This might be late for a reply so posting in case of any new users of Symlin. I've been using Symlin for about a year and 7 months. After the initial test of 15McG, the results were immediate and after starting a regular regimen of 60 McG three times a day, my insulin intake dropped over 60% (along with diet changes of VERY low carb). Over the same period of time, I dropped almost 80 pounds which was put on due to insulin resistance and wasn't aware of that until a new endocrinologist figured it out and suggested Symlin. I have and continue to have great success with Symlin including maintaining my size 6. I have had to increase it to 120McG and I do still get slightly nauseated for a couple minutes but it passes quickly. My quick acting insulin (Humalog) dropped from around 30 units a day to about 10 or less and my long-acting (Levemir)from 40 to 25. The only drawback is of course the injections so over the long holiday I am going to be testing Victoza which is supposed to be once a day.
You do not need to take Symlin at the same time as your insulin. For example, I can take Humalog in the morning (about 2 units at around 0615) then go to work and take only the Symlin at about 0830 or 0900. As long as there is some insulin still available in the body the Symlin works perfectly. It does not do anything without the insulin though. Depending on where or what I am doing, I may wait to take it because the effects help my blood sugars stay consistent. My blood sugars average about 110 and I almost never go over 180.
I've been type one over 40 years and would be considered "1.5" with the resistance. Without the Symlin, I would still be miserable trying to fight the weight with no success. Not sure of usage over a very long period of time although for myself I did have to increase the dosage. If trying it out, highly suggest testing at home for a couple days and be very aware of the amount of insulin your are taking. The Symlin may work too well causing some hypoglycemia and may be a little tough to correct until the Symlin is in the down curve of action. I great trick I found was to use honey sticks (like the flavored straws). Just chew the end off the straw and let the honey coat the inside of your bottom lip for fast absorption. It tastes great and is good for you.