Capsaicin is the chemical compound that makes chili peppers hot. Found in the white pith and seeds of Capsicum plants, this alkaloid triggers pain receptors in mammals, creating the burning sensation pepper lovers chase.
The Science Behind the Burn
Capsaicin binds to TRPV1 receptors, proteins normally activated by physical heat and acidity. When capsaicin locks onto these receptors, your brain receives a false alarm: "Something is burning!" Your body responds with sweating, increased heart rate, and endorphin release.
This evolutionary trick helps peppers survive. Birds lack TRPV1 receptors sensitive to capsaicin, so they eat peppers without feeling heat. They then spread seeds across wide areas. Mammals, which would crush seeds with their teeth, feel the burn and usually avoid the plants.
Types of Capsaicinoids
Pure capsaicin accounts for about 70% of a pepper's heat, but four other capsaicinoids contribute to the experience:
- Dihydrocapsaicin: 20-30% of total heat, smooth and lingering
- Nordihydrocapsaicin: 5-10%, sharp and immediate
- Homocapsaicin: 1-2%, builds slowly
- Homodihydrocapsaicin: 1-2%, background warmth
These ratios vary between pepper varieties, explaining why habaneros feel different from cayennes even at similar Scoville levels.
Where Capsaicin Lives
Capsaicin concentrates in the placental tissue, the white membrane running along the inside of pepper walls. Seeds themselves contain little capsaicin, but they sit so close to the placenta that they absorb oils and taste hot.
Removing seeds and membranes reduces heat by 50-90%, depending on the pepper. This technique lets cooks enjoy pepper flavor without overwhelming burn.
Health Effects and Benefits
Capsaicin stimulates metabolism, promotes sweating, and triggers endorphin release. Some studies suggest it aids digestion, reduces inflammation, and provides temporary pain relief when applied topically.
The compound is also used in medical patches for arthritis and nerve pain. In concentrated form, capsaicin serves as a nonlethal deterrent in pepper spray.
Neutralizing Capsaicin
Water does not wash away capsaicin because the compound is lipophilic (fat-loving), not water-soluble. Instead, try:
- Dairy: Casein protein in milk binds to capsaicin and pulls it away from receptors
- Fats and oils: Dissolve capsaicin and carry it away from tissues
- Sugar or honey: Provides temporary relief by overwhelming taste receptors
- Alcohol: Ethanol dissolves capsaicin, though high-proof spirits work best
Capsaicin makes chili peppers more than vegetables. It transforms them into culinary weapons, health supplements, and cultural symbols. Understanding the molecule helps you control the heat, whether you cook, grow, or simply survive the burn.
Sources
Editorial transparency
Every release includes author credentials, publish dates, and citations.
- Author
- Republic of Heat Editorial Team
- Published
- Nov 8, 2025
- Updated
- Nov 8, 2025
- Republic of Heat lab notebooks
- Peer-reviewed capsaicin research
- Producer interviews & field notes