I used Walmart’s Reli-on R and NPH right up until last year because I didn’t have insurance. It works just fine, but you have to understand that it’s a very different mechanism of action. It supposedly starts working in fifteen minutes, but I never noticed that. It was more like two hours. You really need to plan on eating before the two hour mark. It’s peak action works for another two hours or so, and then it starts winding down. It can linger a long time, though, but just at a very little amount of action. With R, you’re back to planning ahead of time how many carbs you’re going to eat. If you’re already eating, it’s too late.
I actually did pretty well on the R/NPH combo, though. It’s great if you’re a grazer and like to nibble often instead of sitting down for big meals.
If you intend to put it into your pump, though, you’re going to have to make some tweaks. I take slightly less humalog than R per carb ratio. You’ll have to figure out what works for you, but I would plan on extending your duration of action (or whatever your pump manufacturer calls it) by at least two hours, and also reduce your basal slightly to account for that lingering action tail. Essentially, the extra bolus insulin you’ll probably need is then subtracted from the basal rate, and it balances out in the end. There will probably be a tiny amount of the previous meals bolus still left in you as you go into lunch and dinner. Personally, I would set my nighttime basal back to normal about six hours after dinner, though, since that’s the longest fast most people go through in a day and eventually that dinnertime R will wear off before you wake.
Of course, you’re going to have to test a whole heck of a lot to figure out what works for you. Good luck!
Edited to add here that I forgot about R’s “eat now or die” nature. It takes a while to warm up, but it hits hard and fast when it does. Make sure you’re always ready to eat when the insulin bomb starts ticking.