Did you mean collagen production, rather than glycogen production?
In any case, no problems here. I posted this in the "what are you taking" thread, but my offseason for the last 2-3 years has been test, primo, GH. Right now it's
1200 Test E
1000 Primo E
10iu GH / day
3 x 5-10iu Novolin-R on high carb days
No AI all year outside of the 6-8 weeks before a show. e2 was at 63 in bloods a few weeks ago, which seems to be just right - and I'm guessing that's part of the reason I don't have any connective tissue issues. From what I've read from other people, these doses might tank somebody else's estrogen, but I am probably a higher aromatizer. Last offseason was 1050 / 1050 each with similar results and feeling.
When funds were lower, I ran similar or slightly lower total doses with Test, EQ, and 300-400 Mast. I definitely like Test+Primo better...kind of intangible, but I feel better. I wouldn't necessarily say results are better with Primo vs. EQ in terms of tissue built, but I think its low side effects and synergy with high Test (acts as a very mild AI) make it a better choice.
The kidney toxicity issues may be overplayed with EQ, but I'd rather not take the risk if I can afford not to. For what it's worth, my eGFR and creatinine are right in range, as well. I think eGFR was fine on EQ, but creatinine was creeping up there...which, granted, could be for plenty of other reasons. I admit I don't take the few days off training pre-draw like most recommend.