While transdermal patches are indeed an effective delivery system for some medications (think nicotine patches or birth control patches), this method only works for drugs with very specific characteristics
If you are on tirzepatide at 5 mg or 7.5 mg and feeling like it is not working, the answer is almost certainly dose optimization rather than adding a second medication
Bmc Gastroenterol 17(74)
Retatrutide is still investigational, has not been approved by the FDA, and its full safety profile has not yet been established, meaning it does not affect weight loss in any confirmed, clinically approved way, unlike GLP-1 drugs
SMAD3 adaptor proteins Adaptor proteins in the TGF- pathway, such as II-Spectrin, Smad anchor for receptor activation (SARA), and Disabled-2 (Dab2), play critical roles in facilitating SMAD protein activation and regulation (Mishra and Marshall 2006