Yea, I've done helios + L-carnatine. It works if you're at a caloric deficit. It won't burn the fat by itself, but if you're already dieting it allows you to target the fat loss. Start with a very low dose. I started with the recommended dosage I found online and I had constant tremors all day.. its very uncomfortable.
But it did work for lower abs and fat pad. Don't inject into the exact same spot each time, but move it all around the fat pad.
I don't know exactly how much was exposed, probably 1/8th inch, but it was the first time I got veins popping out down there