What is capsaicin?
Capsaicin is the main chemical that gives peppers their spiciness. It is most concentrated in the seeds, making them hotter than the pulp. When eaten, capsaicin stimulates pain receptors on the tongue, producing a sensation of heat. Sensitivity to capsaicin varies among individuals and increases with frequent consumption. The spiciness of chili peppers is measured in Scoville Heat Units (SHU), with jalapeños ranging from 2,500–8,000 SHU and habanero ranging from 100,000–350,000 SHU. Capsaicin supplements are derived from chili peppers and are measured in SHU, which typically ranges from 40,000-100,000, but due to encapsulation, the heat cannot be fully felt.
- Chemical formula C18H27NO3
- UNII S07O44R1ZM
- CAS No. 404-86-4
- IUPAC name (6E)-N-[(4-hydroxy-3-methoxyphenyl)methyl]-8-methylnon-6-enamide
health benefits
relief the pain
Capsaicin is a known analgesic that has been approved by the FDA as a prescription-grade pain reliever. It has anti-inflammatory properties and desensitizes nerve cells that transmit pain signals. Topical capsaicin is effective for a variety of health conditions, such as lower back pain. Capsaicin patches are used to treat diabetic peripheral neuropathy and provide long-lasting pain relief. In addition, capsaicin can help relieve discomforts such as arthritis, cluster headaches, jaw pain, and psoriasis.
Mechanism
Capsaicin induces local allergy in the skin, leading to loss of nociceptor fiber function, thereby reducing substance P and relieving pain. This alters pain mechanisms by temporarily losing membrane potential, interrupting the transport of neurotrophic factors, and constricting nerve fiber terminals.
Can improve muscle endurance
Research on capsaicin supplementation to improve athletic performance has yielded mixed results. One review found that it did not improve aerobic endurance, but it did enhance muscular endurance. This is due to capsaicin's effect on calcium release in skeletal muscles, which is required for contraction. However, capsaicin supplementation to improve athletic performance is currently not recommended.
blood pressure level
A systematic review found that eating spicy food 6 to 7 days a week was associated with a 14% lower risk of all-cause mortality compared with eating spicy food less than once a week. However, while ingesting hot peppers may lower blood pressure, it may also increase unhealthy LDL cholesterol and lower healthy HDL cholesterol. These findings are based on observational studies and cannot determine cause and effect. Other dietary and lifestyle factors may also contribute to the observed patterns.
weight management
Spicy foods like chili peppers are thought to boost metabolism and aid weight loss. Research shows that the capsaicin in chili peppers can increase calorie burning and reduce appetite. However, research results are conflicting, with some linking high intake of spicy foods to obesity. It's worth noting that there are other more effective weight management habits before relying solely on cayenne pepper.
How to use capsaicin
Capsaicin is found in chili peppers and chili powder and can be taken orally or as a supplement. There are no set dosage guidelines. Pain relief is most effective when applied topically in the form of a cream, gel, lotion or patch, which contains varying concentrations of capsaicin. Nasal sprays containing capsaicin may help relieve allergies and cluster headaches, but more research is needed. It is recommended to consult a healthcare provider before using capsaicin topicals or supplements.
Capsaicin Supplements – Proper Dosage
People often take capsaicin supplements because food sources may not provide enough of this compound. Most supplements contain cayenne pepper, which is high in capsaicin. Typical dosage is 2-6 mg per day, and each capsule usually contains 500 mg of cayenne pepper. Since supplement dosage has not been standardized, it is recommended to start with a low dose to avoid side effects. Additionally, it’s important to purchase capsaicin supplements from reputable sources that have been third-party verified to ensure safety and quality.
Oral absorption
Capsaicin is absorbed orally, with absorption rates ranging from 50% to 90%, depending on the animal. Peak blood concentration is reached within 1 hour. After absorption, capsaicin is slightly metabolized by the epithelial cells of the small intestine. In humans, 26.6 mg of pure capsaicin was detected in plasma 10 minutes after ingestion. The peak plasma concentration was 2.47 ± 0.13 ng/ml, occurring at 47.1 ± 2.0 minutes.
local analgesics
Capsaicin is commonly used as a local analgesic and is available in a variety of cream, liquid, and patch formulations of varying strengths. However, it may also be found in some dietary supplements. Capsaicin is a naturally occurring plant stimulant in chili peppers and is a synthetic pharmaceutical preparation. The most recent FDA-approved capsaicin is Qutenza, an 8% capsaicin patch dermal delivery system indicated for the treatment of neuropathic pain associated with postherpetic neuralgia.
Absorption for external use
Topical capsaicin is readily absorbed through human skin, but when administered topically or transdermally, very little is absorbed into the bloodstream. One study analyzed plasma concentrations of capsaicin in patients using a 179 mg patch, showing a maximum observed value of 17.8 nanograms/ml.
Metabolism and elimination pathways
Capsaicin is metabolized in the liver after oral administration but has little or no metabolism in the intestine. In laboratory tests using human liver microsomes and the S9 fragment, capsaicin is rapidly metabolized into three major metabolites: 16-hydroxycapsaicin, 17-hydroxycapsaicin, and 16,17-hydroxycapsaicin. Vanillin is a minor metabolite. Cytochrome P450 enzymes may play a role in liver metabolism. In human skin studies, capsaicin undergoes slow biotransformation and remains mostly unchanged.
After ingesting 26.6 mg of capsaicin, its half-life is approximately 24.9 ± 5.0 minutes. The half-life of a topically applied 3% capsaicin solution is approximately 24 hours. The elimination half-life of the 179 mg capsaicin patch is 1.64 hours.
Capsaicin is primarily excreted via the kidneys in its raw and glucuronide forms, but is also present in small amounts in feces and urine. In animal studies, less than 10% of the dose was found in feces.
Is capsaicin safe?
Capsaicin found naturally in spicy foods is safe and well tolerated. Capsaicin is also generally safe when used topically in over-the-counter or prescription forms. However, long-term use of high-dose oral capsaicin supplements may pose health risks, including organ damage and high blood pressure. Pregnant and breastfeeding individuals, as well as children, should avoid oral capsaicin supplements. Check with your healthcare provider before taking any new supplements.
Potential drug interactions
The capsaicin in chili peppers is unlikely to interact with medications. However, higher doses of capsaicin supplements may interfere with anticoagulants, diabetes medications, aspirin, and bronchodilators. Capsaicin supplements may enhance the effects of anticoagulant medications, possibly increasing the risk of bleeding. When taken with antidiabetic medications, they may also lower blood sugar levels, possibly causing hypoglycemia. Animal studies suggest that large amounts of capsaicin-rich chili peppers may reduce the effectiveness of oral aspirin and inhibit the excretion of medications used to treat asthma, but further research in humans is needed.
Capsaicin side effects
Capsaicin in contact with the eyes can cause severe irritation, conjunctivitis, and tearing.
Capsaicin is a strong irritant to skin and eyes, causing burning and pain if it comes in contact with eyes and skin, and can cause lung tissue to swell. It can also irritate the oral mucosa. Consuming capsaicin in its natural food form can cause side effects such as heartburn, burning throat, nausea, flushing, sweating, runny nose, burping and digestive problems.
It can also irritate the respiratory system, causing lung irritation, coughing, and bronchoconstriction. Other respiratory effects include laryngospasm, swelling of the larynx and lungs, chemical pneumonitis, respiratory arrest, and central nervous system effects.
When used topically, capsaicin-based products are generally well tolerated. Warning signs of adverse effects from topical use include severe burning, itching, coughing, sneezing, and pain or blistering at the application site.
Symptoms of systemic toxicity include disorientation, fear, loss of body movement control, hyperventilation, tachycardia, and pulmonary edema.
The acute oral LD50 and transdermal LD50 in mice are 47.2 mg/kg and >512 mg/kg respectively (MSDS). MSDS shows that capsaicin is mutagenic to bacteria and yeast.
May cause burning sensation
Capsaicin supplements often cause a burning sensation in the digestive tract. They can worsen acid reflux and heartburn symptoms. However, over time, the body becomes accustomed to capsaicin, resulting in less discomfort. Taking the supplement with food can help reduce the burning sensation.
May cause an increase in body temperature
Capsaicin supplements can increase body temperature and cause discomfort because they affect heat-regulating receptors in the body. While it's usually not dangerous and unlikely to cause a fever, some people may be more sensitive to this sensation. Additionally, capsaicin supplements may increase blood pressure, so be sure to talk to your healthcare provider if you take blood pressure medications. To minimize side effects, start with a low dose and gradually increase to the desired level.
where to find
You can easily find natural foods rich in capsaicin in your grocery store, such as chili peppers, paprika, and hot sauce. Capsaicin-based creams, lotions, and nasal sprays are available over the counter or with a prescription to address specific health concerns. Please consult your healthcare provider for guidance.
pharmacodynamics
Capsaicin activates the TRPV1 receptor, a transmembrane receptor-ion channel complex. This complex can be activated by high temperature, low pH and endogenous lipids. When activated, the channels open and allow calcium and sodium ions to enter, causing depolarization. This causes A-delta and C fibers to generate action potentials, producing sensations such as warmth, tingling, and burning. Capsaicin also causes long-term activation of these receptors, resulting in diminished responses to sensory stimulation. It also affects enzyme activity, cell structure and nociceptor function.
What happens to capsaicin in the environment?
Based on its chemical properties, capsaicin should not be very mobile in soil. It is also not expected to turn into vapor. Bacteria in the soil break down capsaicin. Capsaicin is not expected to enter groundwater, but may leach out of the soil in some cases. Half of the capsaicin applied to the soil breaks down within 2 to 8 days.
Most wildlife avoid capsaicin because of its strong smell and taste. However, birds cannot taste capsaicin and are not repelled by it. Capsaicin is toxic to bees and other beneficial insects. Researchers believe that capsaicin and similar compounds protect the seeds inside peppers from fungal attack.
