Capsaicin, the active compound in chili peppers, has garnered interest in the bodybuilding and fitness communities primarily for its potential metabolic and thermogenic effects. Scientific studies indicate that capsaicin can modestly increase energy expenditure and fat oxidation, which could theoretically support weight management and body composition goals in athletes and bodybuilders. Research has shown that capsaicin activates transient receptor potential vanilloid 1 (TRPV1) receptors, leading to increased catecholamine secretion (e.g., adrenaline), which in turn may elevate metabolic rate and promote lipolysis (fat breakdown).

However, the evidence supporting capsaicin’s direct impact on muscle growth, strength, or athletic performance is limited. Most studies focus on its role in weight loss or energy metabolism, with only a few small-scale human trials and animal studies suggesting potential benefits for fat mass reduction. Some evidence also points to capsaicin’s anti-inflammatory and analgesic properties, which could theoretically aid in recovery, but these effects are more relevant to topical use rather than oral supplementation. Overall, while there is preliminary scientific support for capsaicin’s use in metabolic enhancement, its direct effects on bodybuilding-specific outcomes (such as muscle hypertrophy or strength) are not well established.

In summary, capsaicin is used in bodybuilding mainly for its potential to increase metabolism and support fat loss, but the current scientific evidence is moderate and does not strongly support significant benefits for muscle building or performance.