It has incredible success for weight loss, and is one of the very few FDA-approved peptides
But the doses required (typically 5001,500 mg of berberine per day) are far beyond what a small patch can plausibly deliver through the skin, even before you account for the absorption barrier
Food and Drug Administration (FDA) in 2021 for chronic weight management in adults and children 12 and older with obesity and for adults who are overweight with one or more weight-related health conditions, like type 2 diabetes or high blood pressure
Clin Immunol (2013) 149(3):55665
However, injection site reactions such as redness or irritation may also occur
A 3D-printed hydrogel patch coated with VEGF and modified by tetrapodal zinc oxide particles has been developed to achieve controlled release of VEGF and regulate angiogenesis during wound healing (Siebert et al., 2021)