Capsaicin / CapsicumBotanical

• Energy intake at a meal (oral)Possibly helps

  A meta-analysis of 8 placebo-controlled RCTs (191 participants) found capsaicinoids cut ad libitum energy intake by an average of 74 kcal per meal [1].
  
  The reviewers put the threshold at roughly 2 mg of capsaicinoids for any effect, and flagged the trials as very heterogeneous [1]. Body weight itself was not consistently measured. ^[1]

• Weight loss (oral)Not shown to help

  A 12-week RCT in 77 overweight adults compared 2 mg/day with 4 mg/day. The 4 mg group reported 252 fewer calories a day than placebo, and still showed no significant body-weight difference at 6 or 12 weeks [1].
  
  One review describes capsaicin as mostly ineffective for meaningful fat loss on its own [2].
  
  In multi-ingredient trials pairing it with raspberry ketone, caffeine and green tea, weight-gain reductions ran 2–4%, with no way to tell how much came from capsaicin [7]. ^[1]

• Blood pressure and cholesterol (oral)Possibly helps

  ⚠ Two meta-analyses disagree, and the newer one undercuts itself.
  
  A 2021 systematic review and meta-analysis found no significant effect on systolic BP, diastolic BP or heart rate, with high between-study heterogeneity [10].
  
  A 2026 meta-analysis of 13 RCTs reported significant reductions in total cholesterol and diastolic BP [11]. The authors' own sensitivity analysis showed both results vanished when one single study was removed [11]. ^[11]

• Angina and blood vessels (topical patch plus animal data)Possibly helps

  A review in Open Heart describes capsaicin patches raising serum nitric oxide metabolites and improving exercise tolerance in angina patients [9].
  
  The same review notes capsaicin's direct effect on vascular smooth muscle is constriction, so any net blood-pressure result reflects competing mechanisms [9].
  
  It also cites case reports of acute hypertensive crisis after very high chili intakes [9]. ^[9]

• Osteoarthritis pain (topical)Likely helps

  NIH's PubChem summary of the trial evidence says topical capsaicin appears effective for osteoarthritis pain, drawing on 5 double-blind RCTs and 1 case-crossover trial [14].
  
  Those used 0.025%–0.075% formulations over 4 to 12 weeks [14]. Whether the effect is dose-dependent, holds across different joints, or changes over time is still uncertain [14]. ^[14]

• Neuropathic pain (topical, prescription)Likely helps

  The high-concentration 8% capsaicin patch (Qutenza) is specifically indicated for neuropathic pain from post-herpetic neuralgia [14].
  
  This is a prescription product applied in a clinic under medical supervision, not an over-the-counter cream [14]. ^[14]

• Burning mouth syndrome (topical oral gel)Possibly helps

  A small RCT in 22 women used topical oral capsaicin gel at 0.01% or 0.025%, three times a day for 14 days [13].
  
  Burning and stinging symptoms improved versus baseline, and the two concentrations did not differ from each other [13].
  
  4 of 22 participants dropped out over gastrointestinal side effects [13]. Twenty-two people is a pilot, not an answer. ^[13]

• Spicy food and mortality (observational)Possibly helps

  In a large prospective cohort, people eating spicy food almost daily had a 14% lower risk of death than those eating it less than weekly [8].
  
  Inverse associations also showed up for cancer, respiratory disease and ischemic heart disease deaths [8]. This is observational, and cannot show that capsaicin itself caused any of it. ^[8]

• Oral capsules and tablets (cayenne extract)The form used in the appetite and metabolic trials

  Elemental content

  Often labelled in Scoville Heat Units — commonly 40,000–100,000 SHU, against roughly 16 million SHU for pure capsaicin

  Absorption

  A 500 mg dried cayenne capsule holds around 1.2 mg of actual capsaicin

  Best for

  The form used in the appetite and metabolic trials [4][2]

• Delayed-release beadlets (Capsimax)Reducing the oral and gastric burn that plain capsules cause

  Elemental content

  Encapsulated capsaicinoid beadlets rather than loose powder

  Absorption

  Designed to hold off release until the upper intestine; in vitro, about 75% released by 4 hours in alkaline conditions

  Best for

  Reducing the oral and gastric burn that plain capsules cause [3]

• Over-the-counter topical cream, lotion, gelMuscle and joint pain at home

  Elemental content

  0.025%–0.075% capsaicin

  Absorption

  Applied several times a day and rubbed in well

  Best for

  Muscle and joint pain at home [14][12]

• Prescription 8% patch (Qutenza)Neuropathic pain such as post-herpetic neuralgia

  Elemental content

  8% capsaicin

  Absorption

  Applied in-clinic under medical supervision, not a home product

  Best for

  Neuropathic pain such as post-herpetic neuralgia [14]

• Low-concentration mucosal gelLocalized oral conditions — trialled in burning mouth syndrome

  Elemental content

  0.01%–0.025% capsaicin

  Absorption

  Applied directly to the affected oral tissue, three times daily in the trial protocol

  Best for

  Localized oral conditions — trialled in burning mouth syndrome [13]

• Multi-ingredient thermogenic blendsNothing in particular. Trials on these blends cannot isolate what capsaicin itself contributed

  Elemental content

  Capsaicin alongside caffeine, green tea extract, ginger and similar

  Absorption

  Varies by product, and capsaicinoid content is often not stated separately

  Best for

  Nothing in particular. Trials on these blends cannot isolate what capsaicin itself contributed [1][15]

• Oral burning and GI distress

  Gastrointestinal distress is the common oral side effect, showing up from about 4 mg/day of capsaicinoids [1].
  
  Starting low and taking capsules with food is the standard way people work around it [4]. ^[1]

• Topical skin reactions

  Common and local: application-site pain, dry skin, redness, itching and stinging [16].
  
  Rare but serious reports include anaphylaxis, burns and skin ulcers, difficulty breathing, facial, periorbital or pharyngeal edema, raised blood pressure, fainting, throat constriction and hives [16]. ^[16]

• Insulin and HDL cholesterol

  NIH's Office of Dietary Supplements notes that capsaicinoid supplementation around 4 mg/day may raise serum insulin and lower HDL cholesterol [1].
  
  ODS frames this as an effect of supplementation rather than a formal drug interaction. It still matters if you are managing insulin resistance or lipids alongside medication [1]. ^[1]

• Anticoagulants and topical salicylates

  A clinical drug-interaction database rates topical capsaicin with vitamin K antagonist anticoagulants, or with topical salicylates, as a severe interaction [16].
  
  The stated mechanism is an increased anticoagulant effect, drawn from human clinical trial and case-report evidence [16]. Concurrent use should be avoided where possible. ^[16]

• Blood pressure medication

  Oral capsaicin may push blood pressure in either direction depending on dose and context [4].
  
  Sources advise checking with a clinician first if you take antihypertensives [4][9]. ^[4]

• Aspirin

  ⚠ The two study types disagree, and nobody has settled it.
  
  An animal study found a capsaicin-containing chili extract reduced aspirin's bioavailability, which would in theory blunt its effect [2].
  
  A separate human study found capsaicin did not reduce aspirin's platelet-inhibiting action in practice [2]. ^[2]

Capsaicin comes from Capsicum peppers, and effectively nowhere else [5][18].

Bell peppers sit at 0 SHU; red jalapeños run 6,000–14,000 SHU, per a USDA petition document [18].

An HPLC analysis of market peppers measured bell-type peppers at 0–15.8 SHU, with capsaicin undetectable to about 1 µg/g [17].

The same analysis put green chili at 138.5 µg/g (~2,217 SHU), red chili at 309.3 µg/g (~4,949 SHU) and hot chili at 4,249 µg/g (~67,985 SHU) [17].

Broader literature ranges run from about 0.1 mg/g in chili pepper to 2.5 mg/g in red pepper, and up to 60 mg/g in concentrated oleoresin extract [17].

Most of the capsaicin sits in the internal veins and placenta holding the seeds, which is why pulling the veins and seeds cuts the heat [19][4].

A dietary survey in Riyadh measured average intake at 7.584 mg/person/day, about 0.108 mg/kg body weight — a useful real-world reference against supplement doses [17].

⚠ One commercial source lists oregano, cinnamon and cilantro as capsaicin sources [12]. No peer-reviewed or government source reviewed here corroborates that, and capsaicinoids are specific to Capsicum [5][18].

No source reviewed here compares morning against evening dosing [4].

What every source does say: take oral capsaicin with food, which buffers the burning and digestive upset it can otherwise cause [4].

Start at a low dose and raise it gradually, so the digestive tract desensitizes over time [4].

Delayed-release beadlet products are engineered around the same problem, releasing about 75% of their capsaicinoids by 4 hours in intestine-like conditions [3].

Trials that established the appetite effect generally dosed around mealtimes rather than testing time of day [1].