Capsaicin is found almost exclusively in chili peppers, the fruits of plants in the genus Capsicum. No other common fruit, vegetable, or grain produces it. If a food delivers that familiar burning heat on your tongue, it either contains chili peppers directly or uses an extract derived from them. A few related compounds in ginger and black pepper activate the same pain receptor, but they are chemically distinct from capsaicin itself.
Chili Peppers Are the Primary Source
The Capsicum genus includes over 200 varieties grouped into more than 30 species, with five that have been domesticated and are widely grown for food. Nearly every chili pepper within these species produces capsaicin, from mild varieties like Anaheim and poblano to intensely hot ones like habanero and Carolina Reaper. The one major exception is the bell pepper, which belongs to the same species (Capsicum annuum) yet produces no detectable capsaicinoids at all.
Common peppers you’ll find at grocery stores or in prepared foods include jalapeño, serrano, cayenne, Thai bird’s eye, habanero, Scotch bonnet, and dozens of dried varieties like guajillo, ancho, pasilla, and de árbol. All of these contain capsaicin, just in very different concentrations. The Scoville scale measures that intensity: bell peppers sit at 0 SHU, jalapeños range from 2,000 to 8,000 SHU, and habaneros jump to 100,000 to 350,000 SHU. The higher the number, the more capsaicin per gram of pepper.
Where Capsaicin Hides Inside the Pepper
If you’ve ever been told the seeds are the hottest part, that’s not quite right. Capsaicin is synthesized in the placenta, the white, spongy tissue (sometimes called the pith or ribs) that runs down the center of the pepper and anchors the seeds. Capsaicin concentration in the placenta is roughly ten times higher than in the outer flesh or the seeds themselves. The placenta accounts for 65 to 95 percent of a pepper’s total pungency, while the fleshy walls contribute just 2 to 25 percent and the seeds only 2 to 12 percent.
This is why removing the inner ribs and seeds before cooking dramatically reduces a dish’s heat. The seeds taste hot mainly because they sit in direct contact with the placenta and pick up capsaicin on their surface, not because they produce much on their own.
Processed and Prepared Foods With Capsaicin
Beyond whole peppers, capsaicin shows up in a wide range of products:
- Hot sauces and chili pastes: Tabasco, sriracha, sambal oelek, gochujang, and harissa all derive their heat from capsaicin-containing peppers.
- Dried spices: Cayenne powder, crushed red pepper flakes, chili powder blends, paprika (especially hot paprika), and chipotle powder are ground dried peppers with varying capsaicin levels.
- Prepared foods: Salsas, kimchi, curry pastes, chili oils, and many snack seasonings (like the coating on spicy chips) contain capsaicin from pepper ingredients or oleoresin capsicum, a concentrated extract.
- Pepper extracts: Some ultra-hot sauces and novelty foods use purified capsaicin extract rather than whole peppers to reach extreme heat levels.
If an ingredient list mentions any type of pepper, chili, cayenne, or capsicum extract, the product contains capsaicin.
Related Compounds in Ginger and Black Pepper
Ginger and black pepper produce a burning sensation that feels similar to chili heat, and there’s a biological reason for that. The pungent compound in black pepper (piperine) and the one in ginger (zingerone) both activate the same pain receptor that capsaicin targets. All three compounds are structurally related and can even cross-desensitize, meaning heavy exposure to one can temporarily reduce your sensitivity to another.
However, they are far less potent. In lab measurements, piperine required roughly 50 times the concentration of capsaicin to produce a comparable nerve response, and zingerone required concentrations thousands of times higher. So while ginger and black pepper share a similar mechanism, they are not sources of capsaicin itself, and their heat intensity is not in the same range.
How Cooking Affects Capsaicin Content
Capsaicin is a remarkably stable molecule at normal cooking temperatures. Roasting, sautéing, or simmering peppers below about 190°C (375°F) does not significantly reduce their capsaicin content. In one study, red pepper seeds roasted at 100°C retained nearly all their capsaicin, dropping only slightly from 36.5 to 32.6 mg/kg. But at 200°C (about 400°F), capsaicin dropped to roughly half its original level, and above 190°C it begins to break down rapidly.
This means most stovetop cooking, slow simmering, and moderate oven roasting will preserve a dish’s heat. If you want to reduce capsaicin’s bite, cooking at very high temperatures for extended periods will help, but the most effective strategy is still physical removal of the placenta and seeds before cooking.
How Your Body Absorbs It
Capsaicin is fat-soluble, which is why drinking water does little to relieve the burn while milk, yogurt, or fatty foods coat the receptor and wash the compound away. Once swallowed, capsaicin is absorbed passively in the stomach and upper small intestine with greater than 80 percent efficiency. You don’t need to pair it with fat for your body to absorb it, but fat-containing foods and dairy are the most effective way to neutralize the burning sensation in your mouth.