone therapy for 2-4 weeks prior to surgery.
Surgeons will usually require letters of approval from two psychiatrists (in Australia or the USA), or from a clinical psychologist or psychiatrist in Thailand. Usually 12 months living in the desired gender and taking cross-gender hormone therapy is required prior to surgery, although some of the Thai surgeons may be open to a shorter real life test in exceptional circumstances.
An alternative to full genital surgery is orchidectomy (castration), which due to the toxicity and side effects of anti androgens is advisable for anyone who wishes to maintain cross-gender hormone therapy over a lifetime without having surgery. There are several surgeons in Australia who are willing to do this procedure with psychiatric approval, and the cost is usually under $1000 after medicare rebate.
Female to male procedures
Female to male hormone therapy typically involves the use of testosterone to masculinise the body. It
produces significant and irreversible effects rather quickly, although some of the effects such as facial hair growth may take a number of years.
Immediate effects of female to male hormone therapy include a significant increase in energy levels and sex drive which becomes more characteristically "male". Menstruation will cease almost immediately.
Permanent changes to the larynx to produce a deeper, typically male voice, and an increase in muscle mass and redistribution of soft tissue to produce a more characteristically male shape. Body hair and facial hair growth will increase, although this change will take more time. Over time, male hormones may cause male pattern baldness, and increase the risk of heart disease as they do in natal men.
Female breasts will remain unless removed via mastectomy, and a radical hysterectomy is used to remove the uterus and ovaries.
Results of female to male genital surgery and far less satisfactory than the male to female counterpart, and people undertaking that surgery are forced to choose between two types of procedures.
The clitoris enlarges naturally under female to male hormone therapy and a metiodplasty can refashion it into a sensate penis that is capable of erection when the person is aroused. However, the resulting penis is far smaller than would usually be the case for a natal man.
A phalloplasty is a complex multi-stage procedure that will produce a full-sized penis out of tissue taken either from the forearm or abdomen. However, the resulting penis cannot usually become erect on its own, and is not fully sensate. The risks of complications and outright failure for phalloplasty are far greater than for metiodplasty or equivalent male to female surgeries.
Genital surgery is irreversible, and requires the approval of a clinical psychologist or psychiatrist. Some surgeons may require letters from two psychiatrists. Such approval is usually obtained after a 12 month "real life test" living full time as a male and taking cross gender hormone therapy.
