Not everyone wants a weight loss injection, and not everyone can have one. Some people do not meet the prescribing criteria. Some cannot tolerate the side effects or justify the monthly cost. Some would simply rather not take a long-term medicine.
The alternatives are real, but they are not equal. Surgery produces more weight loss than any medicine. Low-calorie diet replacement programmes can deliver around 10 kg at one year. Standard behavioural programmes and the two licensed non-GLP-1 tablets deliver a few kilograms. Supplements sold as “natural” alternatives deliver very little.
This guide ranks the options by the strength of the human evidence and explains how you get each one in the UK.
One point of definition first. “GLP-1 medicines” here means semaglutide (Wegovy), tirzepatide (Mounjaro, which also acts on a second hormone, GIP), liraglutide (Saxenda) and orforglipron (Foundayo). The tablet forms count too. A pill that acts on GLP-1 is still a GLP-1 medicine, so swapping an injection for the Wegovy pill is a change of format, not a change of approach.
This is information, not medical advice. It cannot tell you which treatment is right for you. That decision belongs with you and a clinician who knows your history. Some outbound links on this site may be referral links; see our editorial policy.
GLP-1 medicines: the benchmark
Any alternative has to be judged against what the injections achieve. In the main trials, people lost around 15% of their body weight with semaglutide and around 20% with tirzepatide. Our peptides guide sets out those trials in detail.
Those numbers come with a condition. They hold while you keep taking the medicine. A 2026 analysis in The BMJ pooled 37 studies and 9,341 people and found that weight returned at about 0.4 kg a month after any weight loss medicine was stopped. After semaglutide or tirzepatide the rate was about 0.8 kg a month.
So the fair comparison is not only how much weight an option removes. It is also how long the result lasts, what it costs to keep, and what happens when you stop. On that fuller comparison, some of the older options look better than their headline numbers suggest.
The alternatives, ranked by evidence
| Option | Typical result in trials | How long it lasts | UK access | Evidence |
|---|---|---|---|---|
| Bariatric surgery (bypass or sleeve) | 19% to 27% of body weight at 3 years (By-Band-Sleeve) | Years, with lifelong follow-up | NHS at BMI 40+, or 35+ with a weight-related condition. Also private | Strong. Large UK randomised trial |
| Endoscopic sleeve gastroplasty | 13.6% at 1 year, against 0.8% with lifestyle advice alone (MERIT) | Most responders held their loss at 2 years. Little data beyond | Varies by area. Often private | Moderate. One randomised trial of 209 people |
| Total diet replacement | 10.7 kg at 1 year, against 3.1 kg with usual care (DROPLET) | Partial regain is usual | NHS programme for recent type 2 diabetes. Commercial programmes | Strong at 1 year. Thinner beyond |
| Behavioural programmes | A few kg at 1 year. 2 to 3 kg at 5 years (WRAP) | Regain is slow | Free NHS digital programme for some. Council and commercial groups | Strong, but the effect is small |
| Naltrexone-bupropion (Mysimba) | About 5 kg more than placebo at 1 year (JAMA, 2016) | While you take it | Private prescription only. Not recommended by NICE for NHS use | Moderate |
| Orlistat (Xenical, Alli) | About 2.6 kg more than placebo at 1 year (JAMA, 2016) | While you take it | GP prescription, or a lower dose from a pharmacy | Strong, but the effect is small |
| Supplements such as berberine | About 1 to 2 kg in small, short trials | Unknown | Sold online and on the high street | Weak |
Two things stand out. The options with the largest effect are procedures, not products. And the options that are easiest to buy are the ones with the least evidence.
Surgery: the most effective option, and the most demanding
The best UK evidence is the By-Band-Sleeve trial, published in 2025. It randomised 1,346 patients across 12 NHS hospitals to one of three operations. Three years later, average weight loss was 26.8% after gastric bypass, 19.4% after sleeve gastrectomy and 14% after gastric band. No deaths were attributed to surgery. The researchers recommend bypass first, sleeve where bypass is not possible, and say the evidence does not support the band as standard treatment.
NICE says adults should be offered an assessment for surgery if they have a BMI of 40 or more, or 35 to 39.9 with a significant health condition that weight loss could improve. The thresholds are 2.5 points lower for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds. Since 2023 you no longer need to have tried every non-surgical option first.
The commitment is real. NICE expects you to agree to long-term follow-up, which can mean annual reviews for life. If you are considering surgery abroad, ask who will provide that follow-up when you come home.
One gap in the evidence: nobody has yet run a head-to-head trial of surgery against the newer injections. The By-Band-Sleeve team has called for one.
Endoscopic sleeve gastroplasty: promising, less proven
This procedure reduces the size of the stomach with stitches placed through the mouth, with no external cuts. In the MERIT trial, 209 adults with a BMI of 30 to 40 were randomised to the procedure plus lifestyle changes, or lifestyle changes alone. At one year the procedure group had lost 13.6% of their body weight against 0.8%. Serious complications occurred in 2% of patients.
That is a good result from a single trial, which was part-funded by the device manufacturer. Long-term data are limited. Treat it as a credible option with a shorter track record than surgery.
Total diet replacement: large early losses, then the hard part
Total diet replacement swaps all meals for formula soups and shakes, usually around 800 calories a day, for 8 to 12 weeks. Food is then reintroduced in stages with regular support.
In the DROPLET trial, 278 adults with obesity were referred by their GP to a programme like this or given usual care. At 12 months the programme group had lost 10.7 kg against 3.1 kg, and 45% had lost more than a tenth of their body weight.
The DiRECT trial used the same approach in people with type 2 diabetes. Almost half were in remission at one year. The five-year follow-up is the sobering part. Among those who stayed in the programme with continued support, average weight loss was 6.1 kg and 13% were still in remission.
Regain is the rule here too, which is why DiRECT built in “rescue plans” that restarted the formula diet if weight crept up by more than a set amount. In England the NHS offers this approach through the Type 2 Diabetes Path to Remission Programme. Do not attempt it unsupervised if you take medicines for diabetes or blood pressure, because doses usually need to change.
Behavioural programmes: small effect, slow regain
These are structured programmes of diet, activity and habit change, delivered in groups or by app. The WRAP trial randomised 1,267 UK adults to a commercial group programme for 12 weeks, the same programme for 52 weeks, or a self-help booklet. Five years on, average weight loss from the start was 2.7 kg with the 52-week programme, 2.0 kg with the 12-week programme and 0.5 kg with the booklet. By then the gap between groups was no longer statistically significant.
That is a small effect. It has two things in its favour. It costs little or nothing, and the BMJ analysis found weight returned more slowly after behavioural programmes than after medicines.
The NHS Digital Weight Management Programme is free. It is a 12-week online programme for adults living with obesity who also have diabetes, high blood pressure or both. A GP practice or community pharmacy can refer you.
Tablets that are not GLP-1 medicines
Two are licensed in the UK.
Orlistat stops the gut absorbing some of the fat you eat. Across 17 trials it produced about 2.6 kg more weight loss than placebo at one year. Eating fatty food while taking it causes oily stools and urgency, which is unpleasant and is also part of how it changes behaviour. NICE says it can be prescribed at a BMI of 30 or more, or 28 or more with risk factors, and should be stopped if you have not lost 5% of your weight after 12 weeks. A lower-dose version is sold in pharmacies.
Naltrexone-bupropion (Mysimba) acts on appetite and reward pathways in the brain. Across five trials it produced about 5 kg more weight loss than placebo at one year. People taking it were also more likely than those on placebo to stop because of side effects. NICE decided in 2017 not to recommend it for NHS use, saying its long-term effectiveness was unknown and its cost-effectiveness too uncertain. It is available on private prescription.
Neither tablet comes close to the injections. Be wary of any site that markets “weight loss pills” without naming the active ingredient.
Supplements and “nature's Ozempic”
Berberine is the supplement most often sold as a natural alternative. Pooled analyses of randomised trials put its effect at roughly 1 to 2 kg. The trials were small, and most ran for four months or less. Nobody has tested whether the effect lasts.
That is about a tenth of what the licensed injections achieve, from a product that is not checked for quality the way a medicine is. A nickname is not evidence.
How to choose
Your starting point narrows the list quickly.
- BMI of 40 or more, or 35 or more with a weight-related condition. Ask your GP about an assessment for surgery. It is the option with the largest and longest-lasting effect, and you do not need to have exhausted everything else first.
- Type 2 diabetes diagnosed in recent years. Ask whether you qualify for the NHS Path to Remission Programme.
- Obesity with diabetes or high blood pressure. The NHS Digital Weight Management Programme is free and needs only a referral.
- You want a tablet that is not a GLP-1. Orlistat is the one the NHS prescribes. Go in knowing the likely effect is a few kilograms.
- You are looking at supplements. The money is better spent on almost anything else in this guide.
These options are not mutually exclusive, and they are not a rejection of medicine. NHS prescribing of weight loss injections comes with a diet and activity programme attached, because the two work better together.
The bottom line
There are effective ways to lose weight without a GLP-1 medicine. The most effective ones are surgery and supervised diet replacement, and both ask a lot of you. The easiest ones to start, behavioural programmes and orlistat, produce modest results that tend to last. Nothing sold as a supplement has evidence worth paying for.
If an alternative is marketed as matching the injections without a prescription, a procedure or sustained effort, the honest answer is that the evidence does not support it.