The Magpies academy graduate confirmed his departure from his boyhood last month after spending the last decade working his way through the youth setup.
Allan become a regular part of the United Under-23s side in recent years and was handed a first senior call-up for an FA Cup Third Round tie at Rochdale in January 2020.
The former Cramlington Juniors forward remained on the bench for the 1-1 draw at the Crown Oil Arena but was handed his senior bow by Steve Bruce in a St James Park replay ten days later.
Allan replaced Magpies captain Jamaal Lascelles just before the hour-mark and made an impact by setting up Joelinton for the final goal of a 4-1 win against the League Two club.
The youngster would make no further senior appearances for United but would find first-team action during loan spells with Accrington Stanley and Scottish Championship club Greenock Morton.
He was named alongside the likes of Mo Sangare and Adam Wilson on United’s list of released players but has now joined National League neighbours Gateshead after former Magpies star Mike Williamson saw off competition from a number of other clubs to secure his signature.
Allan will join a Heed side primed for attacking play after they scored over a century of goals in all competitions last season - and the former Magpies academy star is looking forward to enhancing that style of play during the new campaign.
He said: “The experience in the men’s game definitely helped but now it’s time to kick on and this is the perfect opportunity.
“I’ve done the loan things and stuff, I’ve been away from home, that wasn’t really a problem for me.
“There were conversations with other clubs that weren’t in the North East but once I had spoken to the manager and the style they want to play, it suits me so it was the perfect fit.
“I am very attacking, I’ve got a lot of pace, like getting in behind the defence and scoring goals so hopefully that is what will happen this season.
“The style of football is the main reason I have ended up here. The stats speak for themselves, the amount of goals the forwards scored last season is exciting so hopefully I can replicate that and get as many numbers as they did.”
Allan is the latest former United academy graduate to join Gateshead with Adam Campbell, Owen Bailey, Greg Olley, Louis Storey and Dan Ward all plying their trade at the International Stadium.