Black Pepper

Piper nigrum

Evidence: Strong

Black pepper contains piperine, an alkaloid known to enhance the bioavailability of various compounds, notably increasing and activating curcumin. It stimulates digestive enzyme activity and gastric acid secretion, thereby improving overall digestion and nutrient absorption.

There are 2087 peer-reviewed scientific studies on this ingredient.

Selected Study:

Shoba, G., Joy, D., Joseph, T., Majeed, M., Rajendran, R., & Srinivas, P. S. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Medica, 64(4), 353–356. https://doi.org/10.1055/s-2006-957450

Study Summary:

Study type: Prospective, single-dose, open-label cross-over pharmacokinetic study in eight healthy adult volunteers (plus a parallel rat experiment) to test whether 20 mg of piperine (black-pepper extract) alters the disposition of 2 g of oral curcumin. Each subject received curcumin alone and, after a wash-out, curcumin + piperine, with serial blood sampling for six hours.

Observed benefits:
Curcumin taken by itself produced “barely detectable” plasma levels, but when co-administered with piperine the peak serum concentration (Cmax) rose by ~2 000 % and overall exposure (AUC₀–₁h) increased more than twenty-fold in humans; rats showed a 154 % AUC rise. The elevation was evident within 15 minutes and persisted for ~2 hours.

Mechanisms of action:
The authors attributed the surge to piperine’s inhibition of intestinal and hepatic UDP-glucuronyl-transferase and P-glycoprotein efflux pumps, which slows curcumin conjugation and export, while increasing gut permeability and local blood flow. Later pharmacology reviews confirm these enzyme- and transporter-blocking effects and describe piperine as a “universal bio-enhancer.”

Side effects:
No changes in vital signs or laboratory safety parameters and no adverse events were reported at the tested doses (20 mg piperine + 2 g curcumin).

Strength of evidence:
Although the human arm involved only eight subjects and lacked blinding, its cross-over design, objective pharmacokinetic endpoints and concordant animal data make it a robust mechanistic proof-of-concept that piperine can greatly enhance curcumin absorption. The finding has been repeatedly cited and underpins many commercial turmeric-plus-black-pepper products, but larger randomized trials are still needed to confirm whether the pharmacokinetic boost translates into superior clinical outcomes and to clarify long-term safety when piperine is taken daily with other medications.