GLP-1 Patch: Clarification on Available Formulations
There is currently no FDA-approved GLP-1 receptor agonist available as a transdermal patch. All approved GLP-1 medications, including semaglutide (Ozempic, Wegovy) and dulaglutide (Trulicity), are administered either as subcutaneous injections or oral tablets 1, 2.
Available GLP-1 Formulations
Injectable Formulations (Subcutaneous)
Once-Weekly Injections:
- Semaglutide (Ozempic/Wegovy): 0.25mg to 2.4mg weekly, with absolute bioavailability of 89% and steady-state achieved after 4-5 weeks 1, 3
- Dulaglutide (Trulicity): Once-weekly injection for type 2 diabetes and cardiovascular risk reduction 2, 4
- Exenatide extended-release: Weekly administration 4
Daily Injections:
Oral Formulation
Oral semaglutide (Rybelsus): The only FDA-approved oral GLP-1 receptor agonist, taken daily, with clinical effectiveness approaching the once-weekly subcutaneous preparation 5, 4
Why No Patch Exists
GLP-1 receptor agonists are peptide-based medications that face significant challenges for transdermal delivery:
- Molecular size: These are large peptide molecules that cannot effectively penetrate the skin barrier 1
- Enzymatic degradation: GLP-1 is rapidly degraded by DPP-4 enzyme, requiring special formulation strategies like albumin binding (used in semaglutide) to extend half-life 1, 3
- Bioavailability requirements: Even oral semaglutide requires special absorption enhancers to achieve adequate bioavailability 5, 4
Current Administration Recommendations
For patients requiring GLP-1 therapy, the American Diabetes Association recommends:
- Subcutaneous injections remain the gold standard, with once-weekly formulations (semaglutide 2.4mg, dulaglutide) preferred for convenience and superior efficacy 6
- Injection sites: Abdomen, thigh, or upper arm achieve similar exposure with no clinically meaningful differences 1
- Oral semaglutide: Consider only when patients strongly prefer to avoid injections and glycemic control (not maximal weight loss) is the primary goal 5
Common Pitfall
Do not confuse GLP-1 receptor agonists with other diabetes medications that may have alternative delivery systems. If a patient is asking about a "patch," clarify whether they are seeking to avoid injections entirely (consider oral semaglutide) or are misinformed about available formulations 5, 4.