Capsaicin: The Compound Behind the Burn

Capsaicin is the reason hot peppers make you sweat, cry, and come back for more. Whether you’re a hot sauce maker, a chilihead chasing the next level of heat, or just curious about what gives spicy food its kick, understanding capsaicin is key.

In this post, we’re diving into what capsaicin is. How hot it really gets, what it looks like, how it’s used in health and pain relief, where to find it, and how to handle it safely. Plus, we’ll break down the exact math behind ppm and Scoville Heat Units (SHU). This way you can confidently hit your heat targets in the kitchen or the lab.

What Is Capsaicin?

Capsaicin is a naturally occurring chemical compound found in chili peppers. It belongs to a family of compounds known as capsaicinoids. It’s the one primarily responsible for that signature burning sensation. Chemically, it’s written as C18H27NO3, and it interacts with your body by binding to TRPV1 receptors. The same ones that detect heat and pain. When capsaicin binds to them, your brain thinks you’re in contact with something dangerously hot, even though there’s no real damage being done.

This fiery compound evolved as a defense mechanism in peppers to stop mammals from eating them and damaging their seeds. Interestingly, birds don’t have the same reaction to capsaicin, which is why they can eat hot peppers with zero discomfort. This helps spread seeds far and wide.

How Hot Is Capsaicin?

If you’ve ever looked at a Scoville chart, you’ve seen numbers ranging from a few thousand to over two million SHU. Pure capsaicin sits at the very top of that chart at 16,000,000 Scoville Heat Units, making it the theoretical maximum heat achievable in nature.

To put that into perspective, jalapeños typically range from 2,500 to 8,000 SHU. Habaneros sit around 100,000 to 350,000 SHU. Superhot varieties like the Carolina Reaper can exceed 1.5 million SHU. But capsaicin itself? It’s heat in its purest form, not something you want to mess with unless you’re trained and prepared.

What Does Capsaicin Look Like?

In its purified state, capsaicin doesn’t look like anything you’d associate with peppers. It appears as a colorless to slightly off-white crystalline solid or waxy substance. It melts at around 62 to 65°C (144 to 149°F). It’s not water-soluble, which is why chugging water after eating a hot pepper never helps. Instead, it dissolves in fats, oils, and alcohols, which is why milk, yogurt, and even oil are your best bets for cooling down after an intense chili experience.

Health Uses of Capsaicin

Beyond lighting up your taste buds, capsaicin has legitimate health applications, especially when it comes to pain relief. Topical capsaicin creams are often used to treat conditions like arthritis, joint pain, and nerve-related pain. They work by overstimulating nerve endings, which causes the pain signals to temporarily stop firing. After repeated exposure, those nerves become desensitized to the stimulus, providing relief from chronic pain.

Over-the-counter creams typically contain a low concentration of capsaicin, usually between 0.025% and 0.1%. There are also high-dose prescription patches (like Qutenza) that contain 8% capsaicin and are applied in medical settings. While these products are safe when used correctly, they can still cause redness, warmth, or a burning sensation on the skin. Always consult a healthcare provider before using capsaicin therapeutically, especially if you have underlying skin or nerve issues.

How to Get Pure Capsaicin (And Should You?)

Extracting pure capsaicin is not something you can or should attempt at home. The process involves chemical solvents, supercritical CO₂, and chromatography, all industrial techniques that require specialized equipment and protective gear. Pure capsaicin is classified as hazardous. It can cause severe irritation to your skin, eyes, and lungs, even in tiny amounts.

For culinary or product development purposes, it’s better to purchase commercially prepared pepper extracts. These products come in a range of Scoville Heat Units, from 500,000 SHU to 16 million SHU — and allow you to precisely control the heat level in a hot sauce or spice blend. You can of course, make your own tinctures and extracts as well. Just a drop or two can completely change the heat profile of a batch. If you’re working with anything over 1 million SHU, gloves, goggles, and proper ventilation aren’t optional — they’re essential.

Where to Buy Capsaicin

Capsaicin in pure or concentrated form is available through different channels, depending on what you need it for. Culinary pepper extracts can be found through hot sauce retailers and specialty spice suppliers. They’re often sold as oil-based solutions such as Oleoresin Capsaicin or crystallized powders and should always list their SHU rating.

If you’re developing products in a lab setting or need pharmaceutical-grade purity, chemical supply companies like Sigma-Aldrich or Thermo Fisher offer research-grade capsaicin, typically at 95% to 99% purity. These purchases usually require a business or institutional account and come with material safety data sheets (MSDS) for proper handling and storage.

Handling and Safety Tips

Capsaicin may come from a natural source, but pure or concentrated forms can be dangerous if mishandled. Always wear gloves when working with capsaicin or hot pepper extracts. Avoid touching your face, especially your eyes and nose, and clean any utensils or surfaces thoroughly with oil followed by dish soap. Water alone won’t do the trick.

When diluting capsaicin, do so in oil or alcohol, never in water. And if you’re experimenting with high-SHU extracts in hot sauce making, test your formulas in small batches. Label everything clearly, and store it in a secure, child-proof location.

Conversion Corner: SHU vs. ppm (How to Calculate Heat Levels)

In product development, you’ll often see capsaicin concentrations listed in ppm (parts per million), especially in lab test results. To convert ppm to SHU, you can use a simple formula:

SHU = ppm × 16

This is because 1 ppm of capsaicin equals approximately 16 Scoville Heat Units. That number comes from the original methods used to scale heat based on dilution, now standardized through high-performance liquid chromatography (HPLC).

Let’s say your HPLC results show 1,250 ppm of capsaicin. Multiply that by 16, and you get 20,000 SHU. Reverse the formula to go from SHU to ppm: just divide by 16.

Need to calculate how much pure capsaicin you need to add to a 1 kg batch of sauce to hit your target heat? Here’s an example:

• Target: 50,000 SHU
• 50,000 ÷ 16 = 3,125 ppm
• That’s 3,125 mg, or 3.125 grams of pure capsaicin per kilogram of sauce

Working with pepper extracts instead? If your extract is rated at 1 million SHU and you want to make a 1 kg sauce at 20,000 SHU, use this formula:

(Target SHU ÷ Extract SHU) × batch weight = extract needed

In this case: (20,000 ÷ 1,000,000) × 1000 = 20 grams of extract.

It’s simple math, but the impact on flavor and intensity is huge.

Capsaicin is the beating heart of spicy food. Whether it’s bringing the fire to your hot sauce, delivering real relief in a pain cream, or simply helping peppers survive in the wild, it’s one powerful little molecule. And while it can be intimidating in its pure form, understanding how capsaicin works and how to safely use it opens up a whole new world of flavor, control, and creativity.

So the next time your mouth is on fire from a fresh habanero or your sauce tastes just right after a precise dose of extract, tip your cap to capsaicin — nature’s hottest chemical.