Caitlyn Jenner’s transformation included facial feminization surgery (FFS), a series of procedures that alter the face to increase its femininity.

According to Yahoo.com, experts say FFS requires a series of psychological ramifications and physical changes — including surgery — and change a person’s appearance to match how he or she has always felt to be inside.

Experts note cosmetic changes — in clothes, makeup, wigs — only go so far. FFS surgery can last four to 10 hours to make physical changes in the facial structure of patients, and can take up to three weeks of recovery.

““Facial feminization surgery is not superficial,” says Jeffrey Spiegel, MD, director of Advanced Facial Aesthetics in Massachusetts, who specializes in FFS. “It’s all about bone shape and the interplay of light and shadow.”

Psychologist Ben Michaelis, who has worked with transgender clients, tells Yahoo.com most people undergo profound psychological changes, including navigating relationships with family and friends.

“The data assert that over 95 percent of people who choose to live as a different gender than that which they have been identified at birth by others do not regret it,” he says. “If anything, it is a period of elation.”