The 22-year-old will be with Boro initially until November 25th.
Lobjoit began his career in the youth set-up at MK Dons before being snapped up by Coventry City in November 2012.
He was described by then Sky Blues manager Mark Robbins as a "precocious talent" and put straight into their development squad.
He did not make the expected progress with Coventry, however, and was released in January 2014.
He turned out for Hemel Hempstead Town, New Bradwell St Peter, Leighton Town and Arlesey Town but it was with Buckingham Town that he came to the fore, scoring an amazing 62 goals in just thirty-six games for Buckingham and was the ChromaSport & Trophies United Counties League player of the year for 2016/17.
Lobjoit was given a trial by Queens Park Rangers but it was Northampton who gave him his second crack at the professional game and signed a two-year contract in July.
He scored against Corby Town in a pre-season friendly at Steel Park and was given the first-team squad number 12 for 2017/18.
He is highly regarded at Sixfields and joined Corby on a month's loan in September 2017, making an impressive debut in a 2-1 defeat at Chasetown.