Obesity is well known to be an important comorbidity of psoriasis. It gives rise to higher risk of psoriatic arthritis, more severe disease and also poorer response to biologics. Weight loss can lead to reduction in psoriasis severity. Previous studies had demonstrated the efficacy of older glucagon-like peptide-1 receptor agonist (GLP1 RA) on improvement of psoriatic disease activity. Effective weight loss has been achieved by newer GLP1 RA.7 It is also known to reduce cardiovascular outcomes in patient without diabetes. Trials on the effect of semaglutide on psoriasis has not been performed except case reports. Semaglutide is an injectable prescription medicine that may help adults and children aged 12 years and older with obesity or some adults with excess weight (overweight) who also have weight-related medical problem to help them lose weight. It contains a GLP1 RA indicated as an adjunct to diet and exercise to improve glycemic control. It has potential anti-inflammatory effects on top of weight reduction, that may lead to improvement in psoriatic disease activity. This is an open-label, single-armed, prospective pilot trial on obese, psoriasis patients. The investigators aim to recruit 14 patients. Patients will be maintained on standard care for their psoriasis. Add-on treatment with semaglutide of up to 2.0mg per week will be administered to the intervention arm in addition to lifestyle intervention. Treatment with previous systemic immunosuppressants is allowed. The maximum study duration for a single subject in the study will be approximately 36 weeks, 4 weeks of screening, 24-week treatment period, and a 12-week safety follow up period after the last study dose of semaglutide at week 24.