Wegovy Vs. Orlistat: What's The Difference?
Wegovy
Obesity is a major public health concern, with the condition responsible for at least 2.8 million deaths each year.
Excess weight can lead to a number of diseases, including cardiovascular disease which itself is a leading cause of death worldwide.
Since the number of people living with obesity is increasing, there has been an increase in the amount of research for effective weight loss treatments such as Wegovy and Orlistat.
Both treatments are prescription only (POM), though a lower dose version of orlistat is available over-the-counter. Both treatments are available following an online consultation from our GPhC registered online pharmacy.
Here we’ll discuss the differences between the two treatments, and who may be better suited to one treatment over the other.
Remember, whilst medication can be an effective tool, making sustainable lifestyle changes is perhaps even more important when considering long-term weight loss.
What is Wegovy?
Wegovy is a once-weekly injectable medication containing the active ingredient semaglutide. Known as a GLP-1 agonist, Wegovy works by:
Slowing digestion
Increasing fullness after eating and,
Regulating blood sugar levels.
The combination of this can help keep you feeling fuller for longer throughout the day, whilst minimising food cravings. This then leads to less food being consumed and thus weight loss.
What is Orlistat?
Orlistat is an oral medication, taken three times daily. It works by
Reducing dietary fat absorption, by a third.
By reducing fat absorption, less calories are absorbed, leading to weight loss.
Who Can Take the Treatments?
Both treatments are licensed for use in adults over 18 years with:
A BMI (body mass index) of 30 or above
A BMI of 27 or above, with a weight related health condition.
A weight-related health condition is any health issue which is caused by or made worse by carrying excess body fat, such as:
Type 2 diabetes
Coronary heart disease
High blood pressure
Sleep apnoea
Some cancers
How Do I Take The Treatments?
Wegovy
Wegovy is administered as a once-weekly injection. It must be started at the initiation dose of 0.25mg. The dose is then increased in 4-weekly intervals until you reach a dose which offers a balance of effectiveness and tolerability.
Orlistat
Prescription strength capsules contain 120mg Orlistat. One capsule should be taken three times daily, with meals.
Alongside treatment, patients are recommended to make lifestyle adjustments, specifically:
Reducing fat content in meals
Increasing fibre intake
Side Effects
Wegovy
As with any medication, Wegovy can cause side effects though not everyone gets them.
The most common side effects of Wegovy include:
Nausea
Headaches
Diarrhoea
Constipation
Rarer side effects, requiring immediate medical attention include:
Pancreatitis - severe stomach pain, spreading to the back or chest, with fever/nausea
Gallstones - severe abdominal pain, yellowing of the eyes/skin
Severe allergic reaction - swelling of the face, lips, throat, difficulty breathing.
Orlistat
The most common side effects of taking Orlistat are:
Oily stools/poo
Stomach pains
Diarrhoea
Needing to go toilet urgently
If you're experiencing any worrying side effects, seek medical help.
Comparison of treatments
So what is the best weight loss medication? Whilst the treatments have not been compared in direct head-to-head trials, data from independent trials conclude Wegovy may produce greater weight loss.
The main differences between the two treatments has been highlighted below:
Feature | Wegovy (semaglutide) | Orlistat |
|---|---|---|
How It Works | Mimics GLP-1 hormone Slows digestion Increases fullness levels Regulates blood sugar levels | Blocks lipase enzyme Reduces up to 30% fat absorption |
How To Take The Treatment | Once-weekly injection | Oral capsule, taken three times daily |
Effectiveness | High - 83% lost ≥5% body weight Average weight loss of ~15% over 68 weeks | Moderate - 50% lost ≥5% body weight |
Common Side Effects | Nausea and vomiting Diarrhoea Constipation | Oily stools Flatulence with oily discharge Urgent bowel movements Stomach pain |
Does it Affect Nutrition? | No, though calorie intake reduces | Yes, reduces absorption of fat-soluble vitamins (A,D,E, K) |
Multivitamin Required? | Generally no, though advised | Yes, particularly fat-soluble vitamins (A,D,E, K) |
Who Cannot Take (Contraindicated) | Medullary Thyroid Carcinoma (MTC) Multiple Endocrine Neoplasia type 2 (MEN2) | Chronic malabsorption syndrome Cholestasis |
Dietary Focus | Portion control | Low fat diet - less than 30% |
Medical Emergencies | Severe allergic reaction Pancreatitis Gallstones | Severe allergic reaction Severe liver injury Acute kidney injury |
Available OTC | No | OTC version available |
Monthly Cost | £130 - 300 | ~£45 |
Summary
Whilst both treatments offer advantages, which one you decide to embark on is a personal decision based on individual goals.
Wegovy is recommended for those who have greater weight to lose, as clinical trial data points to it being more effective. More patients on Wegovy lost 5% weight, lowering their risk of type 2 diabetes, blood pressure and cholesterol levels.
Regarding side effects, with Wegovy, these occur regardless of what you eat as the body adjusts to treatment. With Orlistat, side effects can be minimised through making behavioural changes, i.e. reducing consumption of high fat foods.
Orlistat may be easier to take as an oral capsule, however it must be taken three times a day, everyday. Wegovy, whilst requiring proper injection technique, only needs to be administered once weekly.
Other factors to consider include:
Cost
Pre-existing medical conditions
Any medication you're already taking
Whether you're happy to inject yourself every week
Your BMI
Your family history (especially of thyroid cancer)
Professional medical advice
Prior to starting any treatment, it’s important to seek medical advice. Quick Meds offers weight loss consultations with GPhC registered clinicians who can recommend the most appropriate treatment for you.
Frequently Asked Questions
Everything you need to know
Can I take Wegovy and Orlistat together?+−
No, the treatments must not be taken together. Both treatments work through different mechanisms. Taking them together has not been studied for clinical safety and can significantly increase the risk of side effects.
How much weight can I expect to lose on Wegovy vs. Orlistat?+−
Clinical trials demonstrate Wegovy users experience greater weight loss.
On average, those using Wegovy lost ~15% body weight in 68 weeks compared to independent orlistat studies showing roughly 5% weight loss over a similar period.
Why do I need a multivitamin with Orlistat but not Wegovy?+−
Orlistat blocks roughly 30% of dietary fat absorption. As vitamins A,D,E and K are fat-soluble, they need fat to be absorbed sufficiently.
Wegovy does affect fat absorption and thus does not affect vitamin absorption the way Orlistat does.
Is the Wegovy injection painful?+−
Most users find the injection painless as only a small needle is used to inject just below the skin, feeling only a ‘sharp scratch’.
Can I buy the treatments over-the-counter in the UK?+−
Wegovy is a prescription only treatment and cannot be bought over-the-counter.
Orlistat at the higher 120mg strength is also prescription only. However, a lower dose version, containing 60mg is available as the Alli brand over the counter following a pharmacist consultation.
Are the treatments available on the NHS?+−
Orlistat is widely available through your GP.
Wegovy, is restricted to patients through Tier 3 weight management services, usually through a specialist and is not usually prescribed by the GP.
