Food and Dishes Use
Because of the burning sensation caused by capsaicin when it comes in contact with mucous membranes, it is commonly used
in food products to provide added spice or "heat" (piquancy), usually
in the form of spices such as chili powder and paprika. In high concentrations,
capsaicin will also cause a burning effect on other sensitive areas, such as
skin or eyes. The degree of heat found within a food is often measured on the
subjective Scoville scale. Because people enjoy the heat, there has long been a
demand for capsaicin-spiced products like curry, chili con carne, and hot
sauces such as Tabasco sauce and salsa.
It is common for people to experience
pleasurable and even euphoric effects from ingesting capsaicin. Folklore among
self-described "chiliheads" attributes this to pain-stimulated
release of endorphins, a different mechanism from the local receptor overload
that makes capsaicin effective as a topical analgesic.
Research and Pharmaceutical Use
Capsaicin is used as an analgesic in
topical ointments, nasal sprays (Sinol-M), and dermal patches to relieve pain,
typically in concentrations between 0.025% and 0.1%. It may be applied in cream
form for the temporary relief of minor aches and pains of muscles and joints
associated with arthritis, backache, strains and sprains, often in compounds
with other rubefacients.
It is also used to reduce the symptoms of
peripheral neuropathy such as post-herpetic neuralgia caused by shingles.
Capsaicin transdermal patch (Qutenza) for the management of this particular therapeutic
indication (pain due to post-herpetic neuralgia) was approved as a therapeutic
by the U.S. FDA, but a subsequent application for Qutenza to be used as an
analgesic in HIV neuralgia was refused.
Although capsaicin creams have been used
to treat psoriasis for reduction of itching, a review of six clinical trials
involving topical capsaicin for treatment of pruritus concluded there was
insufficient evidence of effect.
There is insufficient clinical evidence to
determine the role of ingested capsaicin on a variety of human disorders,
including obesity, diabetes, cancer and cardiovascular diseases.
Pepper Spray and Pests Use
Capsaicin is also an active ingredient in
riot control and personal defense pepper spray agents. When the spray comes in
contact with skin, especially eyes or mucous membranes, it produces pain and
breathing difficulty, discouraging assailants. Refer to the Scoville scale for
a comparison of pepper spray to other sources of capsaicin.
Capsaicin is also used to deter pests, specifically
mammalian pests. Targets of capsaicin repellants include voles, deer, rabbits,
squirrels, bears, insects, and attacking dogs. Ground or crushed dried chili
pods may be used in birdseed to deter rodents, taking advantage of the
insensitivity of birds to capsaicin. The Elephant Pepper Development Trust
claims the use of chili peppers to improve crop security for rural African
communities[citation needed]. Notably, an article published in the Journal of
Environmental Science and Health in 2006 states that "Although hot chili
pepper extract is commonly used as a component of household and garden
insect-repellent formulas, it is not clear that the capsaicinoid elements of
the extract are responsible for its repellency."
The first pesticide product using solely
capsaicin as the active ingredient was registered with the U.S. Department of
Agriculture in 1962.
Equestrian Sports Use
Capsaicin is a banned substance in equestrian sports because of its
hypersensitizing and pain-relieving properties. At the show jumping events of
the 2008 Summer Olympics, four horses tested positive for the substance, which
resulted in disqualification.
