The Main Point of Cytomel . . .
. . . is fat burning and conversion, not weight loss.
Halo makes a good point - By taking cytomel (of which Cynomel is a brand name) along with sten, you're not going to lose weight. If anything, the sten will tend to make you gain weight, as will any test.
Any time you take AS or related substances - whether test (including sten), sytomel, clen, etc. - what you are doing is essentially reversing your ratio of body fat to lean muscle mass. Think of it as a see-saw: one side goes up while the other goes down, but the total weight on the see-saw doesn't change. Even so, your body will show an overall improvement.
When I started doing test, for example, I started watching what I ate a bit more carefully - I didn't want to gain pounds. And, combining the AS with more intense workouts, I noticed that my weight stayed the same but my fat decreased/lean muscle mass increased. (Without watching diet or increasing my workout, the sten alone would make you gain pounds, not lose them.)
In other words, if you want to lose weight, don't focus on anything with a heavy anabolic component (like sten). And don't bother with anything that will zonk you into la-la land (like insulin or lasix). Just do ephedrine or an ECA stack, watch what you eat, and increase your cardio to burn more calories. More effective and safer.