So, I've been using Symilin alongside my low-carb way of eating for over a month now and I think I have seen some significant improvements in my glucose control. It's taken a bit of experimentation to figure out what works best, but I had some good info to work from as a starting point.
I take my Symilin dose between 0-10 minutes before sitting down to eat. Once or twice I took it 20 minutes before eating and after a few bites the "satiety effect" kicked in and I didn't feel like eating as much as I had planned (another reason to bolus after the meal).When I take it close to a meal, I have about 15-20 minutes of serious scarfing before I feel full. Sometimes I don't even notice the satiety effect, but I just eat what I normally do and I'm done.
It is helpful to eat roughly the same amount of protein and carbohydrate in my meals. I'm not even sure exactly how it measures, but I know what it looks like. For most meals I eat 4-6 oz. of protein and some green veggies or salad. If I eat a meal that is slightly different than this, I just use the same amount and plan to correct if needed. When I'm off, the surplus is usually corrected by an evening walk or a small correction 4 hours post meal. A few times I have used a larger bolus for a meal that seemed larger I have ended up getting lows post-meal. When I have had a more active day or am running lowish all day, I will bolus even less.
Insulin Dose Consistency/ Timing
For this average amount of food, I take 1.8 units of Novolog and spread it out over 60-90 minutes with a square bolus. I change the timing post-meal depending on what my starting BG was. If I start a meal over 100 mg/dl I will take it a bit sooner, sometimes even right after a meal. But, if I start a meal at 70-80 mg/dl I give the food plenty of time to start to bring my glucose up and then take the bolus. This would normally be about an hour post-meal.
Taking Symilin After a Meal
A handful of times I have eaten a meal without taking Symilin (because it wasn't with me at the moment) and I have taken it post meal. I didn't notice any difference. I think the low-carb meals are already slow to impact glucose, so there seems to be some wiggle room there.
I have read about people having lows that are hard to correct when using Symilin. The reason they are uniquely tricky is that when your digestion is slowed down, it can be hard to get glucose to be quickly absorbed when correcting a low. This knowledge made me very cautious about my insulin dosages while using Symilin. During the first 2-3 weeks using it I was running my BGs higher than usual out of caution. Over time, I have found that my modest doses of insulin do not cause extreme drops, with or without Symilin. The lows I have had in the 50-60 mg/dl range have been easily corrected with 1-2 glucose tablets. The sugar was absorbed normally, and I saw improvement quickly. I think that a low-carb way of eating helps to avoid some of the risks of difficult hypos because the boluses are kept small.
The results have been good for me. I have had rather flat post-meal numbers and I have been able to reduce my total daily insulin. I'm using about 10-20% less insulin.