But unlike most transgender people in Asia, who are left to self-administer hormone supplements, Chalit is being helped by a pioneering clinic.
"I am in the hands of doctors," said Chalit, who was born female but identifies as a man.
"I'm not doing it by myself, so it isn't dangerous," the software company worker said.
Several days after receiving his first testosterone injection, Chalit returned to get a blood test at Tangerine, the new clinic inside a Red Cross center in downtown Bangkok.
The center is a pilot program that organizers hope could be replicated across Asia.
Its location is no accident-Thailand has a large and visible transgender population and is one of the world's top destinations for sex-reassignment surgery.
But just like elsewhere in Asia-Pacific, a region home to more than 9 million transgender people, according UN estimates, long-term care for patients is patchy at best.
The clinic is a rare place providing follow-up treatment, both physical and mental, for those who have undergone sex-reassignment surgeries, procedures where patients are often at risk of infection.
"Most of the centers where the surgery is performed only provide short-term post-surgical care," explained Nittaya Phanuphak, the head doctor at Tangerine.
In Thailand, hormones are commonly purchased on the Internet or in local pharmacies, and administered on advice gleaned from friends or Web forums.