Doctors will continue to monitor her condition and provide treatment, the statement said.
Known in Thailand as “Princess Bha”, the 46-year-old is the eldest daughter of King Maha Vajiralongkorn and the only child from his first marriage.
Educated in Britain, the United States and Thailand, Bajrakitiyabha has held a number of positions with the United Nations and has campaigned for better treatment of women in prisons.
She is seen as close to her father, and was appointed to a senior role in his bodyguard command a year before her hospitalisation.
The 73-year-old king, who has seven children from four marriages, has not announced his chosen heir, though succession rules favour men.
Strict rules govern what can and cannot be said about the Thai royal family, who are protected from criticism by lese-majeste laws that carry prison sentences of up to 15 years per charge.
– Agence France-Presse