Can you take Victoza and Trulicity together? No, you should not combine these medications. Both Victoza (liraglutide) and Trulicity (dulaglutide) are GLP-1 receptor agonists used to manage type 2 diabetes. They work through identical mechanisms, making concurrent use unnecessary and potentially harmful. UK product information does not support their simultaneous use, and NICE guidelines do not recommend dual GLP-1 therapy. Combining them offers no additional glucose-lowering benefit whilst increasing the risk of gastrointestinal side effects, pancreatitis, and hypoglycaemia. If you are considering changes to your diabetes treatment, consult your GP or diabetes specialist nurse for safe, evidence-based alternatives.

Can You Take Victoza and Trulicity Together?

No, you should not take Victoza and Trulicity together. Both medications belong to the same class of diabetes medicines called GLP-1 receptor agonists (glucagon-like peptide-1 analogues), and concomitant use is not recommended in their UK product information. Using them together offers no expected additional benefit whilst potentially increasing the risk of adverse effects.

Victoza (liraglutide) and Trulicity (dulaglutide) work through identical mechanisms in the body, making concurrent use both unnecessary and potentially harmful. The UK Summaries of Product Characteristics (SmPCs) for both medications do not support their simultaneous use, and NICE guidelines do not recommend dual GLP-1 receptor agonist therapy.

Key reasons why these medications should not be combined include:

• Overlapping mechanisms of action with no expected additive glucose-lowering benefit

• Potential for increased gastrointestinal side effects such as nausea, vomiting, and diarrhoea

• Theoretical increased risk of pancreatitis, which is a known class warning

• Risk of hypoglycaemia, particularly if used alongside insulin or sulphonylureas

• Unnecessary medication costs and treatment burden

If you are currently prescribed one of these medications and are considering a change in your diabetes management, you should discuss this with your GP or diabetes specialist nurse. They can assess whether switching from one GLP-1 receptor agonist to another might be appropriate, or whether adding a different class of diabetes medication would better suit your treatment goals. Never start, stop, or change diabetes medications without professional medical guidance, as this can lead to dangerous fluctuations in blood glucose levels.

If you experience any suspected side effects from your medication, report them via the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

Why Combining Victoza and Trulicity Is Not Recommended

The primary reason for avoiding the combination of Victoza and Trulicity lies in their pharmacological redundancy. Both medications stimulate the same GLP-1 receptors in the pancreas, gastrointestinal tract, and brain, meaning that taking both simultaneously has not been studied and is not expected to enhance glucose control beyond what either medication achieves alone. This principle of avoiding therapeutic duplication is fundamental to safe prescribing practice.

Gastrointestinal adverse effects represent the most common concern when GLP-1 receptor agonists are used, even as monotherapy. These medications slow gastric emptying and affect gut motility, leading to nausea, vomiting, diarrhoea, constipation, and abdominal discomfort. Combining two GLP-1 agonists may amplify these effects, potentially causing significant gastrointestinal distress. Many patients already find it challenging to tolerate a single GLP-1 receptor agonist during the initial titration period.

Pancreatitis risk is another important consideration. Whilst the absolute risk remains low, GLP-1 receptor agonists have been associated with acute pancreatitis in post-marketing surveillance data. The UK product information advises healthcare professionals to counsel patients about recognising symptoms of pancreatitis. You should seek urgent medical help if you experience severe, persistent abdominal pain (which may radiate to the back), persistent vomiting, or signs of dehydration. Using two medications from this class simultaneously has not been studied but could theoretically increase this risk.

Severe gastrointestinal side effects can lead to dehydration, which may increase the risk of acute kidney injury. This is particularly important if you are also taking other medications that affect kidney function.

From a practical standpoint, combining these medications would also represent poor resource utilisation within the NHS, as there is no evidence of additional benefit from dual therapy, and it would not be considered cost-effective according to NICE principles.

How Victoza and Trulicity Work Similarly

Understanding the shared mechanism of action between Victoza and Trulicity helps explain why combining them is inappropriate. Both medications are synthetic analogues of human GLP-1, a naturally occurring incretin hormone released by the intestines in response to food intake. GLP-1 plays a crucial role in glucose homeostasis through multiple complementary pathways.

The primary mechanisms of action include:

• Glucose-dependent insulin secretion: Both medications enhance insulin release from pancreatic beta cells, but only when blood glucose levels are elevated. This glucose-dependent action reduces the risk of hypoglycaemia compared to medications like sulphonylureas

• Suppression of glucagon: They inhibit the release of glucagon from pancreatic alpha cells, reducing hepatic glucose production when it is not needed

• Delayed gastric emptying: Both slow the rate at which food leaves the stomach, leading to more gradual glucose absorption and increased satiety

• Central appetite regulation: GLP-1 receptors in the brain influence appetite and food intake, contributing to weight loss—a beneficial effect for many people with type 2 diabetes

The main difference between Victoza and Trulicity lies in their pharmacokinetic properties rather than their fundamental mechanism. Victoza (liraglutide) has a half-life of approximately 13 hours and requires once-daily subcutaneous injection. Trulicity (dulaglutide) has been engineered for a longer half-life of approximately 5 days, allowing for once-weekly administration. This difference in dosing frequency represents a convenience factor rather than a difference in how the medications work at the cellular level.

Both medications reduce HbA1c (a measure of average blood glucose over 2–3 months) and promote weight loss. Cardiovascular outcome benefits have been demonstrated in large clinical trials (LEADER for liraglutide and REWIND for dulaglutide). NICE guidelines recognise both as appropriate options within the GLP-1 receptor agonist class, with selection often based on patient preference regarding injection frequency, tolerability, and cost considerations.

What to Do If You're Considering Switching Between Them

Switching from Victoza to Trulicity, or vice versa, is a recognised clinical practice that may be appropriate in certain circumstances. However, this transition should always occur under medical supervision with careful planning to ensure continuity of glucose control and minimise adverse effects.

Common reasons for switching between GLP-1 receptor agonists include:

• Preference for less frequent injections (moving from daily Victoza to weekly Trulicity)

• Intolerable side effects with one medication that may be better tolerated with another

• Inadequate glucose control despite optimal dosing

• Cost or formulary considerations within your local NHS trust

• Availability issues or supply chain disruptions

Important: Do not overlap GLP-1 receptor agonists. When switching between these medications, you should stop one medication and start the other at the next scheduled dose. For example, if switching from Victoza to Trulicity, you would take your last dose of Victoza one day, then start Trulicity the following day or on your chosen weekly injection day. No washout period is generally needed, but there should be no overlap in treatment.

If you are switching from Victoza to Trulicity, your doctor will likely start you on the standard initial dose of Trulicity 0.75 mg once weekly, even if you were on a higher dose of Victoza. Dose escalation should then follow the recommendations in the Trulicity product information as tolerated and clinically indicated.

Important steps when switching:

• Continue monitoring your blood glucose levels more frequently during the transition period

• Be aware that gastrointestinal side effects may recur even if you tolerated the first medication well

• Keep a symptom diary to discuss with your diabetes team at follow-up

• Ensure you understand the new injection technique and schedule

• If you are also taking a sulphonylurea or insulin, your doctor may review these doses to minimise hypoglycaemia risk during transition

• Report any concerning symptoms, particularly severe abdominal pain, persistent vomiting, or signs of hypoglycaemia

Your GP or diabetes specialist nurse will typically arrange a follow-up appointment 8–12 weeks after switching to assess your HbA1c and determine whether the new medication is providing adequate glucose control. Never attempt to switch medications independently or use both medications during a transition period.

Alternative Diabetes Treatment Combinations

Whilst combining two GLP-1 receptor agonists is inappropriate, there are numerous evidence-based combination strategies for managing type 2 diabetes when a single medication does not achieve adequate glucose control. NICE guidelines provide a structured approach to intensifying diabetes treatment based on individual patient factors, including HbA1c targets, cardiovascular risk, renal function, and patient preferences.

Appropriate combinations with GLP-1 receptor agonists include:

Metformin plus a GLP-1 receptor agonist: This represents the most common and well-established combination. Metformin works primarily by reducing hepatic glucose production and improving insulin sensitivity, mechanisms that complement rather than duplicate the actions of GLP-1 agonists. This combination is often recommended as a second-line option when metformin alone does not achieve target HbA1c levels.

GLP-1 receptor agonist plus SGLT2 inhibitor: Sodium-glucose co-transporter-2 (SGLT2) inhibitors such as dapagliflozin, empagliflozin, or canagliflozin work by increasing urinary glucose excretion. This mechanism is entirely distinct from GLP-1 agonists. The combination of a GLP-1 receptor agonist with an SGLT2 inhibitor may be considered based on individual cardio-renal profile and in line with NICE guidance. Select agents with proven benefits for your specific situation.

GLP-1 receptor agonist plus basal insulin: For people requiring further treatment intensification, combining a GLP-1 agonist with long-acting insulin (such as insulin glargine or insulin degludec) can be effective. The GLP-1 component helps control post-meal glucose excursions and mitigates the weight gain typically associated with insulin therapy. Fixed-ratio combinations containing both a GLP-1 agonist and basal insulin in a single injection device are available in the UK (insulin degludec/liraglutide; insulin glargine/lixisenatide).

GLP-1 receptor agonist plus DPP-4 inhibitor: This combination is not recommended in NICE guidance. DPP-4 inhibitors (such as sitagliptin) prevent the breakdown of naturally occurring GLP-1, whilst GLP-1 agonists provide synthetic GLP-1. The combination offers minimal additional benefit and is not cost-effective.

Important considerations for combination therapy:

• Regular monitoring of HbA1c (typically every 3–6 months) to assess treatment effectiveness

• Increased vigilance for hypoglycaemia when combining with sulphonylureas or insulin

• Renal function monitoring, particularly with metformin and SGLT2 inhibitors

• Cardiovascular and renal benefits should influence medication selection in people with established complications

• Patient education about the different mechanisms and side effect profiles of each medication

Your diabetes care team will work with you to develop an individualised treatment plan that balances glucose control, minimisation of side effects, cardiovascular and renal protection, and quality of life. If you feel your current diabetes management is not adequately controlling your blood glucose levels, or if you are experiencing problematic side effects, contact your GP or diabetes specialist nurse to discuss alternative treatment options. Regular review and adjustment of diabetes medications is a normal part of managing this progressive condition effectively.

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