His father was a merchant in Curaçao who later became rabbi of Congregation Shearith Israel in New York City following the death of Gershom Mendes Seixas.
He spent several years practicing medicine in the West Indies after graduating, returning to New York in 1823.
He worked as a physician for the New York City Dispensary, and from 1826 to 1827 he lectured on "abdominal diseases and complain[t]s of females."
[3] In 1836, Peixotto was elected an Honorary Member of the Medical Society of Lower Canada and appointed Professor of Theory and Practice of Medicine and Obstetrics.
He was a close friend of Andrew Jackson, supporting his election to the presidency and editing the True American on his behalf.
[3] In 1813, his father Moses Levy Maduro Peixotto had been one of the six founding members of the Supreme Council, Scottish Rite, Northern Jurisdiction.