Recent university graduate Benyapon Chimsud, who was born a man but identifies as female, said she has been taking hormones for two years.

"I have been taking hormones by myself for two years. I consult with my friends" to determine the proper doses of contraceptive pills, she explains.

She also gets monthly black market estrogen injections at a rudimentary neighborhood clinic.

That leaves her cut off from regulated healthcare, prone to receiving inaccurate medical advice and at risk of over-consuming hormones in a rush to see rapid results.

Chalit, on the other hand, met with a psychiatrist several times before receiving his first injection to prepare for the changes to his body.

"The psychiatrist asked me how long I've wanted to be a man, and whether my friends and other people around me would accept it if I changed," Chalit told AFP.

Now he is getting hormone injections every two weeks.

"The hormones will stop my periods, change my voice, give me a beard and mustache, and develop my muscles," he said. "All the things that will help me no longer be a woman."

That should insulate him from the dangers of taking the wrong doses of hormones, which experts say can lead to liver and cardiovascular problems.

HIV is also a risk if needles are shared.

Rights groups like the Asia-Pacific Transgender Network say this public health issue is largely neglected by the mainstream medical community.