Could Weight-Loss Maintenance Injections Eventually Be Monthly?

For many people using weight-management treatment, reaching their target weight is only part of the journey. One of the biggest questions is what happens afterwards: do you need the same treatment, at the same dose and frequency, forever?

New research released on 22 September 2026 has attracted attention because an experimental obesity medicine called VK2735 was able to maintain much of the weight participants had already lost when injections were given less frequently.

What is VK2735?

VK2735 is an investigational medicine being developed by Viking Therapeutics. Like tirzepatide, the active ingredient in Mounjaro, it targets both the GLP-1 and GIP receptors, which are involved in appetite, fullness and metabolic regulation.

It is currently being studied as both an injectable and oral treatment and is not currently an approved weight-management medicine in the UK.

What did the new maintenance study find?

Around 180 adults living with obesity entered the study.

Participants receiving VK2735 initially had once-weekly injections for 21 weeks. During this phase, average weight reduction in the treatment groups was approximately 16–19%.

Researchers then investigated what happened when treatment became less frequent.

For a further 12 weeks, some participants received injections every other week, some received them once every four weeks, while others were switched to placebo.

Participants using every-other-week maintenance regimens retained up to 97% of the weight loss they had achieved during weekly treatment.

Those receiving monthly treatment retained up to 90%.

In comparison, participants switched to placebo retained around 61% of their previous weight loss.

Does this mean Mounjaro or Wegovy can be taken monthly?

No - and this is the most important point.

This study involved VK2735, not Mounjaro (tirzepatide), Wegovy (semaglutide) or Foundayo.

The maintenance phase also lasted only 12 weeks, and these are preliminary topline results released by the manufacturer rather than a full peer-reviewed publication.

The findings therefore should not be interpreted as evidence that patients can stretch the dosing interval of their existing medication to every two weeks or once monthly.

Patients should continue to use their current medicine according to the regimen agreed with their prescriber.

Why is the study still interesting?

The results point towards an important direction in obesity research.

Obesity is increasingly recognised as a condition where long-term weight maintenance matters as much as the initial weight loss.

For many patients, the ideal maintenance approach may not necessarily be the highest treatment dose indefinitely. Researchers are now examining whether different doses, formulations and dosing frequencies could maintain the benefits of treatment while reducing treatment burden.

VK2735 is just one experimental approach, and significantly more evidence is required before we know whether less frequent maintenance treatment becomes part of routine clinical practice.

Weight maintenance should be individualised

There is no single maintenance strategy that suits everybody.

Some patients may continue to benefit from treatment over the longer term, whereas others may require dose adjustment depending on appetite, food noise, weight stability, side effects, nutrition, muscle mass and their individual risk of weight regain.

The important distinction is between clinically supervised maintenance and independently changing how a prescribed medicine is taken.

How Pharmulous can help

At Pharmulous, we view maintenance as an important part of the weight-management journey rather than simply stopping treatment once a target weight has been reached.

Our clinicians can review your previous treatment, current weight and BMI, food noise, tolerability, lifestyle and risk of weight regain and discuss an appropriate long-term strategy using currently licensed treatment options.

Our aim is a patient-centred approach focused on maintaining health and weight stability while using the lowest appropriate effective treatment strategy, where clinically suitable.

As newer medicines such as VK2735 progress through clinical trials, we will continue to review the evidence and explain what new research genuinely means for patients and, equally importantly, what it does not yet mean.