Fat burner supplements are a multi-billion dollar industry built largely on exaggerated claims and wishful thinking. Most fat burners provide modest benefits at best - none produce the dramatic fat loss depicted in marketing without accompanying diet and exercise. However, some ingredients have legitimate evidence for modest fat loss support.
Evidence-based fat loss ingredients: Caffeine is the most effective legal thermogenic, increasing metabolic rate by 3-11% and mobilising fatty acids for use as fuel. Green tea extract (EGCG) works synergistically with caffeine to modestly increase fat oxidation. Capsaicin (from chilli) temporarily increases thermogenesis. L-carnitine may improve fat transport into mitochondria for energy, though evidence is mixed. These ingredients provide small incremental benefits (perhaps 50-100 extra calories burned per day) - meaningful over time but not dramatic on their own.
Ingredients to avoid: DNP (dinitrophenol) is illegal and has caused deaths - refuse any product containing it. Synephrine (bitter orange) at high doses carries cardiovascular risks. ECA stacks (ephedrine-caffeine-aspirin) are prescription-only in Australia for good reason. Proprietary blends that don't disclose individual ingredient doses should be avoided as there's no way to assess safety or efficacy. The most effective fat burning supplement stack: a well-controlled diet, consistent training, and adequate sleep. These produce the 80% of results that supplements can only marginally support.