Glad you've seen positive results, My 5 year old(nearly) boy had it in October and it took a good 8 weeks to see a difference but what a difference in him now, no chasing after dogs miles in the distance, no obsessive sniffing for ever every time he meets a dog, good quick response to being whistled or called and no aggression seen to other male dogs. He even looks for a treat now when we meet other dogs rather than finding them more interesting as this is what he's learnt.
I just wish I hadn't wasted money on the behaviourist when I knew in my gut it was all hormone related, which needed to be dampened down before I was going to get him to be more responsive to training.

Like you I will do another one but for 6 months and see what happens then. I did email virbac and ask if they get the surge again when a new implant is done but she said not and the 6 months is the minimum time it will last so I will see how he is in April before just doing it. His testicles have shrunk and not about showing him now but will give a couple ago this year and see how he gets placed, (he's already a champion so I know he is a nice specimen!) but I'd rather have an obedient and well mannered dog out on our walks than a show dog I can't let off the lead.

The time scale says a minimum is about 6 months, but it will be pend on individual dogs , my boys lasted for around 16 months before it wore off, you will get an idea by the size of his testicles, they will start to fill up and feel fuller, there is no normal timescale , just individual dogs, as a guide my boy weighs around 28 kg , his was done due to a health issue, it was either that or castration, but the plus side ( apart from his health ) was a much easier adolescent testosterone fuelled  git .

Well we are now about 18 weeks in and I very suddenly have a fat dog! Okay, not fat. But he has gone from being the bottom edge of very rangy but still healthy to the top edge of healthy and heading towards portly in literally about 4 weeks! I haven't weighed him but I would estimate 2.5kg! I am stunned as there has been no change to his diet and his exercise has steadily risen due to my training for this charity walk. It happened about 8 weeks from his testes stopping shrinking.

All is fine in the broad sense - he still has a waist and I have reduced his food to get a grip on it now, but just wanted to post to let people know that weight gain can be very late and very sudden! So keep an eye on your dogs even once past the point that you think you've seen the full effects.

In all other senses this has been very successful. We have a sprightly and interested poodle who is still a bit silly about other dogs but not dangerously ridiculous. G is nature is lovely, he's more playful than before (manly edge gone, back to boyish playfulness) and I think even a bit more patient (he was already very understanding of my autistic son but this endless patience now extends to the other kids too).

I should also add that the usual poodle anti gravity effect remains in full swing