Capsaicin
(E)-N-[(4-hydroxy-3-methoxyphenyl)methyl]-8-methylnon-6-enamide
TL;DR
Capsaicin, the pungent compound in chili peppers, modestly raises energy expenditure and trims appetite in trials, but pooled weight loss is about 0.5 kg and higher oral doses sometimes upset the stomach. Topical creams are studied for pain.
Ideal For
- Adults with overweight seeking a small add-on to diet and activity changes
- People who already tolerate spicy food
- Adults using over-the-counter cream for minor joint or muscle aches
Avoid If
- You are allergic to capsicum or chili peppers, or to other nightshade-family plants (cross-reactions can occur)
- You take anticoagulant or antiplatelet medicine and have not asked your prescriber
- You are pregnant or breastfeeding and considering oral capsules (data are limited)
- You would apply cream to broken skin, near the eyes, or on a child under 18 without a doctor's advice
Frequently Asked Questions
Does capsaicin help you lose weight?
Is a capsaicin supplement the same as capsaicin cream?
Why does capsaicin burn, and does it fade?
Can capsaicin capsules upset your stomach?
Does capsaicin lower blood sugar?
Is capsaicin safe while breastfeeding?
Overview
Capsaicin is the major pungent principle in hot peppers. It switches on TRPV1, a heat-sensing receptor on sensory nerves, which explains both the burn and most of what researchers have studied: a small rise in energy expenditure, a nudge to appetite when swallowed, and a pain-dulling effect when applied to skin. Supplements deliver capsaicinoids (capsaicin and close relatives) in capsules, while creams and patches deliver capsaicin through the skin. These are different products with different evidence.
For weight, the best evidence is a set of meta-analyses of small trials. Fifteen randomised trials (762 people) found capsaicin lowered body weight by about 0.5 kg, BMI by 0.25 kg/m2 and waist circumference by about 1.1 cm. In 9 trials of capsaicin or capsinoids, energy expenditure rose by about 245 kJ (59 kcal) a day, an effect seen in studies of people with a mean BMI above 25 but not below it. Capsaicinoids taken before a meal cut intake at that meal by about 74 kcal, though the trials disagreed with each other. The authors of these reviews call the effects small, and a trial of capsaicin after a very-low-energy diet found it did not limit weight regain.
Tolerability decides whether the oral doses are usable. At 4 mg a day, 23% of one trial's participants reported gastrointestinal distress, and gut infusions raised fullness only alongside pain, burning, nausea and bloating. Topical capsaicin is better studied for pain: Cochrane found that the single-application 8% patch gives modest benefit in nerve pain, while for low-concentration cream it found too few data to judge and what exists suggests little beyond placebo cream. In osteoarthritis, topical capsaicin at licensed doses may be about as effective as topical anti-inflammatory gels. Overall evidence for capsaicin as a supplement is low: real but small effects, little long-term data and common side effects.
How It Works
- Capsaicin activates TRPV1, a heat-sensing receptor on sensory nerves, which produces the burning sensation and starts the other effects.
- In mice, sensory nerves that carry TRPV1 raise energy expenditure by activating sympathetic nerves and adrenaline secretion, and the thermogenic effect of TRPV1 agonists is attributed to brown adipose tissue activation in mice and humans.
- Capsiate, a non-pungent relative, activates TRPV1 receptors in the gut but not the mouth, which is why capsinoids are studied as a milder alternative.
- Fullness after a gut infusion of capsaicin did not come with a change in GLP-1 or PYY, and tracked with pain, burning, nausea and bloating instead.
- On skin, capsaicin first enhances sensitivity, then reduces it, and after repeated applications causes persistent desensitisation of the treated nerve endings.
Quick Facts
- Pungent compound in chili peppers
- Pooled weight loss about 0.5 kg
- Capsaicin or capsinoids: +59 kcal/day burned
- 4 mg/day caused GI distress in 23%
- Cream is not the same as capsules
Health Concerns Addressed
Osteoarthritis
Likely a modest short-term pain reliever for knee osteoarthritis as a topical cream or gel, with low-certainty evidence and frequent burning.
Peripheral Neuropathy
The 8% patch gives modest benefit in nerve pain; for low-concentration cream the data are too thin to judge.
Supporting Research27 studies
The effects of capsaicin intake on weight loss among overweight and obese subjects: a systematic review and meta-analysis of randomised controlled trials
Zhang W, Zhang Q, Wang L +4 more
significant reduction on BMI
Capsaicin for osteoarthritis pain
Laslett LL, Jones G
Capsaicin appears to be effective for osteoarthritis pain
Efficacy of symptomatic control of knee osteoarthritis with 0.0125% of capsaicin versus placebo
Kosuwon W, Sirichatiwapee W, Wisanuyotin T +2 more
0.0125% capsaicin gel was an effective treatment in mildly to moderately painful OA knees
Capsaicin and capsiate could be appropriate agents for treatment of obesity: A meta-analysis of human studies
Zsiborás C, Mátics R, Hegyi P +4 more
the energy expenditure increased (245 kJ/day
The effect of Capsaicinoids or Capsinoids in red pepper on thermogenesis in healthy adults: A systematic review and meta-analysis
Irandoost P, Lotfi Yagin N, Namazi N +4 more
significantly increased RMR
Treatment of arthritis with topical capsaicin: a double-blind trial
Deal CL, Schnitzer TJ, Lipstein E +4 more
Significantly more relief of pain was reported by the capsaicin-treated patients than the placebo patients
Could capsaicinoids help to support weight management? A systematic review and meta-analysis of energy intake data
Whiting S, Derbyshire EJ, Tiwari B
reduced ad libitum energy intake by 309.9kJ (74.0kcal)
Effect of topical capsaicin in the therapy of painful osteoarthritis of the hands
McCarthy GM, McCarty DJ
Capsaicin reduced tenderness (p less than 0.02) and pain (p less than 0.02) associated with OA
The effects of capsaicin and capsiate on energy balance: critical review and meta-analyses of studies in humans
Ludy MJ, Moore GE, Mattes RD
The magnitude of these effects is small.
High strength capsaicin cream for osteoarthritis pain: rapid onset of action and improved efficacy with twice daily dosing
Schnitzer TJ, Posner M, Lawrence ID
High strength capsaicin provided greater pain relief with a more rapid onset of action
Effects of twelve weeks of capsaicinoid supplementation on body composition, appetite and self-reported caloric intake in overweight individuals
Urbina SL, Roberts MD, Kephart WC +4 more
H-CAP consumed less kcal/d compared to PLA at 12 WK
The analgesic efficacy of topical capsaicin is enhanced by glyceryl trinitrate in painful osteoarthritis: a randomized, double blind, placebo controlled study
McCleane G
topical capsaicin and glyceryl trinitrate have an analgesic effect in painful osteoarthritis
Effect of capsaicin on substrate oxidation and weight maintenance after modest body-weight loss in human subjects
Lejeune MP, Kovacs EM, Westerterp-Plantenga MS
capsaicin treatment has no limiting effect on 3-month weight regain
Individual responses to topical ibuprofen gel or capsaicin cream for painful knee osteoarthritis: a series of n-of-1 trials
Persson MSM, Stocks J, Sarmanova A +4 more
Irrespective of equal efficacy overall, 59% of people displayed a greater response to one treatment over the other
Capsaicin-induced satiety is associated with gastrointestinal distress but not with the release of satiety hormones
van Avesaat M, Troost FJ, Westerterp-Plantenga MS +4 more
significantly increased satiety
Randomized, Double-Blind, Placebo-Controlled Trial of Intraarticular Trans-Capsaicin for Pain Associated With Osteoarthritis of the Knee
Stevens RM, Ervin J, Nezzer J +4 more
CNTX-4975 1.0 mg produced a significant decrease in OA knee pain through 24 weeks
Short- and long-term effects of capsaicin supplementation on glycemic control: a systematic review and meta-analysis of controlled trials
Foshati S, Moradi S, Tavassoly M +1 more
neither acute nor chronic beneficial or detrimental effects on blood glucose and insulin levels
Acute administration of capsaicin increases resting energy expenditure in young obese subjects without affecting energy intake, appetite, and circulating levels of orexigenic/anorexigenic peptides
Rigamonti AE, Casnici C, Marelli O +4 more
capsaicin does not exert hypophagic effects
Effects of novel capsinoid treatment on fatness and energy metabolism in humans: possible pharmacogenetic implications
Snitker S, Fujishima Y, Shen H +4 more
Capsinoids were well tolerated
Topical capsaicin (high concentration) for chronic neuropathic pain in adults
Derry S, Rice AS, Cole P
generated more participants with moderate or substantial levels of pain relief than control
Topical capsaicin (low concentration) for chronic neuropathic pain in adults
Derry S, Moore RA
low-concentration topical capsaicin is without meaningful effect beyond that found in placebo creams
Systematic review of topical capsaicin for the treatment of chronic pain
Mason L, Moore RA, Derry S +2 more
moderate to poor efficacy in the treatment of chronic musculoskeletal or neuropathic pain
The Effectiveness and Safety of Topical Capsaicin in Postherpetic Neuralgia: A Systematic Review and Meta-analysis
Yong YL, Tan LT, Ming LC +4 more
topical capsaicin is a promising treatment option for specific patient groups
Efficacy and safety of topical capsaicin in the treatment of osteoarthritis pain: A systematic review and meta-analysis
Tshering G, Posadzki P, Kongkaew C
topical capsaicin may increase burning sensation at the application site
The relative efficacy of topical non-steroidal anti-inflammatory drugs and capsaicin in osteoarthritis: a network meta-analysis of randomised controlled trials
Persson MSM, Stocks J, Walsh DA +2 more
capsaicin in licensed doses may be equally effective
The treatment of functional dyspepsia with red pepper
Bortolotti M, Coccia G, Grossi G +1 more
Red pepper was more effective than placebo in decreasing the intensity of dyspeptic symptoms
Tolerability of Capsaicinoids from Capsicum Extract in a Beadlet Form: A Pilot Study
Deshpande J, Jeyakodi S, Juturu V
tolerable and safe for weight management studies
Safety Information
Potential Side Effects
Oral: stomach pain, burning, nausea and bloating. In a 12-week trial 9 of 39 people (23%) taking 4 mg a day reported gastrointestinal distress, versus none taking 2 mg a day. Topical: burning at the application site is common (risk ratio 5.56, number needed to harm 3 in osteoarthritis trials); it can be severe and generally fades over several days of regular use. The 8% patch can cause substantial application pain and transient rises in blood pressure, according to its FDA label.
Contraindications
Allergy to capsicum or chili peppers; topical use on wounds or damaged skin, or near eyes, lips, nose or mucous membranes.
Drug Interactions
- Anticoagulant or antiplatelet drugs: LactMed advises using Capsicum cautiously because it may increase bleeding risk; ask your prescriber first.
- Other medicines: laboratory tests on human liver enzymes found minimal effect at food-level exposure, but this is not a clinical interaction study.
Pregnancy & Breastfeeding
Pregnancy: Not enough evidence to judge
Breastfeeding: Not enough evidence to judge
Dosage Guidelines
Dosage Used in Studies
2-4 mg
Best Time to Take
The single-meal appetite studies dosed capsaicinoids before eating; the 12-week trial abstract does not say when capsules were taken.
Best Form
A capsule that states capsaicinoids in milligrams for oral use; a labelled over-the-counter cream for minor aches; capsinoids if pungency is a problem.
Bioavailability
Topical capsaicin is poorly absorbed into the bloodstream, according to LactMed. Absorption of oral capsaicinoids was not reported in the trials reviewed here.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| Appetite and body composition (12-week trial) | 2-4 mg capsaicinoids a day | 4 mg a day lowered self-reported intake but 23% reported GI distress; 2 mg a day did not |
| Before a meal (appetite) | At least 2 mg capsaicinoids | A meta-analysis suggested about 2 mg is the minimum that cuts intake at that meal; results varied widely between trials |
| High-dose weight maintenance trial | 135 mg capsaicin a day for 3 months | Did not limit weight regain after a very-low-energy diet |
| Functional dyspepsia (one small trial) | 2.5 g red pepper powder a day for 5 weeks | 30 patients; symptom scores fell about 60% versus under 30% with placebo |
| Topical cream, over-the-counter | 0.025% cream, thin film, 3-4 times daily | Adults 18 and over; children under 18 should ask a doctor; wash hands afterward |
| Prescription patch | Single 8% patch applied by a clinician | Applied under controlled conditions, often after local anaesthetic, because of the initial intense burn |
Forms Compared
Capsaicinoid capsules (oral)
Best for Appetite, energy expenditure
The form tested for appetite and weight; trials used about 2-4 mg a day of capsaicinoids
Red pepper powder
Best for Functional dyspepsia (limited data)
One small trial in functional dyspepsia used 2.5 g a day for 5 weeks
Capsinoids (non-pungent)
Best for Limited weight data (one trial, no weight change)
Capsaicin relatives from sweet peppers; one 12-week trial used 6 mg a day
Topical cream (0.025-0.075%)
Best for Minor joint and muscle aches
Over-the-counter creams are labelled for minor muscle and joint aches; trials of 0.075% cream studied nerve pain
High-concentration 8% patch
Best for Postherpetic and HIV nerve pain
A single clinician-applied patch, about 100 times the strength of conventional creams; benefit is expected to last about 12 weeks
Food & Timing
The single-meal appetite studies gave capsaicinoids before a meal.
Medical Disclaimer
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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.