I have been using Symlin since September, and I am a Type 1 on pump therapy.
How is it working for me? Very, very well. I have lost weight (about 30lbs), had my best A1c last month in over 10 years, and feel much more in control of my blood glucose levels.
Symlin mimics the action of a hormone produced by the islet cells called amylin. It works in a number of ways, but all completely within the central nervous system. The first thing you will notice upon beginning Symlin therapy is the dissolution of much of your appetite. It is safe to say I eat about half of what I used to eat at any given meal. I just get full on less food and pretty much anything on my plate 15 minutes or so after the Symlin injection is not getting eaten.
The very next thing you will notice is that your digestion is slowed. You will feel full much longer than you otherwise would after your meal. I rarely snack between meals now. This also means your post-prandial blood glucose levels will be much improved as there is no spike with Symlin, rather a gradual increase that is managed much easier than the spike. Total nutrient absorption is not affected by Symlin. Being on a pump is helpful here, as many Symlin users switch to square or dual wave boluses to cover the different (more natural) post-meal blood glucose patterns.
Symlin also signals your liver to stop dumping sugars into your bloodstream, which is part of how it eliminates the post-meal spike. This interesting effect can be useful after very strenuous exercise, which can also cause your liver to dump its glycogen into your blood (however, going by the label Symlin is only to be used with food containing 25 grams of carbs or more).
Finally, Symlin is able to reduce the amount of insulin you need to cover a meal by 30-50%. In my case it is actually more than that, as I use about 65-70% less insulin for meal boluses. My basal rates however, remain the same.
There is some discomfort associated with ramping up to your therapeutic dose, which for Type 1 diabetics is 60mcg. I recommend going for 120mcg, which is the maximum dose for Type 2 diabetics, because the positive effects are much more pronounced at that level. The discomfort includes nausea and some minor gastrointestinal issues, but you increase the dose by 15mcg every few days as your body quickly adjusts to the new medication and the side effects subside. So once the side effects stop at 15mcg, you move up to 30mcg and stay there until the side effects go away again. I noticed less discomfort as I went up the range- it was easier to go from 90mcg to 105mcg than it was to go from 15mcg to 30mcg.
Presently, at 120mcg I have no side effects.
The pH of Symlin is quite low and it can often feel as if you are injecting lemon juice. Insulin it is not! Unfortunately, this side effect does not go away.
All things considered, I strongly recommend all Type 1 diabetics use Symlin. After all, it is an important hormone produced by the same cells that produce insulin.