Black Pepper

Piper nigrum L. belongs to Piperaceae, the pepper family, and was first published by Linnaeus in Species Plantarum in 1753, according to Kew’s Plants of the World Online (POWO). Where it is native is being rethought. Kew’s descriptive account says black pepper is native to the Western Ghats of Kerala in India, where it grows wild in the mountains, but POWO’s distribution data now list its native range as Sri Lanka alone, with India among dozens of regions where it is introduced. That shift matches new genetic work. Metschina and colleagues (American Journal of Botany 2026) found that cultivated pepper sits within a group of species found only in Sri Lanka, more closely related to them than to two Indian species previously proposed as its parents. They suggested pepper arose in Sri Lanka and was carried early to the Malabar Coast of India and then to Sumatra, while acknowledging that their limited Indian sampling weakens the conclusion. They also found that most cultivated varieties are autotetraploid, carrying four sets of chromosomes from a single ancestral species rather than being hybrids, with some diploid varieties still grown. Today pepper is cultivated throughout the tropics, and Kew names Vietnam, Indonesia, Brazil, and India as the major producers.

Kew describes a climber that reaches 10 m or more, forming a column of side shoots held to its support by short adventitious roots that grow from the stems; the Flora of China description quoted by World Flora Online notes clearly swollen, rooting nodes. The leaves are almond-shaped and taper to a point, dark green and shiny above and paler below, and alternate along the stem. Tiny whitish to yellow-green flowers, 50 to 150 of them, crowd along slender stalks called spikes; the Flora of China account describes the flowers as a mix of bisexual and single-sex ones. Each spike ripens 50 to 60 round, berry-like fruits up to 6 mm across, botanically drupes, each with a single seed; they are green at first and turn red as they ripen (Kew). The color of a peppercorn depends on harvest and processing. Kew explains that fruits picked green and immature become green pepper; fruits that are fully grown but still green and shiny are dried into black pepper (the Flora of China notes that unripe fruits dry black); and slightly riper fruits are soaked to strip away the fleshy outer layer, leaving white pepper. Pink peppercorns come from an unrelated tree, Schinus terebinthifolia, in the cashew family, and Sichuan pepper from Zanthoxylum species in the citrus family. Relatives within the genus include long pepper (Piper longum), native from Assam to Burma, and kava (Piper methysticum).

Piperine (1-piperoylpiperidine) is the main pungent compound in both black and white pepper (Singletary). Estimates of how much pepper contains vary: Sabinsa, a supplier of piperine extracts, cites 3–9%, and Singletary assumed 6% of dry weight for his calculations. Light converts some piperine into three related shapes of the same molecule, isopiperine, chavicine, and isochavicine; in four commercial ground black peppers, Kozukue and colleagues (Journal of Agricultural and Food Chemistry 2007) found these isomers only in small amounts relative to piperine. Friedman and colleagues (2008) measured pungent amides in 20 commercial products and found levels ranging widely, highest in green peppercorns and lowest in red, with piperine and its isomers making up on average 84% of the total and compounds such as piperanine, piperettine, and piperyline the rest. The aroma comes from an essential oil. Singletary lists α- and β-pinene, limonene, and β-caryophyllene among its components, and one 2023 analysis of pepper fruit oil (Weluwanarak and colleagues, Plants) found sabinene (24%), limonene (24%), β-caryophyllene (19%), and α-pinene (11%) as major constituents. Pepper also contains fiber, eugenol, and minerals. Quality problems are ancient: Pliny reported pepper adulterated with juniper berries.

Pepper’s medical history begins in South Asia. Singletary notes that its medicinal use was documented in ancient Sanskrit literature, that it became one of the most commonly used herbs in Ayurvedic medicine, considered for digestive disorders among other complaints, and that traditional Chinese medicine used it for epilepsy. The American Herbal Products Association’s identity compendium gives its Ayurvedic name as maricha. Its most famous Ayurvedic role is in trikatu, “the three pungents,” a mixture of black pepper, long pepper, and ginger. In a 1992 review, Johri and Zutshi (Journal of Ethnopharmacology) described trikatu as prescribed routinely for a variety of diseases as part of multi-ingredient prescriptions and suggested that its traditional inclusion might be explained by its ability to boost the absorption of other medicines, an idea that helped launch modern research on piperine. A 2019 systematic review by Takooree and colleagues (Critical Reviews in Food Science and Nutrition) found that India had the most recorded traditional uses, chiefly for menstrual and ear, nose, and throat complaints in people and digestive problems in livestock, with the fruit usually taken as a powder, pill, or paste. None of these traditional uses has been confirmed in clinical trials.

Pepper drew the Roman world east. In his Natural History, written in the first century, Pliny the Elder listed long pepper at 15 denarii a pound, white pepper at 7, and black at 4, and marveled that a substance with no sweetness or beauty, only pungency, was imported all the way from India and bought by weight as if it were gold or silver. His botany was muddled: he thought long pepper pods ripened into white pepper, an error his nineteenth-century translators flagged. Trade with South India is documented in a remarkable papyrus now in Vienna, dated to the middle of the second century. One side preserves part of a loan contract for a voyage from Alexandria to the South Indian port of Muziris; the other values three-quarters of the cargo of a ship called the Hermapollon at 1,154 talents and 2,852 drachmas of silver, in D. Rathbone’s translation. The surviving lines cover Gangetic nard and ivory, and historian Federico De Romanis argues that the missing portion held pepper and malabathron. Centuries later, pepper still counted as treasure. The historian Zosimus records that when Alaric’s Goths besieged the city, Rome agreed to pay 5,000 pounds of gold, 30,000 of silver, 4,000 silk robes, 3,000 scarlet fleeces, and 3,000 pounds of pepper.

In medieval Europe, Singletary notes, pepper was used both to season food and to mask the flavor of salted, cured meat. Its value survives in the English legal phrase “peppercorn rent,” which Merriam-Webster defines as a rent once often paid in a set amount of black peppercorns, and now a merely nominal rent. The hunt for spices drove European exploration: the Naturalis Biodiversity Center’s economic botany guide notes that Columbus was sent in 1492 largely in search of the spice islands, that Vasco da Gama sailed around Africa in 1498 and reached the source of pepper, and that the Portuguese held the trade monopoly until the seventeenth century, when the Dutch captured much of it and set up plantations on Java and Sumatra while the British did the same in Malaysia. Pepper oil distilled from the fruit later entered perfumery. The modern chapter began with pharmacology: by 1987 Bano and colleagues were testing piperine’s effect on phenytoin levels in volunteers, and in 1996 the supplement company Sabinsa received a US patent on piperine to increase the bioavailability of nutritional compounds, the basis of its BioPerine extract, standardized to at least 95% piperine.

Pepper’s bite is a nerve signal. McNamara and colleagues (British Journal of Pharmacology 2005) showed that piperine activates human TRPV1, the ion channel on pain-sensing nerves that responds to heat and to capsaicin from chili peppers. Piperine was far less potent than capsaicin (it needed a concentration of about 38 micromolar for half its maximum effect, against 0.29 for capsaicin), but at full strength it produced roughly twice the response, and it desensitized the receptor more quickly. That shared receptor explains why pepper and chili both feel hot, even though the plants are unrelated. In the stomach, Myers and colleagues (American Journal of Gastroenterology 1987) found that 1.5 g of black pepper increased acid and pepsin secretion in healthy volunteers. Animal studies reviewed by Srinivasan (Critical Reviews in Food Science and Nutrition 2007) report that piperine stimulates digestive enzymes and shortens food transit time, but a 16-person pilot study found that 1.5 g of black pepper, if anything, slowed transit through the small intestine, from 90 to 122 minutes on average, a change that was not statistically significant (Vazquez-Olivencia and colleagues 1992). β-caryophyllene from the essential oil binds the CB2 cannabinoid receptor and reduced inflammation in mice (Gertsch and colleagues, PNAS 2008), though no one has shown that the small amounts in pepper do the same.

Piperine’s best-studied action is on the systems the body uses to clear foreign substances. Shoba and colleagues described it as a known inhibitor of glucuronidation, the process by which the liver and intestinal wall attach a sugar acid to compounds such as curcumin so they can be excreted. Srinivasan’s review adds that piperine strongly inhibits the enzymes aryl hydrocarbon hydroxylase and UDP-glucuronyl transferase in the liver and gut, and that part of its effect may come from changes to the intestinal lining that increase absorption. Bhardwaj and colleagues (Journal of Pharmacology and Experimental Therapeutics 2002) then showed in human cells and liver tissue that piperine inhibits both P-glycoprotein, a pump that pushes many drugs back out of gut cells, and CYP3A4, a major drug-metabolizing enzyme in the liver and gut. Piperine blocked P-glycoprotein transport of digoxin and cyclosporine and slowed CYP3A4 metabolism of the heart drug verapamil. Because both proteins sit in the gut wall and liver, where swallowed drugs are filtered before reaching the bloodstream, the authors concluded that dietary piperine could raise blood levels of drugs handled by them, especially drugs taken by mouth.

How much this matters in people depends on the drug, the dose, and the timing. Several small human studies, described under interactions, found clear rises in drug levels with 20 mg of piperine a day. But Volak and colleagues (British Journal of Clinical Pharmacology 2013) gave eight volunteers a curcumin product containing 24 mg of piperine four times over two days and found no meaningful change in the handling of midazolam, flurbiprofen, or paracetamol (acetaminophen), probe drugs for CYP3A, CYP2C9, and the liver’s conjugation enzymes; unconjugated piperine in the blood stayed below the level their test could detect. A 2024 computer model by Lin and colleagues predicted that 20 mg a day for a week would raise exposure to six CYP3A4 drugs by 31–59%, simvastatin the most, but that is a simulation, not a measurement. The smell-based effects work through other routes. Ebihara and colleagues found that black pepper oil increased blood flow in the insular and orbitofrontal cortex, brain areas involved in swallowing, and raised blood levels of substance P, a nerve messenger, while Rose and Behm attributed reduced cigarette craving to sensations in the chest and airways that mimic smoking.

Food is black pepper’s main use, and Kew notes that it is also used in traditional medicine, particularly for digestive ailments. The clinical evidence for digestive benefits is slim. Singletary graded pepper’s effects on digestive function as emerging and suggestive, based mainly on rodent studies plus small human experiments, and noted that the animal results are not always consistent. The human studies are physiology experiments rather than treatment trials: pepper increased stomach acid and pepsin in volunteers but also caused small bleeds in the stomach lining, and it did not speed transit through the gut. There are no trials showing that black pepper treats indigestion, bloating, or any other digestive condition. For those complaints, herbs such as ginger and peppermint have much more research behind them. Pepper’s other traditional reputations, from colds and fevers to menstrual complaints, have not been tested in modern trials.

Raising curcumin levels is the use that sells the most pepper extract. Shoba and colleagues (Planta Medica 1998) first showed the effect in rats, where 20 mg/kg of piperine raised curcumin bioavailability by 154%, and then in healthy volunteers, where 2 g of curcumin alone produced blood levels that were either undetectable or very low, and adding 20 mg of piperine produced much higher levels from 15 minutes to one hour after the dose and a 2000% increase in bioavailability, with no adverse effects reported. Turmeric capsules with black pepper extract are now widely sold as a combination product. Mimica and colleagues (Pharmaceuticals 2022) analyzed 165 randomized trials of oral curcumin and found that 64% used some method to improve absorption; adding piperine was the most common (23%), ahead of phospholipid, nanomicelle, and other formulations. They also found that very few trials compared products, and only nine measured bioavailability. Any benefits reported in turmeric-plus-pepper trials, such as for joint pain, belong to those specific products and to curcumin; they are not evidence that black pepper treats those conditions, and the extra contribution of piperine to health outcomes has rarely been tested directly. Higher absorption may also raise risks, a point covered in the turmeric monograph.

The same enhancing effect has been explored for other nutrients and drugs. Singletary summarizes studies reporting higher blood levels of beta-carotene and coenzyme Q10 supplements with piperine, and of a green tea catechin in mice. Some researchers have proposed exploiting the effect deliberately: Bano and colleagues (European Journal of Clinical Pharmacology 1991) suggested that the higher levels of propranolol and theophylline they observed could be exploited for better therapeutic control, and Kasibhatta and Naidu (Drugs in R&D 2007) suggested the same for nevirapine. These remain research ideas. Deliberately using piperine to change the dose of a prescription medicine, without a prescriber adjusting and monitoring it, is unsafe, because the size of the effect varies between drugs and between people.

Swallowing problems in older adults have one notable trial. Ebihara and colleagues (Journal of the American Geriatrics Society 2006) studied 105 residents of Japanese nursing homes, most disabled by strokes, in a one-month randomized study. A single minute of breathing in black pepper oil through the nose shortened the delay before the swallowing reflex fired, compared with lavender oil or distilled water. Over a month of use, swallowing latency improved, residents swallowed more often during exposure, and blood levels of substance P rose. A delayed swallowing reflex is a risk factor for aspiration pneumonia, which is why the work drew interest, but the trial measured reflexes and brain blood flow, not pneumonia rates, and the related studies we found come largely from the same Japanese group. A smaller study involving the group found that brief exposure to black pepper or lavender oil steadied postural sway with the eyes closed in 17 older adults (Freeman and colleagues, Gait and Posture 2009). Anyone with swallowing difficulty needs assessment by a doctor or speech and language therapist rather than aromatherapy alone.

Cigarette craving is the other human finding. Rose and Behm (Drug and Alcohol Dependence 1994) had 48 smokers abstain overnight and then spend three hours puffing on a cigarette-like device that delivered vapor from black pepper essential oil, a mint and menthol vapor, or nothing. Craving was significantly lower with pepper than with either comparison, and negative mood and physical symptoms of anxiety were eased compared with the empty device; smokers also felt stronger sensations in the chest. It was a single laboratory session and did not test whether anyone quit smoking. Beyond these studies, Singletary rated proposed benefits for weight, the nervous system, mood, the depigmenting skin condition vitiligo, inflammation, infection, and cancer as preliminary and inconclusive, because they rest on cell and animal research.

Black pepper is sold as whole black, white, green, and red peppercorns, as ground pepper, and as an essential oil distilled from the fruit, which is used in perfumery. Supplements use piperine extracts: Sabinsa’s BioPerine, for example, is standardized to at least 95% piperine and is marketed with self-affirmed GRAS status, meaning the company itself, rather than a US Food and Drug Administration review, concluded it was safe. Doses differ enormously across these forms. Singletary estimated typical consumption at about 0.3 g of pepper a day in India, similar to US estimates, while human experiments used about 1.5 g. Piperine in human studies has usually been given at 5 to 20 mg, and assuming pepper is 6% piperine, he calculated that this equals the piperine in roughly 83 to 333 mg of black pepper. In the key studies, Shoba used 20 mg of piperine with 2 g of curcumin, and Volak used 24 mg with 4 g of curcuminoids. Turmeric-and-pepper products vary in how much of each they contain, so the label matters more than the name.

In the kitchen, quality and storage matter. Light gradually converts piperine into its isomers (Kozukue and colleagues 2007), one reason to keep pepper in a closed container away from light. Pepper is a raw agricultural product and can carry bacteria. From July 2009 to April 2010, 272 people in 44 US states and the District of Columbia were infected with Salmonella Montevideo traced to imported black and red pepper that had been added to salami after the step meant to kill germs; 52 of 203 people with information available were hospitalized, and no deaths were reported (Centers for Disease Control and Prevention, MMWR 2010). The CDC concluded that the outbreak showed the importance of preventing contamination of ready-to-eat foods from raw ingredients such as spices. Adulteration is an old concern too: Pliny warned of pepper bulked out with juniper berries.

Practical points: use pepper freely as a seasoning if it agrees with you. If you take prescription medicines, read supplement labels for piperine, black pepper extract, or BioPerine, which appear in many turmeric products and in some other supplements, and ask a pharmacist before taking them. Do not add piperine to a medication routine to “boost” it. If you try black pepper essential oil for its aroma, follow the product’s directions, keep it out of the eyes and away from children, and do not swallow it; the swallowing study used one minute of nasal inhalation, not oil taken by mouth. Keep pepper shakers and grinders out of reach of toddlers, and never put pepper in a child’s mouth or nose for any reason.