Wegovy pill results: what the OASIS trials found
The licensed 25 mg Wegovy pill was tested in the OASIS 4 trial, published in the New England Journal of Medicine in 2025. This page gives the exact figures, a realistic timeline and the limits of the evidence.
In short: In the OASIS 4 trial, adults taking the 25 mg Wegovy pill once a day lost an average of 13.6% of body weight over 64 weeks, compared with 2.2% on placebo. Among people who stayed on treatment, the average was 16.6%. In total, 76.3% lost at least 5%, 59.8% at least 10% and 47.0% at least 15%. Everyone also followed a reduced-calorie diet and increased activity.
OASIS 4: the trial of the licensed 25 mg dose #
OASIS 4 enrolled 307 adults with a BMI of 30 or more, or 27 or more with a weight-related condition. None had diabetes. The trial gave 205 people the Wegovy pill and 102 people a placebo for 64 weeks, including a 12-week dose escalation. Both groups received diet and physical activity support. The average starting weight in the tablet group was 106.4 kg, with an average BMI of 37.5.
| Measure | Wegovy pill 25 mg | Placebo |
|---|---|---|
| Average weight change, everyone randomised | 13.6% loss | 2.2% loss |
| Average weight change, if taken as directed | 16.6% loss | 2.7% loss |
| Average weight change in kg | 14.2 kg loss | 2.2 kg loss |
| Lost 5% or more | 76.3% | 30.5% |
| Lost 10% or more | 59.8% | 14.1% |
| Lost 15% or more | 47.0% | 5.4% |
| Lost 20% or more | 27.5% | 3.0% |
| Waist reduction | 12.2 cm | 2.8 cm |
Results vary from person to person. Roughly 1 in 4 people on the tablet did not reach a 5% loss, and no clinic can promise you a figure.
Why the paper gives two average figures #
The 13.6% figure counts everyone who started the trial, including people who stopped the tablet early. In OASIS 4, 18% of the tablet group stopped treatment before the end. This figure shows what happens across a real group of people.
The 16.6% figure estimates the result if everyone had stayed on the tablet as directed. This is closer to what a person who takes every dose correctly may expect. On a starting weight of 100 kg, the two averages equal 13.6 kg and 16.6 kg.
OASIS 1 tested 50 mg, a dose not licensed in the UK #
You will see OASIS 1 quoted for the Wegovy pill. OASIS 1, published in The Lancet in 2023, tested a 50 mg tablet in 667 adults over 68 weeks. Average weight loss was 15.1%, compared with 2.4% on placebo, and 85% of people lost at least 5%.
The UK product information for the Wegovy pill lists 25 mg as the maintenance and maximum dose. OASIS 4 is the trial for this dose, so the OASIS 4 figures are the ones relevant to your treatment.
How the results compare with the Wegovy injection #
No trial has compared the tablet with the injection directly. In the separate STEP 1 trial, the 2.4 mg Wegovy injection produced an average loss of 14.9% over 68 weeks, compared with 2.4% on placebo. The 25 mg tablet produced 13.6% over 64 weeks in OASIS 4. The trials differ in size and length, so the figures sit in the same range without proving one form is better.
Your choice may come down to routine. Read Wegovy tablets vs pen and pills vs pens, or compare all four medicines on the weight loss plans page.
A month-by-month expectation #
The product information says weight loss in OASIS 4 started early and continued throughout the trial. The published summary gives no average for each month, so the table describes the stage of treatment and avoids invented numbers.
| Stage | Dose | What to expect |
|---|---|---|
| Month 1 | 1.5 mg | Starter dose. Appetite changes are often mild. Your routine matters more than the scales. |
| Month 2 | 4 mg | Fullness after meals becomes more noticeable for many people. Side effects can flare after the increase. |
| Month 3 | 9 mg | Appetite control strengthens. Weight loss is usually easier to see. |
| Month 4 | 25 mg | First month on the full dose. Blood levels take 4 to 5 weeks to settle. |
| Months 5 to 15 | 25 mg | The period in which the trial averages built up. The headline figure was measured at 64 weeks. |
Judge progress over months. A fair early marker is whether you have lost weight steadily by the end of month 4, when you have reached the full dose. The first month on the Wegovy pill guide covers the starter weeks in detail.
What slows results #
- Breaking the dosing rules. Only about 1% to 2% of each tablet is absorbed, and food, coffee, a large glass of water or a wait under 30 minutes cut absorption further. Check your technique in how to take the Wegovy pill.
- Missed tablets. The 16.6% figure reflects people who stayed on treatment.
- Staying on a low dose. The trial results come from 25 mg.
- Eating too little protein and doing no resistance exercise, which risks losing muscle along with fat. See the exercise guide.
- Regular alcohol and high-calorie drinks, which add energy without filling you up.
Weight loss also slows naturally after several months. The weight loss plateau guide explains what to adjust.
What the Wegovy pill has not been shown to do #
- Keep weight off after you stop. Evidence from the injection trials shows weight returns after stopping semaglutide. In the STEP 1 extension, average weight rose once treatment stopped, and the semaglutide group ended 5.6% below starting weight. Plan ahead with the weight loss maintenance guide.
- Cut heart attack and stroke risk in a tablet trial. The SELECT trial, which found a 20% lower rate of major heart events, used the semaglutide injection in adults aged 45 or over with existing heart disease.
- Work without lifestyle change. Every OASIS 4 participant had diet and activity support.
- Treat people with type 2 diabetes for weight loss in OASIS 4. The trial excluded people with diabetes.
- Beat the injection. No head to head trial exists.
Wegovy pill results: what the OASIS trials found: questions #
How much weight can you lose on the Wegovy pill?
Aero’s treatment prices are not yet confirmed. Before paying, ask for the total price, pack quantity, prescribing fees, dispensing and delivery charges, and follow-up costs. Use your provider’s written quote in the cost planner.
How long does the Wegovy pill take to work?
Weight loss in OASIS 4 began early and continued through the 64 weeks. The first three months use lower escalation doses of 1.5 mg, 4 mg and 9 mg, so many people notice stronger effects from month 4, when the dose reaches 25 mg.
Is the Wegovy pill as effective as the injection?
No trial has compared the two directly. In separate trials, the 25 mg tablet gave an average loss of 13.6% over 64 weeks in OASIS 4, and the 2.4 mg injection gave 14.9% over 68 weeks in STEP 1. The results are in a similar range.
Which OASIS trial tested the 25 mg Wegovy pill?
OASIS 4 studied the 25 mg tablet over 64 weeks. It included 307 adults and was published in 2025. OASIS 1 studied a different, 50 mg dose; its results should not be presented as results for the UK licensed 25 mg maintenance dose.
What percentage of people lose 10% on the Wegovy pill?
In OASIS 4, 59.8% reached at least 10% weight loss. That compares with 14.1% taking placebo at week 64. The result concerns the studied 25 mg tablet regimen and trial population; it is not a forecast of your individual response.
Wegovy pill plan price to be confirmed
Aero’s treatment prices and service inclusions will be confirmed before booking opens. Ask which prescribing, dispensing, delivery and follow-up costs are included in your quote.
Page information
- Summary
- Wegovy pill results from the OASIS 4 trial: 13.6% average weight loss over 64 weeks on 25 mg, and 16.6% in people who took every dose. Full figures inside.
- Publisher
- Aero Clinic, operated by AERO HEALTHCARE LTD.
- Editorial update
- Clinical review
- Pending. An editorial update is not a clinical sign-off.
Cite as: Wegovy pill results: what the OASIS trials found, Aero Clinic (https://www.cagri.co.uk), AERO HEALTHCARE LTD. https://www.cagri.co.uk/wegovy-pill-results. Editorial update: 4 November 2026. Clinical review pending.