Umbrella labs , based on testing a lot of materials.Nope, use what you have been and just stay consistent with it.
The mirror changes are important. Being at a stalled weight is fine if you are seeing positive changes.
Make sure you are hitting your protien goal. This is important when losing weight.
How is your gym performance? Same? Declining?
I would up cardio and WO intensity and raise cals a bit if you can. Try for a week or two.
Hopefully from an approved source?