Table 1.

An overview of human studies on the effects of black pepper (Piper nigrum) and its active ingredient, piperine, against diverse metabolic complications.

Author, Year	Country	Study Population	Intervention	Comparator (If Any)	Main Findings
Gregerse et al., 2013 [137]	Denmark	Individuals subjected to diet-induced thermogenesis (n = 22), with an average age of 25 years	Brunch meal with black pepper at 1.3 g, ginger (20 g), horseradish (8.3 g), and mustard (21 g) for 4 h	Placebo	Did not affect diet-induced thermogenesis; measurements of appetite and energy balance were also not affected
O’Connor et al., 2013 [138]	United States	Overweight women (n = 17), with an average age between 52–69 years	Black pepper at 1.5 g for 24 h	Placebo	Did not affect energy expenditure or respiratory quotient, including levels of glucose, insulin, catecholamines, and gut peptides
Rondanelli et al., 2013 [91]	Italy	Overweight individuals (n = 41), with an average age between 25 and 45 years	Two capsules per day, mainly containing Camellia sinensis decaffeinated dried extract (150 mg/cpr), microencapsulated oleoresin of Capsicum annum (7.5 mg/cpr), and piper nigrum dry extract, (3 mg/cpr) for 8 weeks	Placebo	Reduced obesity-related inflammatory metabolic dysfunction by ameliorating insulin resistance, improving the leptin/adiponectin ratio, respiratory quotient, and low-density lipoprotein (LDL) cholesterol levels
Hobbs et al., 2014 [139]	United States	Individuals with hypercholesterolemia (n = 19), with an average age between 18 and 80 years	Softgel that contained different active ingredients (such as bioflavonoids, vitamins, omega-3 fatty acids, and black pepper) for 30 days	Placebo	Reduced total cholesterol, low-density lipopolysaccharide, and triglyceride levels
Rofes et al., 2014 [140]	Spain	Individuals with oropharyngeal dysphagia (n = 40), with an average age between 74 and 78 years	Piperine at 1 mM or 150 μM during oropharyngeal swallow response	None	Alleviated oropharyngeal dysphagia by improving swallowing, with the time of laryngeal vestibule closure shortened at both concentrations
McCrea et al., 2015 [141]	United States	Overweight individuals given a high-fat meal (1000 kcal, 45 g fat) (n = 20), with an average age between 30 and 36 years	Capsule with a combination of spices (black pepper, cinnamon, cloves, garlic, ginger, oregano, paprika, rosemary, and turmeric) at 14.5 g for up to 210 min	Placebo	Reduced triglyceride levels, but did not have effects on glucose or insulin levels
Panahi et al., 2015 [142]	Iran	Individuals with metabolic syndrome (n = 50), with an average age between 36 and 53 years	Curcuminoids at 1 g, co-administered with piperine at 10 mg daily for 8 weeks	Placebo	Improved oxidative and inflammatory status by enhancing serum levels of superoxide dismutase (SOD) while reducing that of malonaldehyde (MDA), together with C-reactive protein
Gilardini et al., 2016 [143]	Italy	Obese females (n = 20), with an average age between 40 and 60 years	Formulation containing Camellia sinensis, titrated as > 60% polyphenols and > 40% in epigallocatechin-O-gallate, complexed with soy distearoylphosphatidylcholine and pure piperine (15 mg/dose) for 3 months	Placebo	Reduced body weight and fat mass
Zanzer et al., 2018 [144]	Sweden	Individuals receiving a meal rich in carbohydrates (n = 16), with an average age between 25 and 27 years	Black pepper-based beverage at 220 mL (20 mg gallic acid equivalent) up to 180 min	Placebo	Did not affect metabolic status. Also, the was no observed effects in the gastrointestinal well-being. However, there was suppression of hunger and improved satiety.
Mahmoudpour et al., 2019 [145]	Iran	Individuals with functional bloating (n = 36), with an average age between 20 and 50 years	Formulation containing Trachyspermum ammi (L.) Sprague seed, Zingiber officinale Roscoe. Rhizome, and Piper nigrum L. berry at 500 mg three times a day for 2 weeks	Placebo	Improved bloating status, including eructation, defecation, and borborygmus, better than dimethicone
Heidari-Beni et al., 2020 [146]	Iran	Individuals with chronic knee osteoarthritis (n = 30), with an average age between 35 and 75 years	Herbal formulation containing curcumin (300 mg), gingerols (7.5 mg), and piperine (3.75 mg), taken twice a day for 4 weeks	Naproxen at 250 mg	Potentially protected against chronic knee osteoporosis by reducing levels of prostaglandin E2
Oh et al., 2020 [147]	United States	Overweight or obese subjects (n = 12) given a high-fat meal (1000 kcal) (n = 20), with an average age between 40 and 65 years	Combination of spices (basil, bay leaf, black pepper, cinnamon, coriander, cumin, ginger, oregano, parsley, red pepper, rosemary, thyme, and turmeric) at 2 g for up to 4 h	Placebo	Alleviated high-fat-meal-induced postprandial interleukin (IL)-1β secretion
Pastor et al., 2020 [148]	Argentina	Individuals with metabolic syndrome (n = 22), with an average age between 63 and 73 years	Formulation containing resveratrol at 50 mg, piperine at 5 mg, and alpha tocopherol a 25 mg, with habitual treatment for 3 months	Placebo	Ameliorated inflammation by reducing levels of ferritin, ultrasensitive C-reactive protein, and oxygen consumption
Lindheimer et al., 2023 [149]	United States	Young adults with low energy (n = 40), with an average age between 18 and 34 years	Black pepper capsules twice a day at 0.504 g for 2 days	Rosemary at 0.425 g	Did not affect energy levels or fatigue feelings; however, rosemary induced a reduction in false alarm errors and mental fatigue at different time periods