Spiritually, it is believed that tshachu, drubchu and smenchu owe their origin to the good wishes and blessings of Buddhas and Boddhisattavas.
According to this textbook, tshachu contain a combination of rdo-sol (coal), mu-zi (sulphur) and rdo-sho (limestone).
Another belief is that Zhapdrung Ngakwang Namgyel (1594–1651) arrived in Gasa, he visited the hot springs which relieved his fatigue and joint pain.
Dendup Norzang is the local deity of Gasa Tsachu; originally a "wrathful demon" he later became a "peaceful dharma protector.
Water-Based Therapies of Bhutan: Current Practices and the Recorded Clinical Evidence of Balneotherapy, Water Journal, 2021, Volume 13, Issue 9.