How Black Pepper Became an Absorption Story, 1985 to 2025

Piperine, a major compound in black pepper, slows liver enzymes that clear drugs. This history follows it from a 1985 rat study to a 1998 curcumin test and to tuberculosis regimens, with what each study measured and where the evidence stops.

Black pepper's absorption story starts with a 1985 paper in the *Journal of Pharmacology and Experimental Therapeutics*. It reported that piperine, a major active compound in pepper, slows several liver enzymes that break drugs down. The earliest human study we read dates to 1991. The 1998 study is the one with the headline number. Volunteers who took two grams of curcumin alone had blood levels that were undetectable or very low. Add 20 milligrams of piperine and the levels climbed, and the authors reported a 2,000 percent rise in bioavailability. ## How did piperine become a bioavailability ingredient? Bioavailability is the share of a dose that reaches the bloodstream. According to PubMed, the earliest study we could confirm is a [1985 paper by Atal and colleagues](https://pubmed.ncbi.nlm.nih.gov/3917507/). They tested piperine on rat liver tissue and in live rats, and found it inhibited several drug-metabolizing enzymes in a dose-dependent way. In rats given piperine by mouth, the strongest inhibition of one liver enzyme came within an hour and had faded by six hours. The authors called piperine a potent inhibitor of drug metabolism. Slow down the enzymes that clear a compound, and more of it survives long enough to reach the blood. ## What did the first human studies measure? Half of the six studies in the table below paired piperine with a drug. Every row reports blood-level results, and each study name links to its source. | Study | Who took part | Design | What was measured | Reported result | |---|---|---|---|---| | [Bano et al., 1991](https://doi.org/10.1007/BF00314996) | 6 per group, healthy volunteers | Propranolol 40 mg or theophylline 150 mg, alone or with 20 mg piperine daily for 7 days | Peak level and timing, total exposure (AUC), half-life | Propranolol peaked sooner and higher. Theophylline peaked higher and stayed longer. AUC rose with both. | | [Velpandian et al., 2001](https://doi.org/10.1007/BF03226378) | 6 healthy volunteers | Phenytoin 300 mg taken after a soup, with or without black pepper | Absorption rate, AUC, elimination | Faster absorption, higher AUC and slower elimination with pepper | | [Pattanaik et al., 2006](https://doi.org/10.1002/ptr.1937) | 20 patients with uncontrolled epilepsy | Phenytoin on one day, then phenytoin with 20 mg piperine on the next | AUC, peak level, absorption rate | Significant rises in AUC, peak level and absorption rate | | [Shoba et al., 1998](https://doi.org/10.1055/s-2006-957450) | Healthy volunteers (count not in abstract) | 2 g curcumin alone, or with 20 mg piperine | Serum curcumin | Undetectable or very low alone; much higher with piperine | | [Wightman et al., 2014](https://doi.org/10.1017/S0007114514000737) | 23 adults | 250 mg trans-resveratrol alone or with 20 mg piperine, on separate days | Brain blood flow, cognitive tasks, mood, blood pressure | Blood flow rose with the pair; the other measures did not change | | [Malhotra et al., 2025](https://doi.org/10.7759/cureus.97127) | 14 healthy adult volunteers | One dose of a turmeric extract, or 95% curcuminoids with 1% or 10% piperine | Peak blood concentration | 647.97 ng/mL (extract), 10.94 ng/mL (1% piperine), 663.60 ng/mL (10% piperine) | Two patterns stand out. Most groups had between 6 and 23 people. In every study in the table, the blood level measured belonged to another compound. The partners were curcumin, resveratrol and drugs, and none of the records we read paired piperine with a vitamin or a mineral. The drug rows matter most. [Velpandian and colleagues](https://doi.org/10.1007/BF03226378) describe phenytoin as having a narrow therapeutic index, so small shifts in blood level matter. ## How big were the curcumin and resveratrol effects? The 1998 study by Shoba and colleagues has the headline number, so read it closely. The abstract reports a 2,000 percent rise in human bioavailability and a 154 percent rise in rats, with no adverse effects reported. It gives neither the number of volunteers nor the design. Treat the percentage as the authors' calculation from a study whose size the abstract does not report. Our [turmeric and curcumin history](/blog/history/history-of-turmeric-and-curcumin-from-ayurveda-to-isolation) covers the curcumin side of this story. The 2025 Cureus study compared a turmeric extract with curcumin products containing 1 percent or 10 percent piperine. Only the 10 percent version matched the extract's peak level. Three of its six authors list Nisarga Biotech as an affiliation, and 14 volunteers is a small base for a comparison like this. Wightman and colleagues ran a randomized, double-blind, placebo-controlled crossover study. Their 23 adults took placebo, resveratrol alone, or resveratrol with piperine, on separate days. The pair raised blood flow in the front of the brain during thinking tasks, compared with placebo and with resveratrol alone. Cognitive scores, mood and blood pressure did not change, and plasma resveratrol levels did not differ between treatments. Blood flow was the only thing that moved. ## Why do the interaction studies point in both directions? [Bhardwaj and colleagues](https://doi.org/10.1124/jpet.102.034728) worked with cultured cells and with liver preparations from people, not with volunteers. Piperine inhibited the transport of digoxin and cyclosporine A across cell monolayers, and it inhibited CYP3A4, a major drug-metabolizing enzyme. The authors wrote that dietary piperine could affect blood levels of drugs handled this way, particularly when those drugs are taken by mouth. [Wang and colleagues](https://doi.org/10.1016/j.taap.2013.05.014) found the reverse. Piperine raised the expression of CYP3A4 and MDR1 (multidrug resistance protein 1) in human liver and intestinal cells and in a mouse model. The authors wrote that this finding challenges piperine's use as a bioavailability enhancer, and they advised caution during drug treatment. Two lab papers that point in opposite directions do not settle what happens inside a person. The [piperine monograph](/ingredients/piperine) walks through the drug-by-drug evidence. ## Where has piperine been used inside a prescription? Two randomized trials from India used piperine inside tuberculosis regimens. In [Patel and colleagues' trial](https://pubmed.ncbi.nlm.nih.gov/29313577/), 216 people with newly diagnosed sputum-positive pulmonary tuberculosis were randomized. The combination held rifampicin at 200 mg, isoniazid at 300 mg and piperine at 10 mg. At four weeks, 93 percent of that group reached sputum conversion, meaning sputum tests stopped finding the bacteria, against 84 percent on standard therapy. Cure at 24 weeks was 92 percent against 82 percent. Liver-enzyme rises occurred in 3 patients on the combination and 9 on standard therapy. [Nageswari and colleagues](https://doi.org/10.1016/j.jctube.2018.07.002) ran a smaller two-center study, and 63 patients completed it. Their piperine arm used 200 mg rifampicin with 10 mg piperine. In that arm, 22.22 percent of patients reported adverse drug events, against 36.84 percent on usual care. Piperine appears in these regimens as a designed part of the prescription, not as an add-on. Both trials gave whole regimens, so their numbers can't be assigned to piperine alone. ## What should a piperine label tell you? Our [NMN plus NR formula](https://mtangelvitamins.com/products/nmn-nr-cellular-wellness-supplement?utm_source=learn_hub&utm_medium=content&utm_campaign=blog_post&utm_content=history-of-black-pepper-from-spice-trade-to-piperine) lists 50 mg of Bioperine per two-capsule serving, and its panel gives no piperine milligrams. Some labels name the extract rather than the compound. This one states that Bioperine is a registered trademark of Sabinsa Corporation. None of the human records above tested piperine alongside NMN or NR, so that pairing has no direct data here. The [NMN plus NR research summary](/research/nmn-nr-tmg-resveratrol-zinc-synergistic-stack) covers the formula's other ingredients. Two cautions apply to any piperine product. We found no established upper intake level for piperine in the sources we checked. The human trials that stated a milligram dose used 10 to 20 mg. Ask a clinician or pharmacist first if you take phenytoin, rifampicin, propranolol, theophylline, or another drug cleared through CYP3A4. The 1985 paper used rats and mice. The newest human study in this post used 14 volunteers. Forty years on, a label can still name the extract and leave out the milligrams of piperine. ## Next reads - [The piperine monograph](/ingredients/piperine) has the dose and interaction tables we used to check the claims here. - [Turmeric and curcumin, from Ayurveda to isolation](/blog/history/history-of-turmeric-and-curcumin-from-ayurveda-to-isolation) traces the curcumin side of the 1998 study back to the Eastern texts. ### Related reading - [Betaine history: beets, homocysteine and trimethylglycine](/blog/history/history-of-betaine-from-sugar-beet-to-trimethylglycine) - [Resveratrol history: hellebore, knotweed and the French paradox](/blog/history/history-of-resveratrol-from-hellebore-to-french-paradox)