Black pepper (Piper nigrum) and white pepper (which is derived from the same plant but processed differently) have a long history of use in traditional medicine systems, such as Ayurveda and Traditional Chinese Medicine, for the management of colds and respiratory discomforts. These traditions often recommended pepper for its warming properties, ability to stimulate circulation, and as a remedy to help clear nasal congestion. The rationale was partly based on the spicy pungency of piperine, the active compound in pepper, which can help induce sneezing, promote expectoration, and temporarily relieve stuffy noses.

Scientific research investigating the direct antiviral effects of black or white pepper against common cold viruses (e.g., rhinoviruses, coronaviruses) is currently limited and not robust. Some laboratory studies have examined piperine for antimicrobial or immunomodulatory effects, but evidence for a measurable and clinically significant antiviral action in humans is lacking. Therefore, while pepper is widely used in traditional cold remedies, modern clinical trials have not substantiated its efficacy for treating or preventing colds. Its primary benefits may be limited to symptomatic relief (such as temporarily easing congestion) rather than direct antiviral activity.

In summary, the use of black and white pepper for colds is primarily justified by tradition, with minimal scientific backing for antiviral efficacy.