Psoriasis is an immune-mediated inflammatory condition affecting the skin, nails, and joints. Turmeric contains curcumin, a yellow-pigmented polyphenol with anti-inflammatory properties. Several diseases, including psoriasis, have been treated with turmeric in Asian countries since ancient times as a topical application and dietary supplement. This phase 3, single-dose, randomised, double-blind, placebo-controlled clinical trial evaluated the efficacy of curcumin as a complementary therapy for the treatment of mild-to-moderate psoriasis. This study used Meriva, a curcumin supplement that contains lecithin to boost the bioavailability and absorption of curcumin. The study assessed the effect of curcumin supplementation on inflammatory cytokine secretion by the immune cells. For 12 weeks, sixty-three patients with mild-to-moderate psoriasis were randomly assigned to either receive 2 grams of oral curcumin supplement, Meriva, along with topical steroid cream (Methylprednisolone aceponate 0.1%), or topical steroid cream alone. Treatment with 2 grams of oral curcumin supplementation and topical steroid cream application for 12 weeks significantly reduced the secretion of inflammatory cytokine, IL-22, in the serum of psoriatic patients. Additionally, the treatment reduced the proliferation of outer skin cells. Further robust studies are required to analyse the beneficial effects of curcumin on other pathogenic pathways of psoriasis. The study can help healthcare professionals learn more about the benefits of curcumin supplements for treating psoriasis in conjunction with conventional medicine.