LOSE WEIGHT WITH MEDICAL SUPPORT — BUILT FOR MEN
- Your personalised programme is built around medical care, not willpower.
- No generic diets. No guesswork.
- Just science-backed results and expert support.
Find out if you’re eligible
Ozempic (semaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for treating type 2 diabetes mellitus in adults. The lowest dosage of Ozempic available is 0.25 mg, administered once weekly via subcutaneous injection. This starting dose is designed to help your body adjust to the medication whilst minimising gastrointestinal side effects. Understanding the lowest dose, when it might be increased, and what to expect during initiation is essential for safe and effective diabetes management. This article explains the dosing schedule, side effects, and who should begin treatment at the lowest Ozempic dosage, in line with MHRA and NICE guidance.
Quick Answer: The lowest dosage of Ozempic available in the UK is 0.25 mg administered once weekly via subcutaneous injection, serving as a four-week initiation dose before escalation.
Ozempic (semaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus in adults. The lowest available dosage of Ozempic is 0.25 mg administered once weekly via subcutaneous injection. This initial dose is specifically designed as a starting dose to allow the body to adjust to the medication and minimise the risk of gastrointestinal side effects.
It is important to understand that the 0.25 mg dose is not intended as a maintenance dose for long-term diabetes management. According to the Summary of Product Characteristics (SmPC) approved by the Medicines and Healthcare products Regulatory Agency (MHRA), this lowest dose serves as an initiation phase lasting four weeks. During this period, patients and healthcare professionals can monitor tolerability and assess any adverse reactions before dose escalation.
Ozempic is supplied in pre-filled, multi-dose pens that deliver specific dosages. The pens are designed to deliver either 0.25 mg and 0.5 mg doses (in the same pen), or separate pens for the 1 mg and 2 mg doses, as specified in the SmPC. The 0.25 mg/0.5 mg pen allows for the initial titration schedule. After the four-week initiation period at 0.25 mg, the standard protocol involves increasing to 0.5 mg once weekly, which represents the first maintenance dose for many patients.
The rationale behind starting at the lowest dose relates to semaglutide's mechanism of action. As a GLP-1 receptor agonist, it slows gastric emptying and affects gastrointestinal motility. Gradual dose escalation allows the digestive system to adapt, significantly reducing the incidence and severity of nausea, vomiting, and other gastrointestinal symptoms that are common when GLP-1 agonists are initiated at higher doses. This approach is recommended in the MHRA-approved SmPC to optimise tolerability whilst working towards achieving glycaemic control.
LOSE WEIGHT WITH MEDICAL SUPPORT — BUILT FOR MEN
Find out if you’re eligible
Dose escalation of Ozempic follows a structured titration schedule based on both glycaemic control requirements and individual tolerability. After the initial four-week period at 0.25 mg, your doctor will typically increase the dose to 0.5 mg once weekly. This first maintenance dose is often sufficient for many patients to achieve their HbA1c targets.
If additional glycaemic control is needed after at least four weeks at 0.5 mg, your clinician may increase the dose to 1 mg once weekly. This decision is based on your most recent HbA1c results, fasting glucose readings, and overall diabetes management goals. NICE guideline NG28 recommends individualised HbA1c targets, typically aiming for 48 mmol/mol (6.5%) for most adults with type 2 diabetes who are not at significant risk of hypoglycaemia, or 53 mmol/mol (7.0%) for those taking medications that can cause hypoglycaemia. These targets may be adjusted based on individual circumstances, including frailty, comorbidities, and hypoglycaemia risk.
For patients requiring further intensification, a maximum dose of 2 mg once weekly is available. However, this highest dose should only be considered after spending at least four weeks at the 1 mg dose and demonstrating inadequate glycaemic response. Your doctor will carefully weigh the potential benefits of improved glucose control against the increased risk of side effects at higher doses.
Factors influencing dose escalation decisions include:
Your current HbA1c level and distance from your individualised target
Tolerability of the current dose (particularly gastrointestinal symptoms)
Presence of cardiovascular disease (semaglutide has demonstrated cardiovascular benefits in the SUSTAIN-6 trial, as noted in the SmPC)
Concurrent diabetes medications and risk of hypoglycaemia
Renal function (no dose adjustment is required for renal impairment, including severe impairment, though caution is advised due to potential dehydration risk)
Your healthcare team will schedule regular reviews, typically every 3–6 months, to assess whether dose adjustment is appropriate. It is essential never to adjust your Ozempic dose independently—always consult your GP or diabetes specialist nurse before making any changes to your treatment regimen.
Whilst the lowest dosage of Ozempic (0.25 mg) is specifically designed to minimise adverse effects, gastrointestinal symptoms remain the most commonly reported side effects even at this initiation dose. Understanding what to expect can help you manage these effects and distinguish between normal adjustment reactions and symptoms requiring medical attention.
The most frequent side effects at lower Ozempic doses include:
Nausea (very common, affecting ≥1/10 patients according to the SmPC)
Diarrhoea (common, affecting ≥1/100 to <1/10 patients)
Constipation (common)
Abdominal discomfort or pain (common)
Reduced appetite (common)
Dyspepsia (indigestion) (common)
These gastrointestinal effects typically occur during the first few weeks of treatment and often diminish as your body adjusts to the medication. The lower starting dose significantly reduces both the frequency and severity of these symptoms compared to initiating treatment at higher doses.
Other side effects that may occur at the 0.25 mg dose, though less commonly, include fatigue, dizziness, and injection site reactions such as redness, itching, or mild swelling. These local reactions are usually mild and transient.
Hypoglycaemia (low blood sugar) is uncommon with Ozempic monotherapy at any dose, as GLP-1 receptor agonists work in a glucose-dependent manner. However, if you are taking Ozempic alongside sulfonylureas (such as gliclazide) or insulin, your risk of hypoglycaemia increases, and your doctor may need to reduce the dose of these other medications.
When to seek medical advice:
Persistent vomiting preventing fluid intake (risk of dehydration and potential acute kidney injury)
Severe abdominal pain, particularly if radiating to the back (potential pancreatitis)
Symptoms of gallbladder problems (severe abdominal pain, fever, jaundice)
Signs of hypoglycaemia if taking other diabetes medications
Allergic reactions (rash, difficulty breathing, swelling)
Visual changes or symptoms of diabetic retinopathy worsening
If you experience troublesome side effects at the lowest dose, contact your GP or diabetes care team. They may recommend strategies to manage symptoms, such as eating smaller meals, avoiding high-fat foods, or temporarily maintaining the lower dose for longer before escalation.
If you are taking warfarin, your INR should be monitored when initiating Ozempic treatment.
Suspected side effects should be reported via the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk or the Yellow Card app).
All patients initiating Ozempic therapy should begin with the lowest 0.25 mg dose, regardless of their diabetes severity, body weight, or previous experience with other diabetes medications. This universal starting approach is recommended in the MHRA-approved SmPC and represents best practice for patient safety and tolerability.
The rationale for this standardised initiation applies across all patient groups because the gastrointestinal side effects of GLP-1 receptor agonists are dose-dependent and occur regardless of individual patient characteristics. Starting at 0.25 mg allows the body's GLP-1 receptors in the gastrointestinal tract to adapt gradually, significantly improving treatment adherence and reducing discontinuation rates.
Certain patient groups require particular attention during Ozempic initiation:
Elderly patients (aged 65 and over): No dose adjustment is required based on age alone, but older adults may be more susceptible to dehydration from gastrointestinal side effects. The lowest starting dose with careful monitoring is especially important in this population.
Patients with gastrointestinal conditions: Those with a history of gastroparesis, inflammatory bowel disease, or chronic gastrointestinal symptoms should be counselled extensively about potential side effects. The lowest dose initiation is crucial, and some patients may need to remain at 0.25 mg or 0.5 mg longer than the standard four-week period. Ozempic is not recommended in patients with severe gastrointestinal disease, including severe gastroparesis.
Individuals with renal impairment: According to the SmPC, Ozempic can be used without dose adjustment in patients with renal impairment, including severe impairment and end-stage renal disease. However, these patients require careful monitoring due to the increased risk of dehydration from gastrointestinal side effects, which could potentially worsen kidney function.
Patients with previous GLP-1 agonist intolerance: If you have previously discontinued a different GLP-1 receptor agonist due to side effects, your doctor may still consider Ozempic, as tolerability varies between agents. However, a cautious approach with extended time at the lowest dose and slower titration may be appropriate.
Those taking multiple diabetes medications: If you are currently taking sulfonylureas or insulin, your doctor will likely reduce the dose of these medications when starting Ozempic to minimise hypoglycaemia risk, but you will still begin Ozempic at 0.25 mg.
Patients with a history of pancreatitis should be monitored closely, and treatment should be discontinued if pancreatitis is suspected.
Pregnancy and breastfeeding: Ozempic should not be used during pregnancy or breastfeeding. Women of childbearing potential should use effective contraception when treated with semaglutide, and it should be discontinued at least 2 months before a planned pregnancy.
It is important to note that Ozempic is not licensed for type 1 diabetes or diabetic ketoacidosis. Additionally, whilst semaglutide is available in a higher-dose formulation (Wegovy) specifically for weight management, Ozempic is licensed solely for type 2 diabetes treatment in the UK, and prescribing decisions should align with NICE guidance and local formulary recommendations.
No, the 0.25 mg dose is an initiation dose designed for the first four weeks of treatment to allow your body to adjust. After this period, the dose is typically increased to 0.5 mg once weekly, which serves as the first maintenance dose for many patients.
The 0.25 mg dose is not intended for long-term maintenance. Your doctor will assess your HbA1c levels and diabetes control after four weeks and determine the appropriate maintenance dose, typically starting at 0.5 mg once weekly.
Yes, gastrointestinal side effects such as nausea and diarrhoea typically occur during the first few weeks and often diminish as your body adjusts. Starting at the lowest dose (0.25 mg) significantly reduces the frequency and severity of these symptoms compared to higher initial doses.
All medical content on this blog is created based on reputable, evidence-based sources and reviewed regularly for accuracy and relevance. While we strive to keep content up to date with the latest research and clinical guidelines, it is intended for general informational purposes only.
DisclaimerThis content is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional with any medical questions or concerns. Use of the information is at your own risk, and we are not responsible for any consequences resulting from its use.
