The National Pharmacy Association chair, Olivier Picard, has said that weight loss jabs may be effective, but it is not a 'silver bullet', and lifestyle changes are required to sustain a healthy weight.
He was responding to a report by the University of Oxford on the long-term effectiveness of weight loss treatments.
The study found that people on weight loss drugs regain all the weight they have lost within a year of stopping the medication.
Picard termed obesity as the "single biggest health challenge" being faced by the UK.
"Although weight loss treatment can help some people to achieve a healthy weight who may have struggled in the past by simply making lifestyle changes, patients should understand it is not a silver bullet.
"As this study shows, without sustained lifestyle changes, weight loss and the subsequent health benefits will not be sustained.
"It's really important that patients who are using this treatment are given full wrap-around support by their pharmacy to make the long-term changes to diet and exercise they need to maintain a healthy weight."
Weight-loss injections mimic hormones in the patient's body and slow down digestion, lowering appetite. This helps them eat less and lose weight.
But when they stop taking the drug, their appetite returns to normal, and some people start eating more and regain the weight they lost while taking the drug.
In the UK, the NHS offers weight loss injections Wegovy and Mounjaro, but it is restricted to those having a high Body Mass Index (BMI) and at least one weight-related comorbidity (such as hypertension or cardiovascular disease).
An estimated 2.5 million people are taking it privately.
