I was on Ortho Novum 1/35 for many years, taken continuously for 3 months at a time. I think it stabilized things, but I wasn’t in as good or closely monitored control then, so hard to say. I’d be shocked if oral route impacted its ability to stabilize blood sugars, since it’s not the hormones you’re taking each day that does that so much, but rather the fact that taking those hormones regularly suppresses your body’s production of much higher amounts of naturally and variably occurring hormones. I otherwise tolerated the pill well, but eventually went off it because I wanted to see how it was affecting me, especially since I noticed appetite reduction in my off week. I did lose about 12 lbs when I did that, but my skin got worse and my periods eventually came back with a vengeance and with effects on my appetite and blood sugars.
I wanted to go back to an oral contraceptive again, for blood sugars and because my periods are pretty awful, but my doctor refused given my age (35 at the time), the fact that I have diabetes, and the risk for blood clots. They talked me into a Mirena, which I had for the better part of a year. Not sure how that impacted my blood sugars, but it was terrible—while insertion was actually not a big deal, the first six months involved a lot of cramping and spotting. and it made my chronic joint problems worse and made me depressed (which was not a problem with my combo pill or off of hormonal bc). Turns out the oft-repeated selling point that it’s only a small amount of hormones locally administered, so less likely to cause side effects is not backed up by research, and increasingly, findings suggest the type of progestin used in hormonal IUDs like Mirena have the highest risk of psychological symptoms and that Mirena has a bad side effect risk profile. Some women do fine with it, but a good amount do not. So while not diabetes-specific, I thought I’d mention it, since my diabetes was part of why I got pushed into getting one with false assurances about the lack of side effects. I got it removed and within a couple of months felt back to normal.
So yeah, I’ve given up on using contraceptives to manage my cycle in any way, at least for now.