A landmark pharmacokinetic study (PMC3918523) demonstrated that co-administering 20 mg of piperine with curcumin increased serum curcumin concentrations by approximately 2,000% in humans. Piperine achieves this by inhibiting UDP-glucuronosyltransferase and CYP3A4, the primary enzymes that rapidly conjugate and degrade curcumin in the intestinal wall and liver. A few grinds of black pepper (enough to provide roughly 5–20 mg of piperine) is sufficient to produce a meaningful enhancement effect. Piperine also increases absorption of several other nutrients including selenium, beta-carotene, and some water-soluble vitamins, though these effects are less studied than the curcumin interaction.
Piperine inhibits NF-κB, the master inflammatory transcription factor, and suppresses COX-2 expression, sharing mechanistic overlap with NSAIDs but at the low doses present in culinary use. Preclinical studies have shown piperine reduces TNF-α and IL-1β production. These anti-inflammatory effects at culinary concentrations are modest and largely incidental to black pepper’s primary value as a bioavailability enhancer.