Phenotyping of congenic dipeptidyl peptidase 4 (DP4) deficient Dark Agouti (DA) rats suggests involvement of DP4 in neuro-, endocrine, and immune functions
Experience data that makes sense while tracking progress of fat loss, calories burned, and activity levels over time
Pay attention to red flags like persistent vomiting, severe abdominal pain, signs of dehydration, and blood in the stool
Other (less serious) concerns are if EGF can properly penetrate the skin (as it is a medium-sized, polar molecule, so a special delivery system is probably needed), if it can affect collagen synthesis (or just works on the surface plumping up only the upmost layers of the skin) and if it has beneficial effects at all when used in isolation versus when used in a "conditioned media" that contains lots of growth factors resembling the synergistic balance found in the skin
Imaging plays an important role in both diagnosis and prognosis