Born in the Eastern Cape, Saphetha joined the Congress of South African Students while at school and rose to become its provincial chair.

[1] In 1990, Saphetha was elected as the African National Congress's (ANC) political commissar for Pankie Dobo, and he served on the party's regional executive for Port Elizabeth.

He joined the National Education, Health and Allied Workers' Union (NEHAWU), becoming a shop steward and then branch chair.

In 2008, he was elected as NEHAWU's regional chair for KwaZulu-Natal, and before the end of the year was also its acting provincial secretary.

[2] In 2019, he was additionally elected as general secretary of the Trade Union International of Public Services and Allied Employees.