Capsaicin: Uses, Benefits, Dosage, and Side Effects

Capsaicin is a phytochemical primarily found in chili peppers. It is used in dietary supplements for weight loss, increased fat burning, reduced appetite, and improved exercise performance.

Table of Contents

Outcome Summary

This tier list summarizes the primary outcomes of capsaicin supplementation and grades them from A (best) to E (worst), based on up-to-date scientific evidence.

A: Best in class for that particular outcome. Recommended for practically everyone.
B: Worth the money for most people and backed by scientific evidence to provide significant positive effects.
C: Might be worth trying, but the effects are small to modest, or the research is limited in size and scope.
D: Generally ineffective, although not harmful.
E: Negative or even harmful effects.

You can find references in the detailed research review of each outcome below.

Effect	Tier (A = best, E = worst)	Summary
Strength Training Performance	B	Capsaicin increases strength training performance. Some people can do a few more repetitions and feel less effort during sets.
Endurance Training Performance	D	Taking capsaicin does not meaningfully improve aerobic endurance.
Thermogenesis & Fat Oxidation	B	The majority of studies indicate that capsaicin significantly boosts calorie- and fat-burning.
Appetite	C	Capsaicin may reduce appetite and increase fullness, but likely not to the point where it affects long-term body weight control.
Weight Loss	C	Supplementing with capsaicin may reduce calorie intake and slightly boost weight loss, but the effect is small and only useful as part of a weight-loss program with proper diet and exercise.
Pain Relief	B	Topical capsaicin may offer relief from minor pain in muscles and joints. It can also help with neuropathic pain, but only in some people, and only high doses are effective.
Metabolic Health	C	Capsaicin may help lower blood sugar and control blood lipids, but human research is limited.
Inflammation	B	Capsaicin is a powerful antioxidant and can help protect the body’s cells from oxidative damage.

What Is Capsaicin?

Capsaicin is the most well-known of the capsaicinoids, a group of naturally occurring compounds found in chili peppers. It is responsible for their spicy flavor.

Beyond its uses in spicy foods and hot sauces, capsaicin is a common active ingredient in weight-loss supplements due to claims that it boosts metabolism and promotes fat burning. It’s also used in topical creams for pain relief, particularly in arthritis, muscle pain, and nerve pain, because it temporarily desensitizes pain receptors.

Due to its diverse pharmacological and therapeutic properties, it has been the subject of extensive research.

How Does Capsaicin Work?

Capsaicin works by binding to TRPV1 (Transient Receptor Potential Vanilloid 1) receptors in the mouth, skin, or digestive tract.

TRPV1 is a protein in sensory nerve cells and functions as an ion channel. It is activated by stimuli like heat, acidic conditions, pain, and capsaicin and is involved in pain perception, inflammation, and temperature regulation.¹ ² ³

When you ingest capsaicin, a long list of physiological responses occur:

When capsaicin binds to TRPV1 receptors, signals go out to the brain, making you perceive a sensation of heat even though no actual temperature change has occurred, resulting in a burning feeling in your mouth and throat.
To counteract the pain from capsaicin, your body may release endorphins, which are natural pain relievers. This can sometimes lead to a sense of euphoria, the same way some people feel after eating spicy food.
After ingestion, capsaicin continues to interact with TRPV1 receptors in the gastrointestinal tract, leading to increased acid production and sometimes resulting in stomach discomfort. But despite the painful sensation it causes when ingested, it can provide pain relief with the right dosage and timing.

Capsaicin has a mild thermogenic effect, meaning it can increase the body’s heat production and metabolism, which is why it’s often included in fat-burning supplements.
It can stimulate circulation and cause vasodilation (the widening of blood vessels), leading to a temporary flush or feeling of warmth throughout the body.
Capsaicin is also believed to have anti-inflammatory, antioxidant, and potential anti-cancer properties.

Does Capsaicin Increase Exercise Performance?

Capsaicin has been studied for its potential to enhance exercise performance. While it has promise in improving resistance training performance, the role of capsaicin on endurance performance is less clear.

It might increase exercise capacity through five main mechanisms:⁴

Boosting the release of calcium within muscle cells, which is essential for muscle contractions.
Enhancing fatty acid oxidation for increased energy availability and fat-burning during exercise.
Reducing the sensation of pain and increasing the tolerance for discomfort during exercise.
Reducing how quickly muscles use up glycogen, thus delaying the onset of fatigue and allowing them to keep working longer.
Increasing the release of a chemical called acetylcholine, which transmits signals that improve both explosive power and endurance performance from nerves to muscles.

Endurance Training

Several early animal studies demonstrated improved endurance, such as increased swimming time to exhaustion in rats. A couple studies indicate improvements in running performance in humans, but the effects are inconsistent.

According to a meta-analysis of several studies, most using doses of 12 mg taken 45 minutes before exercise, there is no notable difference between capsaicin supplementation and placebo regarding aerobic performance outcomes.⁵

The effect size for aerobic endurance was minimal, suggesting that even if there were any effect, it would be trivial. Subgroup analyses confirmed these findings, showing no significant difference in time-trial or time-to-exhaustion tests.

In addition, capsaicin supplementation does not seem to meaningfully reduce the rating of perceived exertion (RPE) during aerobic endurance tests, which could explain the lack of any significant performance boost. Some studies report increased fat oxidation and potential glycogen sparing, but these effects do not translate into significant improvements in endurance performance.

In short, capsaicin supplements are generally ineffective for aerobic and endurance performance.

Strength Training

A number of studies between 2018 and 2024 examine how capsaicin affects resistance training performance. Most demonstrate that it has generally positive effects, although a few fail to show any benefits.⁶ ⁷

Capsaicin delays fatigue during strength exercises, allowing for more repetitions completed before failure. In one study, participants were able to perform 14–21% more reps compared to a placebo.
Several studies show that capsaicin improves the total weight lifted during a training session, with an increase of up to 23% more weight lifted compared to the placebo group in some studies.
In several studies, participants report lower perceived exertion (about 6.4% less effort) after capsaicin supplementation. Capsaicin also increased the fatigue index by around 15%, meaning it helps reduce the subjective feeling of tiredness during a workout.
Some studies demonstrate that capsaicin enhances muscle strength during movements like knee extensions, with peak torque (the highest amount of rotational force muscles can produce during a single movement) increasing by around 6% in those who took the supplement.

Resistance Training Vs. Endurance Training

Capsaicinoids are better at improving strength training performance than endurance training, although the exact reasons why are not fully understood.

Capsaicinoids activate a receptor in the body called TRPV1. They might also interact with the IGF-1 signaling pathway. IGF-1 stimulates muscle protein synthesis and promotes strength and muscle hypertrophy, and studies suggest a connection between IGF-1 and TRPV1 activation.
The benefits of TRPV1 and IGF-1 signaling activation are more suited to the high-intensity, short-duration efforts of resistance training, whereas its effects on endurance performance are inconsistent and less significant.

In short, capsaicin supplementation improves resistance training performance, such as muscular endurance (more repetitions before failure) and a lower rate of perceived exertion compared to placebo. However, it does not significantly boost aerobic endurance.

Does Capsaicin Increase Thermogenesis and Fat Oxidation?

Research suggests that capsaicin and other capsaicinoids increase thermogenesis (the process by which the body generates heat through metabolic activity) and fat oxidation (the process by which fat is broken down and used for energy), particularly in conditions of negative energy balance (you burn more calories than you eat).⁸ ⁹ ¹⁰ ¹¹

Capsaicin increases the body’s energy expenditure (how many calories you burn) by raising the resting metabolic rate (RMR). By activating a receptor called TRPV1, which is found in sensory neurons, the body burns more calories through heat production. On average, this boost is about 30 to 50 kcals per day (up to 70 kcals per day in obese people), so your body burns more calories at rest with a capsaicin supplement.
It does not seem to increase energy expenditure during exercise.
Capsaicin also encourages the body to burn more fat, partly because it enhances the release of norepinephrine, a hormone promoting fat breakdown. In most studies, fat oxidation increases significantly with a capsaicin supplement.
In addition, studies suggest that capsaicin might increase the amount of brown adipose tissue (BAT), which is more metabolically active than white fat tissue and helps burn calories and produce heat.
Capsaicin lowers RQ (a measure of what type of fuel your body uses (carbs vs. fat)), shifting the body towards burning more fat than carbs. A lower RQ indicates that more fat is being burned relative to carbohydrates.

In short, capsaicin helps burn more calories and fat by increasing your metabolism and pushing the body to use fat as its primary energy source, all thanks to its interaction with specific receptors in the body. However, individual responses may vary; some studies did not observe significant effects.

Does Capsaicin Help With Appetite Regulation?

Capsaicin has been shown to decrease appetite and increase fullness, potentially leading to reduced calorie intake.¹² ¹³

When people eat meals with capsaicin in a eucaloric diet (where they consume just enough calories to maintain their current weight), they tend to feel fuller for longer.
Capsaicin can also lower the amount of food people eat when given the freedom to eat as much as they want, meaning it could prevent overeating by increasing feelings of satiety.
In situations where people are eating fewer calories than they need (negative energy balance), like on a weight-loss diet, capsaicin might help reduce the usual increase in hunger that comes with calorie restriction. People consuming capsaicin report a lower desire to keep eating after dinner, even when in a calorie deficit.

In short, capsaicin may reduce appetite and increase satiety, although the exact mechanisms aren’t fully understood. However, the effects are modest and might not help significantly with body weight management in the long run.

Does Capsaicin Help With Weight Loss?

Capsaicin can potentially help with body weight control and weight loss by increasing energy expenditure and fat oxidation, improving fat metabolism, and reducing appetite, calorie intake, and body fat accumulation.

The latest and largest meta-analysis to date found that capsaicin supplementation could be part of a weight management program with a modest but statistically significant reduction in body mass index (BMI) by 0.25 kg/m², body weight by 0.51 kg, and waist circumference by 1.12 cm in studies lasting from 4 to 12 weeks.¹⁴

Regular consumption of capsaicin might help reduce energy intake and body weight slightly over time, but these effects are not large enough to be a standalone solution for weight loss. The effects are generally modest but more pronounced with high doses and when taking the supplement for a long time.

Also, while capsaicin might suppress appetite, it’s likely not enough to protect against weight gain and obesity in the long run.

In short, capsaicin has the potential for weight loss and body weight management. However, it is not a magic bullet and is more likely to be useful as part of a complete weight management strategy, where diet and exercise are the more important factors.¹⁵ ¹⁶

Does Capsaicin Provide Pain Relief?

Capsaicin may have pain-relieving effects when applied topically in cream form.¹⁷ ¹⁸ ¹⁹ ²⁰

It works in a way that might seem contradictory. Initially, capsaicin triggers pain by activating so-called TRPV1 receptor However, with repeated exposure or higher doses, these receptors become less responsive or desensitized, reducing the nerve’s ability to signal pain. That’s because capsaicin depletes chemicals, for example substance P, in the nerves that transmit pain signals, leading to longer-term pain relief.

It’s helpful for general muscle and joint pain and treating certain chronic pain conditions, like post-herpetic neuralgia (pain after shingles), neuropathic pain (nerve pain) like diabetic neuropathy, and conditions where the nerves are oversensitive to stimuli. Only high-dose topical capsaicin offers significant pain relief for neuropathic pain. Low-dose capsaicin-based creams can be useful for muscle aches but are typically no more effective than a placebo cream for neuropathic pain.

In short, capsaicin helps with pain by overwhelming and “wearing out” the nerves that send pain signals, making them less sensitive to pain after repeated exposure. It doesn’t work for everyone, though, and there is no way of knowing if it is helpful to someone before trying it.

Does Capsaicin Improve Metabolic Health?

Metabolic syndrome is a collection of conditions, including central obesity (belly fat), high blood pressure, abnormal cholesterol levels, and high blood sugar. Capsaicin may have beneficial effects on metabolic health, but the evidence is not entirely conclusive.²¹ ²² ²³ ²⁴

Animal studies suggest capsaicin can help reduce blood sugar and improve fat metabolism, potentially preventing or mitigating metabolic syndrome. However, there are far fewer human studies.
Some large population studies found that people who eat chili peppers regularly tend to have lower risks of cardiovascular diseases and live longer. But clinical trials haven’t shown strong evidence that capsaicin significantly improves blood sugar or blood pressure. However, recent research supports capsaicin in reducing blood lipids and “bad” cholesterol in patients with metabolic syndrome.
Capsaicin may also improve metabolic health indirectly by boosting the growth of beneficial gut bacteria. A healthier gut environment, supported by capsaicin, could help reduce low-grade inflammation, which is common in obesity and metabolic syndrome. However, again, more human data is needed for any definite conclusions and recommendations.

In short, while capsaicin shows promise for improving metabolic health through gut health and reducing inflammation, blood sugar, and cholesterol, more evidence is needed, especially in humans, to confirm these effects.

Does Capsaicin Have Anti-inflammatory Effects?

Capsaicin is high in antioxidants, which help neutralize free radicals, harmful molecules that can damage cells, proteins, and DNA.²⁵ ²⁶ ²⁷

Free radicals are unstable atoms that can damage the body. They are produced naturally in the body but can also come from exposure to outside sources like UV rays, cigarette smoke, air pollutants, and other environmental factors. Without antioxidants to keep them in check, free radicals can damage cells and cause oxidative stress, which is linked to early aging and diseases like cancer and heart disease.

As a natural antioxidant, capsaicin can help slow down the chain reaction of free radical damage in the body and block biochemical changes from radiation, protein oxidation, and the breakdown of fats, which are all processes associated with free radicals.

Additionally, capsaicin can work with drugs and other medical treatments to bolster their effects. For example, capsaicin may act as a radioprotector. It can shield cells from radiation damage, making it beneficial when the body is exposed to radiation as part of treatments that are necessary but harm cells in other ways at the same time.

In short, capsaicin’s antioxidant properties help protect cells from damage, reduce the risk of disease, and may even enhance the effectiveness of medical treatments.

Safety of Capsaicin

Capsaicin supplements are generally considered safe for most people when taken at the recommended dosages. Common side effects include feeling hot, heartburn, and nausea, which, while unpleasant, are not dangerous. It has been generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA) for use in foods.²⁸

Capsaicin can irritate the gastrointestinal (GI) tract, causing adverse reactions like heartburn, abdominal pain, nausea, or diarrhea, particularly in high doses. Individuals with sensitive stomachs or GI conditions like irritable bowel syndrome (IBS) should be cautious with capsaicin. Also, those with poorly controlled hypertension and those who have recently experienced a cardiovascular event should not use capsaicin.

Contact with eyes can cause severe tearing, conjunctivitis, and mucosal irritation. A small number of people can also get an allergic reaction from capsaicin.

There is also some debate regarding capsaicin’s potential carcinogenic effects. Although it is suggested that capsaicin could act as a carcinogen due to its interaction with certain enzymes, long-term studies in populations with high chili consumption have not shown adverse effects like increased cancer risk.²⁹

In short, capsaicin is generally safe when used appropriately, both in capsule form and as a topical application, but very high doses or prolonged exposure may cause irritation and other side effects.

Capsaicin Dosage

The recommended dosage of capsaicin supplementation varies depending on the intended purpose. These are the dosages used in the studies mentioned above.

Capsaicin capsules typically provide anywhere from 0.25 mg to 1 mg of capsaicin per capsule, depending on the product and its intended use. Some capsules are marketed for metabolism-boosting or fat-burning purposes, and may contain higher doses, while others designed for joint pain relief may have lower amounts. Always check the specific product label for the exact capsaicin content.

Metabolic Effects and Weight Management

Capsaicin capsules for weight management and metabolic health are typically taken in doses ranging from 2 mg to 12 mg per day.

There is a dose-dependent effect where high doses increase factors like metabolic rate and fat oxidation more than low doses.

Starting with smaller doses can be a good idea, as capsaicin can cause gastrointestinal discomfort and a burning sensation in the stomach for some people.

Taking it during or after a meal can help reduce gastrointestinal discomfort, as capsaicin can be harsh on an empty stomach.

Exercise Performance

A typical dose is 12 mg of capsaicin 45 minutes to an hour before training, both strength training and endurance exercise.

Topical Form for Pain Management

Over-the-counter capsaicin creams typically contain 0.025% to 0.075% capsaicin. These are applied to the affected area 3 to 4 times daily and are used to manage osteoarthritis, rheumatoid arthritis, neuropathic pain, and musculoskeletal pain.

Prescription-strength 8% capsaicin patches are placed on the affected area for 60 minutes (up to 90 minutes for feet) and can provide pain relief for several months. Due to the potential for severe discomfort, such high-concentration treatments are administered under medical supervision.

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