Weight loss injections vs tablets: usage, efficacy, cost

Choosing between weight loss injections and tablets isn’t always straightforward. Both options are widely used and medically approved, but they differ in how they work, how you take them, and the results you can expect.

With newer treatments continuing to expand what’s available it’s becoming increasingly important to understand how each approach fits into your weight loss journey.

Below, we break down the key differences to help you compare your options and decide what might work best for you.

Key points

• Weight loss injections tend to have shown higher average weight loss in clinical trials but can be more expensive.
• Tablets are an alternative for weight loss maintenance or for those who don't like needles
• New tablets under development are beginning to bridge the gap between convenience of tablets and efficacy of injections.

Weight loss injections and tablets at a glance

What’s the difference between weight loss injections and tablets?

Weight loss injections and tablets both help you lose weight, but they work in different ways and deliver different results.

Understanding the differences can help you choose the option that best fits your lifestyle, goals, and eligibility.

How they work

Weight loss injections and tablets target weight loss in very different ways, as they all have different active ingredients and belong to different drug classes.

Weight loss injections like Wegovy, Mounjaro and Saxenda all belong to a group of medicines known as GLP-1 receptor agonists. They work by copying a hormone produced in the gut to regulate blood sugar, slow digestion and reduce appetite. Wegovy tablets also fall into this category, and work in the same way.

Other weight loss tablets work slightly differently, depending on which one you choose. Orlistat (Xenical/Alli/Orlos) capsules work by blocking the chemicals in your gut that digest fats, meaning they’re not stored and instead get passed when you go to the toilet.

Mysimba on the other hand works by targeting the areas of the brain that are that control and manage appetite, helping clear food noise and making it easier to stick to a calorie-controlled diet.

How you take them

Most weight loss injections are taken once a week using a pre-filled pen under the skin, making them a lower-maintenance option if you’re okay with needles. However, some injections (like Saxenda) are taken daily instead.

Currently tablets need to be taken every day. Orlistat-based pills are taken 3 times a day with meals, while Mysimba gradually increases from 1 tablet in the morning to 2 tablets twice a day.

However, there are currently two oral weight loss treatments, Wegovy pills and Foundayo, that have been approved in the USA and are awaiting approval in the UK. Both are taken once a day, with Foundayo having no timing or food and drink restrictions during clinical trials.

If approved in the UK, they will make tablets another option for those looking to take weight loss medication.

Effectiveness

While both options can help you on your journey, on average, in clinical trials injections tended to lead to greater weight loss than tablets.

Newer injectable treatments like Wegovy and Mounjaro may help patients lose around 21-25% total weight loss on average, while older treatments like Saxenda generally lead to weight loss of roughly 5-10%.

Tablets tend to offer more moderate results, with most treatments (like orlistat and Mysimba) leading to around 5–10% weight loss on average.

Wegovy tablets have shown weight loss closer to 14% in clinical trials, making them more comparable to once weekly injections.

It’s important to remember that these results are averages from clinical trial settings, and individual results can vary.

Side effects

Weight loss injections and tablets can both cause side effects, but they tend to affect the body in slightly different ways.

Injections are more likely to cause digestive side effects, particularly when starting treatment, like:

• nausea
• diarrhoea
• constipation

There’s also a chance of skin irritation around where you choose to inject your treatment.

You can find out more by reading our guides on Wegovy side effects and Mounjaro side effects.

Tablet side effects vary depending on how the treatment works. Some, like orlistat, can cause gut-related effects (like changes to your bowel habits), while others like Mysimba work in the brain, which may lead to symptoms like headaches or dizziness.

Most side effects are mild and improve over time as your body adjusts, but the type and severity can vary depending on the treatment you’re using.

They don't affect everyone, and most people find them manageable. Your prescriber will be able to help if you're struggling.

Price

While prices vary depending on what your chosen pharmacy, below is an indication of how much you’ll pay for your weight loss treatment:

• Mounjaro - £169 - £309
• Wegovy - £119 - £279
• Saxenda – approx. £375 - £750
• Generic orlistat - £33.59 for one months’ supply
• Xenical - £45.99 for one months’ supply
• Mysimba - £99.99 for one months' supply

Wegovy tablets are still being reviewed by the Medicines and Health product Regulatory Agency (MHRA), meaning we currently don’t know what the price will be compared to injections.

All prices listed are subject accurate at the time of writing this article, though could be subject to change in the future.

Eligibility

Most prescription weight loss injections, like Mounjaro, Wegovy, and Saxenda, are only available after a consultation.

On the NHS, they’re usually offered to people with:

• a BMI of 35 or higher and one or more weight related health conditions

Privately, eligibility is often broader for injections, with the main requirement usually being:

• a BMI of 30 or higher (27 or higher depending on ethnic background)

Prescription options like Mysimba follow similar BMI criteria, while orlistat may also be available over the counter in addition to a consultation. It’s available at a lower dose (Alli, Orlos), typically for people with a BMI of 28 or above.

Can you switch from weight loss injections to tablets?

Yes, you can switch from weight loss injections to tablets, whether it be because you’re looking for a different way to manage your weight, or a needle-free treatment plan.

Tablets are a valid alternative to help you continue your weight loss journey, but if you’re considering making any changes to your current treatment plan, then you should always discuss this with your prescriber first. They will be able to help guide you through the transition, and what you can expect.

Frequently asked questions about weight loss injections vs tablets

What’s the most effective weight loss treatment?

In clinical trials, weight loss injections have tended to lead to greater average weight loss than tablets, particularly newer treatments like Mounjaro and Wegovy. However, tablets can still be effective, especially for people who prefer a non-injectable option.

Do weight loss tablets actually work?

Yes, weight loss tablets can be effective when used alongside a healthy diet and regular exercise.

Most treatments, like orlistat and Mysimba, can help people lose around 5–10% of their body weight on average, although results vary depending on the medication and how consistently it’s taken.

What’s the strongest prescription weight loss pill?

Among currently available prescription weight loss tablets, options like orlistat and Mysimba are the ‘strongest’ in terms of effectiveness.

These treatments are effective for many people but tend to offer more moderate weight loss compared to newer options like injections.

There are also newer tablet treatments in development like Wegovy tablets, which have shown average weight loss of around 14% in clinical studies. These may offer a more effective tablet-based option once they become widely available.

Ultimately, there is no single ‘strongest’ or ‘best’ weight loss tablet. It depends on how your body reacts to the treatment, and what you’re looking to get from it.

Summary of weight loss injections vs tablets

“When it comes to choosing between weight loss injections and tablets, there isn’t a one-size-fits-all answer. It really depends on what’s right for your body, your goals, and where you are in your weight loss journey.

“Injections can be a good option if you’re looking for more significant weight loss or haven’t seen results with other treatments. Tablets, on the other hand, can be easier to take day-to-day and may be a better fit if you prefer a non-injectable option or are thinking about longer-term treatment.

“What matters most is finding something you can use consistently and feel comfortable with. A healthcare professional can help you weigh up your options and choose the treatment that best supports your needs.”

Ayesha Bashir, weight loss expert at myBMI

Sources

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• Evaluation of efficacy and safety of orlistat in obese patients. PubMed. [Accessed 19 May 2026]
• Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity. NEJM. [Accessed 19 May 2026]
• Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial (2025). PubMed. [Accessed 19 May 2026]
• Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (2025). PubMed. [Accessed 19 May 2026]
• Alli (previously Orlistat GSK). EMA. [Accessed 19 May 2026]
• Orlistat 60 mg Reduces Visceral Adipose Tissue: A 24-Week Randomized, Placebo-Controlled, Multicenter Trial. Wiley Online Library. [Accessed 19 May 2026]