What are Ozempic and liraglutide?
Ozempic and Saxenda are both injectable GLP-1 receptor agonist medications, but they contain different drugs and are licensed for different purposes.
Ozempic, made by Novo Nordisk, contains semaglutide. It’s approved in the UK for type 2 diabetes only and isn’t licensed for weight loss.
Semaglutide is also available at higher doses under the brand name Wegovy, which is licensed for weight management. This is a common source of confusion when comparing Ozempic to weight-loss medications.
Saxenda, also made by Novo Nordisk, contained liraglutide at a dose of 3 mg and was licensed in the UK for weight management.
However, Novo Nordisk has discontinued Saxenda to focus its manufacturing capacity on newer medications, like Wegovy.
A generic version of liraglutide, called Nevolat (manufactured by Zentiva), is now widely available in the UK as a direct replacement. It contains the same drug at the same doses, so there’s no clinical difference between the two.
How these medications work
When we eat, our gut releases hormones that regulate hunger and blood sugar. One of the most important is GLP-1 (glucagon-like peptide-1), which slows digestion, reduces appetite, and helps the pancreas release insulin.
Our body breaks down natural GLP-1 very quickly, within minutes of its release. Both Ozempic and liraglutide resist this breakdown, so their effects last much longer.
How liraglutide (Saxenda/Nevolat) works
Liraglutide mimics GLP-1 only. It slows gastric emptying, communicates with the brain’s appetite control centre to reduce hunger, and improves blood sugar levels.
Because liraglutide is cleared from the body relatively quickly compared with newer GLP-1 medications, it must be injected every day. It has a half-life of approximately 13 hours.
How semaglutide (Ozempic) works
Semaglutide also mimics GLP-1, but it was developed after liraglutide and was specifically engineered to have a longer duration of action.
It has a half-life of approximately one week, meaning a single injection provides sustained appetite and blood sugar control for seven days.
This longer-lasting action likely contributes to the greater weight loss seen with semaglutide in clinical trials.1
Clinical evidence
STEP 8: semaglutide vs liraglutide head-to-head
The STEP 8 trial published in JAMA is the only head-to-head comparison of semaglutide and liraglutide for weight loss. It included 338 adults with overweight or obesity (without diabetes) over 68 weeks.1
Key results:
- Semaglutide 2.4 mg: -15.8% body weight loss
- Liraglutide 3 mg: -6.4% body weight loss
- Treatment difference: -9.4 percentage points in favour of semaglutide
The proportion achieving clinically meaningful weight loss:
| Weight loss target |
Semaglutide 2.4 mg |
Liraglutide 3 mg |
| ≥5% body weight |
88%1 |
58%1 |
| ≥10% body weight |
70%1 |
26%1 |
| ≥20% body weight |
26%1 |
2%1 |
Important note about Ozempic doses
The STEP 8 trial used semaglutide 2.4 mg, which is the Wegovy dose for weight management. Ozempic’s maximum dose is 2 mg, and its standard doses are 0.5 mg and 1 mg, both lower than the tested dose.
This means the weight loss shown in STEP 8 reflects what Wegovy can achieve, not Ozempic specifically.
Ozempic at its licensed doses would likely produce less weight loss than the trial figures suggest, though still more than liraglutide, based on the size of the difference.
Liraglutide’s own evidence: the SCALE trial
The SCALE Obesity and Prediabetes trial was the landmark study for liraglutide 3 mg. It enrolled 3,731 adults over 56 weeks and found:3
- -8.0% average body weight loss (vs -2.6% with placebo)
- 63.2% achieved ≥5% weight loss (vs 27.1% with placebo)
- 33.1% achieved ≥10% weight loss (vs 10.6% with placebo)
These results show liraglutide is effective compared with placebo, but less effective than semaglutide at weight-management doses.
Side effects and tolerability
Both medications share similar gastrointestinal side effects, which are typical for all GLP-1 receptor agonists. Liraglutide tends to cause more frequent side effects based on clinical trial data.
| Side effect |
Ozempic (semaglutide) |
Saxenda / Nevolat (liraglutide) |
| Nausea |
~20%4 |
39.3%5 |
| Diarrhoea |
Common during titration4 |
20.9%5 |
| Constipation |
~5%4 |
19.4%5 |
| Vomiting |
Common during titration4 |
15.7%5 |
Liraglutide’s higher rates of gastrointestinal side effects may partly reflect the daily dosing pattern.
Each injection can trigger a new wave of nausea, whereas weekly injections with Ozempic allow side effects to settle between doses.
In the STEP 8 trial, more people stopped liraglutide due to side effects (12.6%) than semaglutide (3.2%).1 This suggests semaglutide is better tolerated despite producing greater weight loss.
Most gastrointestinal side effects with both medications occur during dose escalation and reduce significantly over time.
Safety considerations for both
Neither medication should be used if you have a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
Both medications can affect the absorption of oral medications by slowing gastric emptying. If you take other medications, discuss potential interactions with your prescriber.
Liraglutide has a longer overall safety track record, having been approved for weight management since 2015, compared with semaglutide (Wegovy), which was approved for weight management in 2022.
Practical differences
Injection frequency
One of the biggest practical differences between these medications is how often you inject.
Ozempic is injected once a week on the same day each week. This means 52 injections per year.
Liraglutide (Saxenda/Nevolat) is injected once a day. This means 365 injections per year, roughly seven times as many.
Many people find weekly injections more convenient and easier to maintain long-term than daily ones.
Dosing
Ozempic starts at 0.25 mg weekly for four weeks (a titration phase), then increases to 0.5 mg. Your prescriber may increase further to 1 mg or 2 mg depending on your response.
Liraglutide starts at 0.6 mg daily, increasing by 0.6 mg each week over five weeks until reaching the maintenance dose of 3 mg.
If you can’t tolerate the 3 mg dose, treatment should be discontinued as lower doses aren’t approved for weight management.
Storage
Both medications should be stored in the fridge (2–8°C) before first use. Once in use:
- Ozempic: Room temperature (below 30°C) for up to 56 days
- Liraglutide: Room temperature (below 30°C) for up to 30 days
Neither medication should be frozen. Both can be carried in hand luggage for travel.
Injection technique
Both medications are delivered via pre-filled pens and are injected into the skin of your stomach, thigh, or upper arm.
Rotate injection sites to avoid irritation, which is particularly important with liraglutide given the daily frequency.
Cost and access in the UK
Saxenda has been discontinued
Novo Nordisk has discontinued production of Saxenda to focus manufacturing capacity on newer medications, such as Wegovy.
In the UK, branded Saxenda is now long-term out of stock.
A generic version of liraglutide, called Nevolat (manufactured by Zentiva), is widely available in the UK as a direct replacement.
It contains the same drug at the same doses, so there’s no clinical difference between the two.
If you’re currently taking Saxenda and your supply has been affected, speak with your prescriber about switching to Nevolat, or about whether a different medication might be more appropriate.
Private prescription costs
Costs vary by provider and depend on the dose you’re taking.
Ozempic typically costs £150–250 per month on private prescription, depending on dose and provider.
Generic liraglutide (Nevolat) is typically cheaper, costing between £70 and £160 per month from UK online pharmacies.
NHS access
Ozempic is available on the NHS for type 2 diabetes but can’t be prescribed on the NHS for weight loss.
Liraglutide received NICE approval for weight management (TA664) in 2020, but the criteria are quite narrow.
It’s recommended for adults with a BMI of 35 or above (or 32.5 for certain ethnic backgrounds) plus at least one weight-related condition, and only through specialist weight management services.2
In practice, NHS availability for liraglutide has been limited. Newer medications like Wegovy and Mounjaro are now preferred, with Mounjaro receiving broader NICE approval (TA1026) in 2024.6
Who might prefer each option?
Neither Ozempic nor liraglutide represents the most effective weight-loss treatment currently available.
Newer options like Mounjaro and Wegovy have shown superior results in clinical trials. However, certain factors may make one more relevant to your situation.
Ozempic might be relevant if:
- You have type 2 diabetes – it’s specifically licensed and effective for blood sugar control
- You want a weekly injection – once-a-week dosing is more convenient than daily
- You prefer fewer side effects – lower rates of nausea and gastrointestinal issues compared with liraglutide
Note that if weight management is your primary goal, Ozempic isn’t an appropriate choice as it’s not licensed for this purpose in the UK.
Liraglutide (Nevolat) might be relevant if:
- Cost is a primary concern – generic liraglutide is substantially cheaper than most alternatives
- You’ve previously responded well to liraglutide – if Saxenda has worked for you, switching to Nevolat keeps you on the same medication at a lower cost
- You prefer a medication with a longer safety track record – liraglutide has been used for weight management since 2015, providing over a decade of safety data
- You can’t access newer options – if Wegovy or Mounjaro are unavailable through your provider
For most people seeking weight-loss medication, Mounjaro or Wegovy are now the preferred options. They produce greater weight loss, require weekly injections, and have broader NHS availability.
Frequently asked questions
Is Saxenda still available in the UK?
Branded Saxenda has been discontinued by Novo Nordisk and is no longer being manufactured.
However, a generic version of liraglutide called Nevolat (made by Zentiva) is widely available through UK pharmacies. It contains the same drug and works in exactly the same way.
Is Ozempic better than liraglutide for weight loss?
Semaglutide (the drug in Ozempic) produces significantly greater weight loss than liraglutide in clinical trials. The STEP 8 trial showed semaglutide achieved 15.8% weight loss compared with 6.4% for liraglutide over 68 weeks.1
However, Ozempic uses lower doses than were tested in STEP 8, and it isn’t licensed for weight loss in the UK.
Can I get Ozempic for weight loss in the UK?
No. Ozempic is only licensed for type 2 diabetes in the UK. If you want semaglutide for weight loss, Wegovy is the licensed option. It contains the same drug at a higher dose (2.4 mg vs Ozempic’s maximum 2 mg).
Can I switch from liraglutide to Ozempic?
You could switch from liraglutide to a semaglutide-based medication, but if weight loss is your goal, Wegovy or Mounjaro would be more appropriate than Ozempic.
Because liraglutide is cleared from the body relatively quickly, you can typically start a new medication without a long waiting period, though your prescriber will advise on timing.
Why does liraglutide require daily injections while Ozempic is weekly?
It comes down to how the drugs are designed. Semaglutide was engineered to bind more strongly to albumin (a protein in our blood) and resist breakdown, giving it a half-life of about one week.
Liraglutide was developed earlier and has a shorter half-life of approximately 13 hours, requiring daily dosing.
Are the side effects of liraglutide worse than Ozempic?
Liraglutide generally causes more frequent gastrointestinal side effects. In clinical trials, nausea affected approximately 39% of liraglutide users compared with about 20% of Ozempic users.4,5
The STEP 8 trial found that 12.6% of people stopped liraglutide due to side effects compared with 3.2% for semaglutide.1
Is liraglutide the same as Nevolat?
Yes. Liraglutide is the drug in Nevolat. Nevolat is the brand name for a generic version of liraglutide, replacing the now-discontinued Saxenda. Both contain the same medication at the same concentration.
What is the best weight-loss injection in the UK?
Based on current clinical evidence, tirzepatide (Mounjaro) produces the greatest weight loss of any licensed injectable medication.
In the SURMOUNT-1 trial, the highest dose achieved approximately 22.5% weight loss over 72 weeks. Semaglutide 2.4 mg (Wegovy) is the next most effective option. Both are licensed for weight management in the UK.
Can I take Ozempic and liraglutide together?
No. Both are GLP-1 receptor agonists and should never be combined. Using two GLP-1 medications simultaneously would increase the risk of serious side effects without additional benefit. Your prescriber will recommend one medication based on your health needs.
How long do I need to take liraglutide?
NICE recommends that liraglutide treatment should be reviewed after 12 weeks on the full 3 mg dose. If you haven’t lost at least 5% of your body weight by that point, treatment should be stopped.2
For those responding well, treatment can continue with ongoing monitoring.
Is liraglutide available on the NHS?
Liraglutide received NICE approval (TA664) in 2020 for use through specialist weight management services, but the criteria are narrow, and availability has been limited in practice.2
The NHS is now prioritising newer medications like Mounjaro, which received broader NICE approval in 2024.6
Take home message
Semaglutide (the drug in Ozempic) is more effective than liraglutide (the drug in Saxenda/Nevolat) for both weight loss and blood sugar control.
The STEP 8 trial showed that semaglutide achieved more than twice the weight loss of liraglutide over 68 weeks.1
However, neither Ozempic nor liraglutide is the optimal choice for weight management today. Ozempic isn’t licensed for weight loss in the UK, and liraglutide, while licensed, has been superseded by more effective options. Branded Saxenda has been discontinued, though generic liraglutide (Nevolat) remains available at a lower price.
If you’re looking for weight-loss medication, Mounjaro (tirzepatide) and Wegovy (semaglutide 7.2 mg) are the current first-line options.
Both produce significantly greater weight loss than liraglutide, require only weekly injections, and are approved by NICE for weight management.
Second Nature's Mounjaro and Wegovy programmes
Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.
Why choose Second Nature over other medication providers, assuming you're eligible?
Because peace of mind matters.
We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
References
- Rubino DM, Greenway FL, Khalid U, et al. Effect of weekly subcutaneous semaglutide vs daily liraglutide on body weight in adults with overweight or obesity without diabetes: the STEP 8 randomized clinical trial. JAMA. 2022;327(2):138-150. https://jamanetwork.com/journals/jama/fullarticle/2787906
- National Institute for Health and Care Excellence. Liraglutide for managing overweight and obesity (TA664). 2020. https://www.nice.org.uk/guidance/ta664
- Pi-Sunyer X, Astrup A, Fujioka K, et al. A randomized, controlled trial of 3.0 mg of liraglutide in weight management. N Engl J Med. 2015;373(1):11-22. https://www.nejm.org/doi/full/10.1056/NEJMoa1411892
- Electronic Medicines Compendium. Ozempic 0.25 mg, 0.5 mg, 1 mg solution for injection in pre-filled pen – Summary of Product Characteristics. https://www.medicines.org.uk/emc/product/9748/smpc
- Electronic Medicines Compendium. Saxenda 6 mg/mL solution for injection in pre-filled pen – Summary of Product Characteristics. https://www.medicines.org.uk/emc/product/2313/smpc
- National Institute for Health and Care Excellence. Tirzepatide for managing overweight and obesity (TA1026). 2024. https://www.nice.org.uk/guidance/ta1026
