Rob Chakraverty is standing down from his role as England senior men's team doctor.
With the English Football Association for the last four years, he has recently faced scrutiny relating to allegations from his previous post as UK Athletics' chief medical officer between 2013 and 2016.
Dr Chakraverty is now leaving his role with Gareth Southgate's Three Lions and moving on to pastures new.
An FA spokesperson said: "The FA can confirm Dr Rob Chakraverty is to stand down from his role with the England senior men's team.
"We would like to offer our sincere thanks to Rob, not just for his part in the team's progress since 2016 but also in sharing his expertise across the wider medical department. We wish him every success for the future.
"A decision regarding his replacement will be made ahead of the next England camp, whenever scheduled."
Dr Chakraverty said it had been a privilege to work in the role since 2016 - a period that included England's run to the World Cup semi-finals in Russia.
"The team and players have been wonderful to work with and the memories of what we achieved together at the World Cup two years ago will stay with me forever," he said.
"The time is now right to step away from this role and seek new challenges enabling my successor to establish themselves into the team before the next tournament.
"I would like to thank my colleagues and the players for their support and wish them every success in achieving their goals in the tournaments to come."
Chakraverty was the doctor who administered L-Carnitine to Mo Farah in 2014, but all within permitted levels.
L-carnitine is a naturally occurring amino acid which some studies suggest could boost athletic performance if it is injected directly into the bloodstream.
A BBC Panorama documentary aired last month revealed that Farah repeatedly denied receiving an injection of the controversial supplement ahead of the 2014 London Marathon when questioned by investigators the following year, before later changing his account.
Farah was tested six days after that race and the BBC reported that, despite listing a number of other products and medicines, he failed to record L-carnitine on his doping control form.
The documentary revealed that Farah, who won the 5,000 metres and 10,000m gold medals at the 2012 and 2016 Olympic Games, was interviewed by investigators from the US Anti-Doping Agency (USADA) in 2015 as part of its probe into his former coach Alberto Salazar and asked whether he had been given L-carnitine before the previous year's London Marathon.
Farah denied having been given the injection in the initial 2015 interview with USADA. Panorama reported he then met with UK Athletics' head of distance running Barry Fudge immediately after the interview and returned to the interview room as the investigators were preparing to leave in order to correct himself.
L-carnitine is not a prohibited substance under WADA rules. Injections and infusions of it were permitted within WADA rules in 2014 provided the volume was below 50 millilitres every six hours. The permitted volume is now 100ml every 12 hours.
Chakraverty told the Digital, Culture, Media and Sport Committee in 2017 "an injection" of L-carnitine had been a joint decision between him and Fudge, taken after research, considering the risks and possible side-effects.
The committee was assured the volume was 13.5ml, well within the allowable limit, though Dr Charaverty failed to record that in his notes. There is no evidence any rules were broken.
In a statement to the BBC Dr Chakraverty said: "I have not contravened any [world anti-doping] rules, and have always acted in the best interests of those I treat.
"The evidence I provided to [MPs] was an honest account - including an acknowledgement that my usual standard of record keeping slipped due to heavy work commitments and travel. The GMC reviewed this and concluded that the case required no further action."