The Reyeses named their sauce "Mang Tomas Sarsa", after a popular lechon shop located in La Loma, Manila.

In 1991, the brand was acquired by Southeast Asia Food, Inc. (SAFI, now NutriAsia).

Unlike the traditional lechon sauce, Mang Tomas is made without ground liver.

Liver was a listed ingredient in the internationally available Mang Tomas products until 2017 but has since been removed from the label.

[2] As of 2022, all Mang Tomas variations reinclude pork liver as an ingredient.