Black, white and green pepper are the same fruit of one vine, Piper nigrum, picked and processed at different stages. Black pepper is picked unripe, dipped briefly in hot water and dried until the skin darkens and wrinkles. White pepper is the seed of the ripe fruit, usually with the flesh removed by soaking for about a week. Despite the name, it is not closely related to chili peppers, which belong to the genus Capsicum. Its heat comes from piperine, not capsaicin, and piperine makes up roughly 4 to 6% of pepper by weight.
The peppery smell comes from other compounds. In 2008, scientists tracing the pepper note in Shiraz wine found rotundone, which is present in black and white peppercorns at about 10,000 times the level in very peppery wine. About 1 in 5 tasters could not smell it at all, even at the highest level tested.
A teaspoon of ground black pepper (2.3 g) has 6 calories and 13% of the daily value of manganese, so it flavors food more than it feeds you. Most research tests piperine capsules or pepper oil instead of the kitchen spice, and only a few of the studies below fed people pepper.
Health benefits of black pepper
The top findings from 20 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★Lower fasting blood sugar, with curcuminCurcumin supplements with added piperine, the compound in pepper, lowered fasting blood sugar by 5.89 mg/dL across 15 trials, but not HbA1c. Piperine was always taken with curcumin.
- ★★Faster swallowing reflex after stroke, from the smellIn 105 older nursing home residents after a stroke, one minute of inhaling black pepper oil shortened the delay of the swallowing reflex. This was the smell of an oil, not eating pepper.
- ★Better absorption of carotenoids and curcuminBlack pepper plus an oil emulsion on a raw salad raised blood carotenoids 6.1-fold over 10 hours, compared with salad alone. Isolated piperine, taken with curcumin, raised curcumin absorption by 2,000% in healthy volunteers.
- ★Lower blood sugar after a starchy meal1 g of black pepper in a starchy breakfast lowered blood sugar after the meal in 20 healthy adults. Pepper also lowered hunger and raised fullness.
- ★Higher blood levels of some medicines20 mg of piperine, isolated from pepper, raised blood levels of propranolol and theophylline in healthy volunteers. A single 20 mg dose also raised levels of the epilepsy drug phenytoin.
All 20 studies, strongest evidence first
Breathing in black pepper oil for 1 minute shortened the delay of the swallowing reflex in older people after a stroke
Randomized trial in 105 people living in Japanese nursing homes after a stroke. One minute of inhaling black pepper oil shortened the delay compared with lavender oil and with plain water, and a 1-month course also improved it compared with before the study. This was the smell of an oil, not eating pepper, and it measured swallowing reflexes, not pneumonia.
Curcumin supplements with added piperine lowered fasting blood sugar by 5.89 mg/dL in a meta-analysis of 15 trials, but not HbA1c
Meta-analysis of 15 randomized trials (1,020 adults) of curcumin plus piperine. HbA1c, a 3-month blood sugar marker, fasting insulin and insulin resistance did not change significantly, and the authors rate the certainty of the evidence as low to moderate. Piperine was always given together with curcumin, so these trials cannot show what piperine does on its own.
Black pepper plus an oil emulsion on a raw vegetable salad raised carotenoids in the blood 6.1-fold over 10 hours compared with salad alone
Randomized crossover trial in healthy young adults, who ate the same salad plain, with black pepper, with a canola oil emulsion, or with both. The combination beat pepper alone by 2.1 times and the oil emulsion alone by 3.0 times, so pepper was only part of the effect. The rise was larger in women than in men, and the emulsion was a special preparation, not salad dressing.
1 g of black pepper in a starchy breakfast lowered blood sugar after the meal in healthy adults
Randomized crossover trial in 20 healthy adults, who ate four meals with 50 g of carbohydrate: plain, with 1 g of black pepper, with 1 g of turmeric, or with both. Meals with pepper also lowered hunger and raised fullness, with no change in stomach comfort. Each person was tested on a single meal, and the pepper-only meal scored lower for taste than the plain one.
Adding black pepper to turmeric for 21 days did not lower pain ratings more than turmeric alone in 30 adults with chronic pain
Randomized crossover trial in adults aged 40 and older with moderate pain (4 to 7 on a 10-point scale), using turmeric in cooking amounts (300 mg, 1 g or 3 g) with or without black pepper. Pain ratings fell over the 3 weeks in every group, and the abstract describes no placebo group. One author receives an honorarium from the McCormick Science Institute; the funders had no role in the study.
A capsule of 2 g of black pepper powder did not improve attention, energy or fatigue in 40 young adults with low energy
Placebo-controlled trial of capsules holding black pepper (2.0 g, a little less than a level teaspoon of ground pepper), rosemary (1.7 g) or rice flour. People wore a nose clip so smell played no part. Black pepper changed none of the attention, motivation or mood measures, while rosemary showed only small, brief effects at some time points.
Smelling black pepper oil for 1 minute before meals increased oral intake in 5 of 8 children who relied on tube feeding
Uncontrolled study of 10 children aged 19 to 97 months with severe neurological disorders on long-term tube feeding. Eight continued for 3 months, and 5 of them ate more by mouth, but none could stop tube feeding completely. For 3 the oil did not help, and 2 children stopped early because of cough or because the family could not bear the odor. This was the smell of an oil, not eating pepper.
Puffing black pepper vapor reduced cigarette craving in 48 smokers during a 3-hour session without smoking
Randomized trial in which smokers, after a night without cigarettes, inhaled vapor from black pepper essential oil, a mint/menthol vapor or an empty cartridge. Craving was lower with pepper than with either control, and negative mood and anxiety symptoms eased compared with the empty cartridge. It tested the oil in the airways, not eating pepper.
Piperine added to thickened drinks cut unsafe swallows by 34 to 57% in 40 people with swallowing problems
Videofluoroscopy study in 40 patients with oropharyngeal dysphagia, randomized to drinks with 150 µM or 1 mM of isolated piperine and compared with their own plain drinks. The lower dose shortened the time for the airway to close from 0.366 to 0.270 seconds. This was pure piperine in a clinic test, not pepper on food, and the authors think it works by stimulating nerves in the throat.
20 mg of piperine taken with 2 g of curcumin raised curcumin absorption by 2,000% in healthy volunteers
Absorption study in rats and healthy volunteers. On its own, 2 g of curcumin gave undetectable or very low blood levels in people, while with piperine levels were much higher during the first hour. In rats the rise was 154%. It tested isolated piperine with a curcumin supplement, not pepper with turmeric in food, and it measured absorption, not health benefits.
20 mg of piperine a day for 7 days raised blood levels of the drugs propranolol and theophylline in healthy volunteers
Crossover study with 6 people per drug, who took a single dose of propranolol (40 mg) or theophylline (150 mg) alone or together with isolated piperine. Peak and total drug levels were higher with piperine, and theophylline stayed in the body longer. It is one reason piperine supplements matter for people who take medicines.
A single 20 mg dose of piperine raised blood levels of the epilepsy drug phenytoin in patients taking it
Study in 20 patients with uncontrolled epilepsy, in two groups of 10 taking 150 or 200 mg of phenytoin twice a day. Each person was measured on a day without piperine and on a day with it. Piperine raised both the peak level and the total drug exposure in both groups.
5 mg of piperine with 120 mg of coenzyme Q10 for 21 days raised CoQ10 blood levels about 30% more than CoQ10 with placebo
Double-blind study in healthy men, using an extract that was at least 98% pure piperine. The gain was statistically significant only after 21 days; a single dose and 14 days gave smaller rises that were not significant. It tested a supplement of CoQ10, a compound the body makes, not food.
20 mg of piperine with 250 mg of resveratrol raised blood flow in the front of the brain during tasks but did not change thinking scores
Randomized, double-blind, placebo-controlled crossover trial in 23 adults. Compared with placebo and with resveratrol alone, the combination increased blood flow in the frontal cortex, while cognition, mood and blood pressure were unchanged. Blood levels of resveratrol did not differ, so piperine did not raise its absorption here.
Adding 2 mg of piperine to 3 g of turmeric a day for 12 weeks lowered a marker of oxidative damage and ferritin more than turmeric alone in people on hemodialysis
Randomized, double-blind trial comparing 3 g of turmeric a day with the same turmeric plus 2 mg of piperine. The oxidative marker (MDA) and ferritin fell only with piperine, while catalase, glutathione reductase and the inflammation marker hs-CRP did not change. This is one of few trials that tests what piperine adds to turmeric.
A curcumin and piperine preparation did not change blood levels of three test drugs in 8 healthy volunteers
Randomized placebo-controlled crossover study. People took 4 g of curcuminoids with 24 mg of piperine four times over 2 days before a test dose of midazolam, flurbiprofen or paracetamol (acetaminophen). The authors conclude that short-term use is unlikely to cause a clinically significant interaction, which differs from the piperine trials above.
Piperine blocked the drug transporter P-glycoprotein and the enzyme CYP3A4 in human gut cells and liver tissue
Lab study using Caco-2 gut cell layers and human liver microsomes. Piperine reduced the transport of digoxin and cyclosporine A (IC50 15.5 and 74.1 µM) and slowed CYP3A4 breakdown of verapamil. The authors say dietary piperine could change blood levels of drugs handled by these proteins, especially those taken by mouth.
In mice, piperine raised blood levels of the green tea compound EGCG 1.3-fold
Mice were given EGCG (163.8 µmol/kg) with or without piperine (70.2 µmol/kg) by stomach tube. In small-intestine tissue, 100 µmol/L of piperine cut EGCG glucuronidation, a step that clears it, by 40%, and piperine also slowed gut transit. It is an animal result at doses given by tube.
Rats fed piperine for 8 weeks had higher activity of pancreatic digestive enzymes, including lipase, amylase and trypsin
Rats ate diets containing piperine (20 mg%) or other spice compounds. A single oral dose did not have the effect. The authors suggest this may be part of why spices are thought to help digestion.
In rats on a high-fat diet, black pepper and piperine lowered markers of oxidative damage and kept antioxidant enzymes near normal
Thirty rats ate a high-fat diet for 10 weeks, with black pepper (0.25 or 0.5 g/kg of body weight) or piperine (0.02 g/kg) added. Both lowered markers of fat oxidation in the liver, heart, kidney, intestine and aorta. These are animal doses scaled to body weight, not a human meal.
Who should be careful with black pepper
Most people can eat black pepper freely. Take a little care if one of these applies:
- Medicines and piperine supplements. In trials, 20 mg of isolated piperine raised blood levels of drugs such as phenytoin, propranolol and theophylline. A review by Germany’s federal risk institute (BfR) advises people who take medicines to ask a doctor before using isolated piperine supplements. It is about concentrated doses taken at once, not pepper used as seasoning.
- Turmeric supplements with added piperine. The BfR warned in 2021 that adding piperine to curcumin supplements can push intake past the EFSA acceptable daily intake of 3 mg per kg of body weight, and that liver-damaging effects have been seen with boosted products, though some also held other ingredients. Check the label and the dose.
- Allergy. It is uncommon, but in a US patient registry of 616 people who reported an herb or spice allergy, black pepper was one of the five most reported. These were self-reported diagnoses.
How to choose, store and eat black pepper
- Black, white or green: the same fruit processed differently. White is the seed with the flesh removed, and green is picked unripe and kept green. No study here compares them.
- With oil and vegetables: black pepper plus an oil emulsion raised blood carotenoids from a raw salad 6.1-fold, though pepper alone gave less than half of that.
- Late in cooking: cooking tests cited in a BfR review lost 4 to 12.5% of the piperine in one study and about 28 to 34% in another, so stir pepper in near the end.
Buy small amounts: ground pepper lost 12 to 30% of its piperine in 6 months at 4 °C in a test cited by the BfR review. In FDA testing for the 2017 update of its spice risk profile, 3 of 1,264 retail black pepper samples (0.24%) carried Salmonella, against 15 of 223 samples at import (6.7%), so retail pepper tested far cleaner than shipments at the border.
Sources
- Ziegenhagen R, Heimberg K, Lampen A, Hirsch-Ernst KI. Safety aspects of the use of isolated piperine ingested as a bolus. Foods. 2021.
- Curcumin in food supplements: acceptable daily intake may be exceeded. BfR Opinion No 040/2021. German Federal Institute for Risk Assessment. 2021.
- Liu EY, Lopez S, Bufford JL, Laidlaw TM, Baloh CH. Seeds, spices: not always so nice. A report on the Food Allergy Research & Education Patient Registry. J Allergy Clin Immunol Pract. 2026.
- Luo H, Li Z, Straight CR, et al. Black pepper and vegetable oil-based emulsion synergistically enhance carotenoid bioavailability of raw vegetables in humans. Food Chem. 2022.
- Risk profile: pathogens and filth in spices. US Food and Drug Administration. 2017 update.
- Black pepper. Wikipedia.
History of black pepper
Black pepper is a vine from South Asia, and India’s Malabar Coast has long been its most important source. The ancient port of Muziris on that coast traded pepper with Rome, Egypt, Mesopotamia, the Levant and Yemen.
Pepper reached ancient Egypt very early. Black peppercorns were placed in the nostrils of Ramesses II when he was mummified after his death in 1213 BCE. In Rome, pepper was a known but expensive seasoning, and Pliny the Elder priced black pepper, the cheapest kind, at four denarii a pound.
In the 5th century the Visigoth king Alaric demanded 3,000 pounds of pepper as part of the ransom of Rome. High prices and Venetian control of the trade pushed Portugal to look for a sea route to India, and Vasco da Gama reached it in 1498.
Pepper was a status symbol in medieval Scandinavia. When the Danish-Norwegian warship Gribshunden sank in the Baltic Sea in 1495, archaeologists found peppercorns together with saffron, ginger, clove and almond, spices carried for a political summit. Wikipedia counts more than 2,000 peppercorns from the wreck.
A popular story says pepper hid the taste of spoiled meat. Historians think that is very unlikely, because pepper was a luxury and people knew spoiled food made them ill. In the 16th century Europeans began calling the chilies of the New World “pepper” too, and the old phrase “peppercorn rent” still means a token payment.
Sources
- Black pepper. Wikipedia.
- Larsson M, Foley B. The king’s spice cabinet: plant remains from Gribshunden, a 15th century royal shipwreck in the Baltic Sea. PLoS One. 2023.
- Wood C, Siebert TE, Parker M, et al. From wine to pepper: rotundone, an obscure sesquiterpene, is a potent spicy aroma compound. J Agric Food Chem. 2008.
- Ziegenhagen R, Heimberg K, Lampen A, Hirsch-Ernst KI. Safety aspects of the use of isolated piperine ingested as a bolus. Foods. 2021.
Frequently asked questions about black pepper
Is black pepper good for you?
It is a good seasoning more than a health food. One teaspoon of ground black pepper (2.3 g) has 6 calories and 13% of the daily manganese, but you eat too little for much more. Of the 20 studies here, only 4 gave people pepper as food or powder, and the best-known results come from piperine capsules and pepper oil. For most people, pepper in cooking amounts is fine.
Does black pepper help you absorb turmeric?
Isolated piperine does raise curcumin levels, but food has barely been tested. In the classic trial, 20 mg of piperine with 2 g of curcumin raised curcumin absorption by 2,000%. In 30 adults using turmeric in cooking amounts, adding black pepper did not lower pain ratings more than turmeric alone. In people on hemodialysis, 2 mg of piperine added to 3 g of turmeric lowered a marker of oxidative damage more than turmeric alone.
How much black pepper is too much?
No study here sets an upper limit for pepper used as seasoning. The BfR estimated an average of 0.6 g a day for German men and 1.6 g a day at the 95th percentile. Its concern is isolated piperine supplements, which often hold 5 to 30 mg per daily dose. If you take medicines, ask before using them.
What is the difference between black and white pepper?
They are the same fruit, processed differently. Black pepper is picked unripe, briefly cooked in hot water and dried with its skin. White pepper is the seed of the ripe fruit with the flesh removed, usually by soaking for about a week. No study here compares their health effects.
Is black pepper the same as chili pepper?
No, they are different plants. Black pepper is the dried fruit of the vine Piper nigrum, while chilies belong to the genus Capsicum. Black pepper’s heat comes from piperine and a chili’s from capsaicin, and refined piperine is about 1% as hot as capsaicin by weight.
How many calories are in black pepper?
Very few. One teaspoon of ground black pepper (2.3 g) has 6 calories, 0.6 g of fiber and 0.2 g of protein. No study here tested weight loss with black pepper.
Does black pepper lower blood sugar?
It might lower it a little after a meal, but the evidence is thin. In 20 healthy adults, 1 g of black pepper in a starchy breakfast lowered blood sugar afterward compared with the plain meal. Curcumin plus piperine supplements lowered fasting blood sugar by 5.89 mg/dL in a meta-analysis of 15 trials but not HbA1c, and those trials cannot show what piperine adds. If you manage diabetes, keep to your care plan.
Can black pepper interact with medicines?
Isolated piperine can. In trials, 20 mg of piperine raised blood levels of phenytoin, propranolol and theophylline, and lab tests show it blocks P-glycoprotein and CYP3A4. A curcumin and piperine preparation with 24 mg of piperine changed none of three test drugs, so results differ. The BfR advises people on medicines to ask a doctor before using isolated piperine supplements, and no study here tested pepper on food.