The 29-year-old, who has long been a fans' favourite at Kingsholm and was voted Gloucester's Player of the Year in 2010, was due to remain in the West Country until the end of the season but will now head to France with immediate effect after a compensation package was agreed to cover the remainder of his contract.
"We are naturally disappointed to lose Q (Qera) at this time. However, on his return from the Autumn internationals, he requested for his own reasons to be released from his contract early," said Gloucester boss Nigel Davies, who has seen the likes of Billy Twelvetrees and Henry Trinder sign new deals but could lose star fly-half Freddie Burns to Leicester Tigers.
"On a personal level, it has been a pleasure working with Akapusi and I wish him well in his new career at Toulouse.
"As we continue to reshape the squad, we have a clear direction of where we want to be going forward. I am very pleased with the recruitment and retention of players we've already achieved and there will be more positive news in the New Year as we continue this process."
Qera has played more than 100 times for Gloucester in all competitions since joining from Birmingham-based Pertemps Bees after the 2007 Rugby World Cup, with 27 of those outings coming in continental competition. He has featured twice in Europe this season, coming off the bench in the win over Perpignan and starting the defeat at Munster, to take his Heineken Cup tally to 17.
Those two Pool 6 appearances for Gloucester in October mean he will be ineligible to play any further part in this year's competition with Toulouse, however, as Guy Noves and co look to push on towards a fifth Heineken Cup crown.
"For personal reasons, I feel the time is right for me to move on from Gloucester Rugby now after the last seven seasons at Kingsholm," added Qera.
"I would like to thank the Club and its supporters for the backing they have given me over the years, and my time at Gloucester will always be close to my heart.
"It's clear Gloucester Rugby is right to return to strengthening its core rugby values, and I am grateful to the Club for the understanding that it has shown me in my wish to pursue this opportunity with Toulouse."
Gloucester currently sit third in Pool 6 after two wins and two defeats from their opening four games but a bonus-point victory at home to Munster could yet see them top the table after Round 5.
They haven't reached the last eight in the Heineken Cup since 2007, a season when, ironically, it was Munster who ended their European dream at the quarter-final stage at Kingsholm.