Fat-burning supplements are one of the most-marketed and least-effective fitness categories. Most contain caffeine (genuine but modest effect), green tea extract (very weak effect), and ineffective fillers marketed as breakthrough ingredients.
What actually works for fat loss
Calorie deficit through diet (the 80% rule). Strength training to preserve muscle. Adequate protein. Adequate sleep. Walking 8-10k steps daily. None of which is a supplement.
Save the £40-60/month spend on fat burners. Invest in good food, decent training shoes, or therapy if stress eating is the actual issue.