Wegovy (semaglutide 2.4 mg) is licensed in the UK exclusively for once-weekly subcutaneous injection, not every two weeks. The Medicines and Healthcare products Regulatory Agency (MHRA) has approved this specific dosing regimen based on clinical trial data demonstrating efficacy and safety with weekly administration. Extending the interval to fortnightly dosing represents off-label use without supporting evidence, potentially compromising therapeutic outcomes. This article examines why weekly dosing is essential, the risks of altering the schedule, and what to do if you miss a dose.
Quick Answer: No, Wegovy must be taken once weekly as licensed by the MHRA; taking it every two weeks is off-label use without supporting clinical evidence and may reduce efficacy.
Wegovy (semaglutide 2.4 mg) is licensed in the UK exclusively for once-weekly subcutaneous injection, not every two weeks. The Medicines and Healthcare products Regulatory Agency (MHRA) has approved this specific dosing regimen based on extensive clinical trial data demonstrating both efficacy and safety when administered weekly. The medication comes in pre-filled, single-dose pens designed for self-administration on the same day each week, providing consistent therapeutic levels throughout the treatment period.
The standard dosing schedule begins with a gradual escalation protocol to minimise gastrointestinal side effects. Patients typically start with 0.25 mg weekly for four weeks, then increase to 0.5 mg, 1 mg, 1.7 mg, and finally the maintenance dose of 2.4 mg weekly. Each dose level is maintained for at least four weeks before escalation. If the 2.4 mg dose is not tolerated, it may be reduced to 1.7 mg; if 1.7 mg is not tolerated, treatment should be discontinued as per the UK SmPC.
NICE guidance (TA875) recommends Wegovy for weight management in adults with a body mass index (BMI) of at least 35 kg/m² (or at least 30 kg/m² with weight-related comorbidities). For people of South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean family backgrounds, the BMI thresholds are reduced by 2.5 kg/m². Treatment must be prescribed within specialist weight management services and is typically limited to two years. Wegovy should be used alongside a reduced-calorie diet and increased physical activity.
Wegovy must not be used during pregnancy or breastfeeding, and women of childbearing potential should use effective contraception. Treatment should be discontinued at least two months before a planned pregnancy.
Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist with a half-life of approximately seven days, specifically engineered for once-weekly administration. The molecular structure includes modifications that allow it to bind reversibly to albumin and resist degradation by the enzyme dipeptidyl peptidase-4 (DPP-4), as detailed in the European Medicines Agency's European Public Assessment Report (EPAR) for Wegovy.
Weekly injections maintain steady-state plasma concentrations that optimise the medication's multiple mechanisms of action. Semaglutide works by enhancing glucose-dependent insulin secretion, suppressing inappropriately elevated glucagon secretion, slowing gastric emptying, and—crucially for weight management—reducing appetite through central nervous system pathways. These effects require consistent GLP-1 receptor stimulation to produce the therapeutic benefits observed in clinical trials, including the STEP (Semaglutide Treatment Effect in People with obesity) programme.
Extending the dosing interval to two weeks would likely result in reduced drug exposure during the latter part of the interval. As semaglutide concentrations decline, the degree of GLP-1 receptor activation may diminish, potentially allowing appetite to return and reducing the medication's weight management efficacy. Steady-state concentrations are typically achieved after 4-5 weeks of weekly dosing at the same dose level.
Clinical trial data supporting Wegovy's approval were generated using weekly administration. There is no evidence base for efficacy or safety with fortnightly dosing, meaning patients using this altered schedule would be taking the medication outside its licensed indication and without supporting clinical data. The STEP 1 trial, published in the New England Journal of Medicine (2021), demonstrated efficacy with weekly dosing, not alternative schedules.
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Start HereTaking Wegovy every two weeks instead of weekly represents off-label use that is not supported by clinical evidence or regulatory approval. The primary concern is reduced therapeutic efficacy—the medication may not work as intended for weight management. The STEP clinical trials demonstrated mean weight loss of approximately 15% in people without diabetes (STEP 1) and 10% in people with type 2 diabetes (STEP 2) over 68 weeks using weekly dosing. There is no evidence linking fortnightly dosing to equivalent weight loss outcomes.
Using Wegovy outside its licensed schedule complicates clinical oversight. Healthcare professionals cannot accurately assess treatment response or attribute side effects when the medication is not being used as prescribed. This is particularly important for monitoring adverse effects such as nausea, vomiting, diarrhoea, constipation, and abdominal pain—the most commonly reported side effects of Wegovy.
Patients should be aware of red flag symptoms requiring urgent medical attention. These include severe, persistent abdominal pain (which may radiate to the back) with or without vomiting, which could indicate pancreatitis, or symptoms of gallbladder problems such as pain in the upper right abdomen, fever, or yellowing of the skin or eyes. If these occur, contact NHS 111 or 999 as appropriate.
NHS funding and prescription issues may also arise. NHS prescriptions under NICE TA875 are based on licensed indications and dosing schedules. Using Wegovy every two weeks may be considered off-label use, potentially affecting NHS funding eligibility. For private prescriptions, patients should be aware that off-label use may have implications for clinical responsibility. Patients should never alter their prescribed dosing schedule without explicit guidance from their prescribing clinician.
If you miss your scheduled weekly Wegovy injection, the UK SmPC provides clear guidance based on how much time has elapsed. If you remember within five days (120 hours) of your missed dose, administer the injection as soon as possible, then resume your regular weekly schedule. For example, if your usual injection day is Monday and you remember on Thursday, take the dose immediately and continue with the following Monday as planned.
However, if more than five days have passed since your missed dose, skip that injection entirely and resume your normal schedule with the next planned dose. The SmPC specifies that you must maintain at least 72 hours (three days) between doses. Do not take two doses within three days of each other to "catch up", as this increases the risk of gastrointestinal side effects and other adverse reactions.
If you miss two or more consecutive doses during the dose escalation period, you may need to restart the titration schedule or consider a lower maintenance dose. Consult your healthcare provider for specific guidance in this situation.
If you frequently miss doses or find the weekly schedule difficult to maintain, contact your GP or prescribing clinician rather than attempting to modify the schedule yourself. They can discuss strategies to improve adherence, such as setting phone reminders, linking injections to a regular weekly activity, or using calendar alerts. Some patients find it helpful to prepare their injection supplies the evening before their scheduled dose day.
Persistent difficulty adhering to the weekly schedule may indicate that Wegovy is not the most suitable treatment option for you. Your healthcare provider can discuss alternative weight management strategies, including other medications with different dosing schedules, or non-pharmacological approaches. Never extend your dosing interval to every two weeks without explicit medical advice—this constitutes off-label use without supporting evidence and may compromise both safety and effectiveness.
Taking Wegovy every two weeks is off-label use without clinical evidence and may significantly reduce its weight management efficacy. Semaglutide's seven-day half-life requires weekly dosing to maintain steady therapeutic levels for appetite suppression and metabolic effects.
If you miss a Wegovy dose, take it within five days (120 hours) and resume your regular weekly schedule. If more than five days have passed, skip that dose entirely and continue with your next planned injection, maintaining at least 72 hours between doses.
Yes, NICE guidance (TA875) recommends Wegovy on the NHS for adults with BMI ≥35 kg/m² (or ≥30 kg/m² with weight-related comorbidities), prescribed within specialist weight management services alongside diet and exercise. Treatment is typically limited to two years.
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