Table 1. Clinical studies of the weight-loss effects of capsaicin.

Treatments	Year	Country	Study design	Subjects included	Baseline BMI	Sample size	Age (years)	Outcomes	Adverse events	Potential mechanism	Reference
Capsinoids (6 mg per day for 12 weeks)	2009	U.S.A.	Double-blind, randomized, placebo-controlled trial	Overweight individuals	30.6 ± 2.4	N=80	42 ± 8	Body weight decreased 0.92 kg; abdominal fat decreased 1.11%	None	Increase in fat oxidation and genetic polymorphisms	Snitker et al. [35]
Red pepper (capsaicin 10 g single meal)	1999	Canada	Prospective study	Healthy individuals	25.3 ± 4.7	N=23	25.8 ± 2.8	Decreased appetite	None	Increase in sympathetic nervous system activity	Yoshioka et al. [40]
Capsinoids (10 mg/kg per day for 4 weeks)	2007	Japan	Double-blind, randomized, placebo-controlled trial	Men and postmenopausal women	>23	N=48	30–65	Body weight tended to decrease during the 2- to 4-week period	None	Increased VO2, energy expenditure, and fat oxidation	Inoue et al. [37]
Capsaicin (135 mg per day for 3 months)	2003	Netherlands	Randomized double-blind placebo-controlled study	Moderately overweight subjects	29.3 ± 2.5	N=140	18–60	Significant increase in resting energy expenditure	None	More sustained fat oxidation	Lejeune et al. [36]
Capsinoids (9 mg per day for 8 weeks)	2016	Japan	Randomized double-blind placebo-controlled study	College students	21.4 ± 1.8	N=20	20.7 ± 1.2	Increased brown adipose tissue (BAT) density	None	Increased BAT activity	Nirengi et al. [43]