Capsimax for Weight Control: Does It Work & Is It Safe?

Answer:

What Is Capsimax?

Capsimax by OmniActive Health Technologies is a branded cayenne pepper (Capsicum annuum) extract found in supplements promoted for weight loss, such as MST Capsimax, Burn Evolved, and Cellucor SuperHD Thermogenic Fat Burner.

Each 100 mg of Capsimax (which is made up of 15% to 25% cayenne pepper extract, 45% to 55% sugar, and 30% to 35% cellulose gum) contains 2 mg of capsaicinoids, of which 1.2% to 1.35% is capsaicin, 0.6% to 0.8% is dihydrocapsaicin, and 0.1% to 0.2% is nordihydrocapsaicin (Rogers, BMC Obes 2018).

How Capsimax Might Work

Capsaicinoids in Capsimax are thought to contribute to weight loss by suppressing appetite, increasing thermogenesis (energy use), and promoting fat burning (Elmas, J Am Nutr Assoc 2022; Irandoost, Phytother Res 2021; Janssens, Appetite 2014; Reinbach, Clin Nutr 2009). However, as discussed below, clinical studies evaluating Capsimax have shown mixed evidence of benefit for weight loss.

Is Capsimax Effective?

For Weight Loss

Capsimax might improve weight loss, possibly by reducing calorie intake increasing energy use, but the effects appear to be modest, at best, and not all research agrees.

A company-funded study among 77 healthy men and women (average age 30) showed that taking Capsimax at low-dose (100 mg providing 2 mg of capsaicinoids) or high-dose (200 mg providing 4 mg of capsaicinoids) once daily after breakfast for 12 weeks did not significantly affect body mass or body composition compared to placebo, although those taking high-dose Capsimax consumed 252 fewer Calories per day than those in the placebo group (Urbina, Appetite 2017). A subsequent analysis of this study in which the results were adjusted for variables that can affect weight loss — such as age, weight, BMI, blood pressure, and calorie intake — found that those in the high-dose group showed slightly greater loss of body fat (-5.91%) and fat mass (-6.68%) compared to those in the placebo group. The low-dose group showed no significant improvement, even after adjusting for these variables (Rogers, BMC Obes 2018).

Taking 100 mg of Capsimax daily for 7 days was shown to slightly increase fasting blood levels of GLP-1 (which reduces hunger) by about 13% compared to baseline versus a 3% decrease in the placebo group. Capsimax also increased resting energy expenditure by about 155 Calories/day compared to placebo. Weight loss was not assessed in this study (Rawal, Acad J Sports Sci Med 2026).

Other Uses of Capsaicinoids

Capsaicinoids — particularly capsaicin — have been evaluated for other conditions, although some of these are topical use.

Cayenne pepper and/or capsaicin are sometimes taken to reduce symptoms of Raynaud's phenomenon based on preliminary evidence that these compounds can promote blood vessel dilation when used orally or topically (McCarty, Open Heart 2015) and may create a "warming sensation" when applied topically (Szolcsanyi, Temperature (Austin) 2015). However, there do not appear to be any clinical studies confirming this benefit.

A clinical study among people with fibromyalgia showed that applying capsaicin topically to affected areas several times daily, in addition to taking standard medication, improved pain better than taking medication alone. However, the study was not placebo-controlled, which limits the reliability of the results (Casanueva, Rheumatol Int 2013).

Over-the-counter creams, lotions, and patches containing capsaicin have been evaluated topically for nerve pain conditions, including post-herpetic neuralgia (nerve pain after shingles) and diabetic neuropathy, but most research suggests only modest benefit, if any. For more details, see our article comparing topical capsaicin with topical menthol, which includes information about side effects of topical capsaicin.

Is Capsimax Safe?

A small safety study among 12 healthy females (average age 43) showed that taking 100 to 500 mg of Capsimax containing 2 to 10 mg of capsaicinoids daily for one week did not cause any adverse effects (Deshpande, J Toxicol 2016). The long-term safety of Capsimax does not appear to have been evaluated in clinical research.

Some people have reported in Amazon reviews that products containing only Capsimax, such as MST Capsimax Supplement, caused stomach pain, burning sensation in the lower abdomen, heartburn, and discomfort when passing stools.

Cost

MST Capsimax Supplement, which appears to be one of the few products available in the U.S. that contains only Capsimax, costs $21.95 for sixty 100-mg capsules (37 cents per 100-mg serving). Keep in mind that clinical studies evaluating Capsimax for weight loss found evidence of possible benefit only when taken at a daily dose of 200 mg (which would cost 74 cents/day).

Products containing Capsimax in combination with other ingredients tend to cost more and often contain less Capsimax than used in clinical studies. For example, Burn Evolved costs $1.63 per 2-capsule daily serving but provides only 50 mg of Capsimax. Cellucor SuperHD Thermogenic Fat Burner costs up to $1.50 per 3-capsule daily serving, but the amount of Capsimax is not listed — it is part of a proprietary blend (which we consider to be a red flag for supplements).

Be aware that some products marketed as containing Capsimax, such as StayAlive Cayenne Pepper Extract and Underground Labs Capsi, do not appear to actually contain this branded ingredient. Although the descriptions of these products on Amazon mention "Capsimax," a review of the Supplement Facts panels for these products indicates that the products do not contain this specific branded ingredient.

The Bottom Line

There is mixed evidence as to whether Capsimax helps with weight loss, and some people report unpleasant GI side effects. Consequently, we don't think this ingredient is worth using for weight loss. However, if you want to try it, we would suggest considering a product that contains only Capsimax, as there does not appear to be evidence that taking Capsimax in combination with other ingredients is beneficial — and other ingredients included in weight loss supplements may cause their own side effects (see our Weight Loss Supplements Review).