GLP-1 receptor agonists are medications used to manage type 2 diabetes and support weight management, traditionally given by injection. Whilst transdermal patch delivery systems are being explored in research, it is crucial to understand that no GLP-1 patches are currently licensed or approved for use in the UK. Any such patches exist only within formal clinical trials. This article examines the current evidence on investigational GLP-1 patches, including potential wearing durations, application methods, and safety considerations, whilst highlighting the licensed injectable alternatives available through the NHS.

What Are GLP-1 Patches and How Do They Work?

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of medications primarily used to manage type 2 diabetes and, in some formulations, to support weight management. Traditionally administered via subcutaneous injection, some research has explored transdermal patch delivery systems as an alternative route of administration.

It is important to note that no GLP-1 transdermal patches are currently licensed or approved for use in the UK. Any GLP-1 patches would only be available within formal clinical trials, and patients should not attempt to obtain such products online or through unofficial channels.

GLP-1 is an incretin hormone naturally produced in the gut that plays a crucial role in glucose homeostasis. When administered therapeutically, GLP-1 receptor agonists work through several mechanisms:

• Enhancing insulin secretion from pancreatic beta cells in a glucose-dependent manner

• Suppressing glucagon release from alpha cells, reducing hepatic glucose output

• Slowing gastric emptying, which helps moderate post-meal blood glucose rises

• Promoting satiety through central nervous system pathways, potentially supporting weight reduction

Investigational transdermal GLP-1 delivery systems typically utilise specialised technologies such as microneedles or active delivery methods rather than conventional patches, as GLP-1 molecules are large peptides that do not easily penetrate the skin barrier. These experimental systems aim to deliver the medication into systemic circulation without traditional injections.

Currently in the UK, injectable GLP-1 receptor agonists such as semaglutide (Ozempic) and dulaglutide (Trulicity) are well-established treatments recommended by NICE (NG28) for specific indications in type 2 diabetes management, with some formulations also approved for weight management.

How Long Do You Wear a GLP-1 Patch?

As no GLP-1 transdermal patches are currently licensed for use in the UK, there are no approved products with established wearing durations. Any information about wearing periods for GLP-1 patches relates to investigational products that may be in development or testing phases.

In clinical trials investigating transdermal GLP-1 delivery systems, researchers have explored various wearing durations, including daily and weekly applications. However, the optimal wearing time would be determined by the specific product design, drug formulation, and delivery technology, and would be clearly specified in any future product's Patient Information Leaflet (PIL) if approved.

For patients currently using licensed injectable GLP-1 receptor agonists in the UK:

• Once-daily formulations include liraglutide (Victoza)

• Once-weekly formulations include semaglutide (Ozempic), dulaglutide (Trulicity), and exenatide extended-release (Bydureon)

If you are participating in a clinical trial involving a GLP-1 patch, you must strictly follow the specific instructions provided by the research team regarding application duration, replacement schedule, and all other aspects of use. Never deviate from the trial protocol without consulting the research team.

For patients with type 2 diabetes or obesity who are interested in GLP-1 therapies, discuss the currently licensed options with your GP, practice nurse, or diabetes specialist nurse. These healthcare professionals can provide guidance on the most appropriate treatment approaches based on NICE guidelines and your individual clinical needs.

When and How to Apply Your GLP-1 Patch

Since no GLP-1 transdermal patches are currently licensed in the UK, the following information is general guidance that would apply to investigational products only. If you are participating in a clinical trial involving a GLP-1 patch, you must follow the specific instructions provided by the research team.

General principles for transdermal patch application include:

• Choose an appropriate site: Common application areas for transdermal medications typically include the abdomen, upper arm, or thigh. The specific approved sites would be detailed in the product information.

• Rotate application sites: Do not apply consecutive patches to exactly the same location. Rotating sites reduces the risk of skin irritation. Allow sufficient time before reusing the same site, as directed in the product guidance.

• Prepare the skin: Wash the area with mild soap and water, then dry thoroughly. Avoid using lotions, oils, moisturisers, or alcohol-based products on the application site, as these may interfere with patch adhesion or drug absorption.

• Apply correctly: Follow the specific application technique described in the product instructions. Generally, this involves removing the protective backing and pressing the patch firmly onto the skin for the recommended time period.

• Timing: Apply at consistent times as directed to maintain steady drug levels.

Important safety considerations for transdermal patches:

• Avoid applying external heat (such as heating pads, hot water bottles, electric blankets, or prolonged sun exposure) to the patch area, as this may increase drug absorption and side effects

• Do not cut patches or apply additional adhesives unless specifically instructed to do so

• Wash hands thoroughly after handling patches to avoid transferring medication to eyes or mucous membranes

For patients currently using licensed injectable GLP-1 receptor agonists, continue to follow the administration instructions provided in the PIL and by your healthcare team.

What to Do If Your Patch Falls Off Early

As no GLP-1 transdermal patches are currently licensed in the UK, the following represents general guidance only. If you are participating in a clinical trial involving an investigational GLP-1 patch, you must contact your research team immediately for specific instructions if your patch becomes detached.

For any transdermal medication patch, the appropriate action if detachment occurs would be detailed in the specific product's Patient Information Leaflet (PIL). General principles that might apply include:

If a patch becomes detached:

• Follow the specific instructions in the product information or trial protocol

• In many cases, the recommendation would be to apply a new patch and adjust the schedule as directed

• Do not reapply a detached patch unless specifically instructed that this is safe for your particular medication

• Do not apply multiple patches to compensate for a detached patch unless explicitly directed by a healthcare professional

To prevent patch detachment:

• Ensure the skin is completely clean and dry before application

• Avoid areas where clothing might rub against the patch

• Consider activity levels when choosing an application site

• Only use additional adhesives or overlay dressings if specifically approved for use with your particular patch

For safe disposal:

• Follow the specific disposal instructions provided with the product

• Generally, used patches should be folded with the adhesive sides together

• Keep used patches out of reach of children and pets

• Return to a pharmacy for safe disposal if you are unsure about proper disposal methods

If you experience recurrent patch detachment during a clinical trial, inform your research team promptly. For patients using licensed injectable GLP-1 receptor agonists who have concerns about their treatment, contact your GP or diabetes care team for advice.

Side Effects and Safety Considerations

GLP-1 receptor agonists, regardless of delivery method, share a common side effect profile related to their mechanism of action. The most frequently reported adverse effects are gastrointestinal in nature and typically occur during treatment initiation or dose escalation. These include:

• Nausea and vomiting (very common, affecting more than 1 in 10 patients)

• Diarrhoea or constipation

• Abdominal discomfort or bloating

• Reduced appetite

These symptoms often diminish over several weeks as the body adjusts to the medication. Eating smaller, more frequent meals and avoiding high-fat foods may help manage gastrointestinal side effects. If experiencing severe gastrointestinal symptoms, maintain adequate hydration to prevent dehydration and potential acute kidney injury.

Transdermal delivery systems may additionally cause local skin reactions, including redness, itching, or irritation at the application site. Rotating sites with each application reduces this risk. If you develop severe skin reactions, blistering, or signs of allergic contact dermatitis, remove the patch and seek medical advice promptly.

Serious but rare adverse effects associated with GLP-1 receptor agonists include:

• Pancreatitis: If suspected, the medication should be discontinued immediately. Seek urgent medical attention if you experience severe, persistent abdominal pain radiating to the back, particularly if accompanied by vomiting

• Hypoglycaemia: Whilst GLP-1 agonists alone rarely cause low blood glucose, the risk increases when used alongside insulin or sulfonylureas. Ensure you recognise hypoglycaemia symptoms (tremor, sweating, confusion, palpitations)

• Gallbladder problems: Report symptoms such as right upper abdominal pain, fever, or jaundice

• Diabetic retinopathy complications: Patients with pre-existing retinopathy should have regular eye examinations

Important safety warnings:

• Pregnancy and breastfeeding: GLP-1 receptor agonists are not recommended during pregnancy or breastfeeding. For semaglutide specifically, treatment should be discontinued at least 2 months before a planned pregnancy. Use effective contraception while taking these medications.

• Insulin adjustment: The MHRA has warned about the risk of diabetic ketoacidosis (DKA) when insulin is reduced or stopped when starting a GLP-1 receptor agonist. Any insulin dose adjustments should only be made under clinical supervision.

The MHRA advises reporting any suspected adverse reactions via the Yellow Card Scheme (yellowcard.mhra.gov.uk). Contact your GP or diabetes team if you experience persistent side effects, have concerns about your treatment, or if your blood glucose control deteriorates whilst using GLP-1 therapy.

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