Linked from
The 9 pages that link to Piperine, each with the reason it gives.
TurmericRelated: Piperine is often combined with curcumin to increase its measured absorption.
PiperidineRelated: Piperidine was first isolated through the study of piperine.
PungencyRelated: It shows that pepper pungency comes from a different compound than chili heat.
CurcuminRelated: It is often combined with curcumin to increase systemic exposure.