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How quickly do you lose weight on Zepbound?

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

5 min read
Last updated February 2024

Jump to: How effective is Zepbound for weight loss? | Is Zepbound available in the UK? | Is Zepbound available on the NHS? | Can I buy Zepbound in the UK? | How much does Zepbound cost in the UK? | Which is better, Wegovy or Zepbound? | Does Zepbound have side effects?

According to randomised controlled trials, you start losing weight immediately after taking Zepbound. After four weeks, the average weight loss is around 2% of body weight; after eight weeks, it’s over 4%.

Zepbound (tirzepatide) reduces appetite and hunger, helping you eat fewer calories; this effect is almost immediate.

However, you might notice the impact of lower hunger wearing off after 4-5 days post-injection in the first month of taking Zepbound.

It can take around four weeks for Zepbound to reach a level in the body we call a steady state. A steady state is when the drug’s levels in the body remain consistent rather than spiking and falling.

Interestingly, this initial weight loss is no different to other weight loss treatments or the impact of diet interventions on weight loss. The real effect of tirzepatide is seen beyond three months.

Tirzepatide is a long-acting medication that’s started at a lower dose to reduce the number and severity of side effects as it’s built up to a higher maintenance dose.

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How effective is Zepbound for weight loss?

Research suggests that Zepbound leads to an average weight loss of around 25% after one year. If you weighed 100 kg, that would be a weight loss of 25kg.

This research also showed the percentage of participants on Zepbound achieving more than 10% weight loss is incredibly high. 92% of participants on Zepbound achieved more than 10% weight loss, with 84% achieving more than 15%.

Achieving over 10% weight loss is associated with clinically significant reductions in risk of chronic conditions such as type 2 diabetes and heart disease.

Is Zepbound available in the UK?

Zepbound has been approved for weight loss and type 2 diabetes in the UK under the brand name Mounjaro and will be available by early 2024. It was approved for type 2 diabetes in September 2023 and weight loss in November 2023.

However, it can take some time after approval for these medications to become available through pharmacies and the NHS.

In the U.S., tirzepatide is available as Mounjaro for people living with type 2 diabetes and Zepbound for people living with obesity. They’re the same drug but sold under different brand names.

However, in the UK, it will only be sold under the brand name Mounjaro.

Is Zepbound available on the NHS?

You can’t get Zepbound on the NHS yet, and it’s unclear when it will be prescribed through the NHS.

It may only be available as a private prescription before becoming more widely available on the NHS through specialist weight management services.

However, Zepbound’s approval for weight loss has only just been announced (as of November 2023), so it’s unclear what approach the NHS will take on providing Zepbound to patients.

Can I buy Zepbound in the UK?

You can buy Zepbound from pharmacies, approved online retailers, and specialist weight-loss programmes in the UK.

Second Nature plans to make Zepbound/Mounjaro available to purchase alongside our NHS-trusted weight-loss programme as early as February 2024.

However, you must meet strict eligibility criteria and complete an initial consultation with our clinical team.

How much does Zepbound cost in the UK?

If you’re prescribed Zepbound via the NHS, you’ll only need to pay the base fee of £9.95 for a prescription.

Via private prescription, buying Zepbound and the injectable pens required for four weeks would cost around £300 with Second Nature when it’s available.

Which is better, Wegovy or Zepbound?

The higher doses of Zepbound (10mg & 15mg) are more effective for weight loss and blood sugar than Wegovy, based on an indirect analysis of individual studies.

Zepbound supports an average weight loss of around 25% after one year, whereas on Wegovy, it’s around 16%.

However, no studies have compared the two medications directly against one another in a double-blinded randomised controlled trial (where neither the researchers nor the participants know which medication they’ve been given).

So, Zepbound seems more effective than Wegovy for weight loss, but we need a study comparing the two weight-loss injections to confirm this.

Does Zepbound have side effects?

The most common side effects of Zepbound are nausea, constipation, vomiting, and other symptoms affecting the gastrointestinal (GI) tract, like diarrhoea.

You might also experience less common side effects like tiredness or headaches.

These symptoms most commonly occur around the time of the injection, during dose escalation, and are typically transient and will ease after you’ve adapted to the medication.

However, everyone responds differently to these medications; some people won’t experience any side effects, while others will have to discontinue their medication due to the discomfort the side effects cause.

Not a magic pill

Weight loss injections are designed as additional tools for weight management interventions and shouldn’t be considered lifelong medications.

Instead, they should be used to help you kickstart your weight loss and healthy journey while you commit to living a healthier lifestyle.

Consider the use of antidepressants for people living with depression. They’re not designed to cure the condition. Instead, they’re designed to allow room for therapy to treat the condition’s underlying cause.

Zepbound, and other weight loss injections, like Wegovy, are similar. They can calm down the food noise to help you find your eating off switch, allowing you the time and energy to build healthier habits to keep the weight off for good.

At Second Nature, we’ve been used by the NHS since 2017 to support people with type 2 diabetes and obesity to lose weight, manage their blood sugar levels, and lead healthier lifestyles for the long term.

Ideally, we’d lose weight without medication, and we’d recommend trying our weight-loss programme before trying a weight-loss injection, as it’s cheaper and potentially more sustainable in the long term.

In 2022, the NHS published data in the BMJ that compared the weight loss outcomes of five providers in the National Diabetes Prevention Programme.

Second Nature was more than twice as effective at supporting weight loss than the other four providers.

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