Capsaicin, the compound in chili peppers that makes them spicy, is said to support weight loss. Proponents claim that this natural substance can help speed up metabolism and reduce fat tissue, as well as curb overeating by taming your appetite.

The Research on Capsaicin and Weight Loss

While scientists have yet to confirm that capsaicin can serve as a weight loss aid, some early studies suggest that this spicy chemical may be of some benefit if you are trying to slim down.

For a report published in Appetite in 2014, scientists sized up previously published clinical trials investigating the potential benefits of capsaicin compounds on energy intake. In their review, the report’s authors found evidence that consumption of a minimum of 2 mg of capsaicin compounds (known as capsaicinoids) before a meal reduced energy intake by 74 calories during the meal.

Here’s a look at several other findings from studies on capsaicin and weight loss:

Appetite

The mechanism behind capsaicin’s purported satiating effect may be attributed to an altered preference for carbohydrate-rich foods over foods with a higher fat content, according to the Appetite study.

In a study published in the American Journal of Clinical Nutrition in 2016, capsaicin intake promoted satiety but didn’t affect levels of the satiety hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). Instead, the researchers suggest that capsaicin-induced satiety may be related to increased gastrointestinal symptoms, such as pain, a burning sensation, nausea, and bloating.

Metabolism

Consumption of capsaicin and the nonpungent compounds in chili peppers (known as capsinoids) may increase energy expenditure and fat oxidation, according to a report published in Critical Reviews in Food Science and Nutrition. Researchers reviewed previously published studies and found that in studies where participants had a mean body mass index (BMI) falling within the overweight or obese range, ingestion of capsaicin or capsinoids increased energy expenditure and showed signs of increased fat oxidation.

Body Fat

In addition to reducing energy intake, preliminary research suggests that capsaicin intake may reduce the waist-to-hip measurement ratio. In a study published in Appetite in 2017, researchers found that capsaicin intake at 2 mg per day increased the waist-to-hip ratio at six weeks compared to high-dose capsaicin intake or a placebo. Body composition, however, was not significantly affected.

Possible Side Effects

Although capsaicin is generally considered safe when consumed in moderation in foods, capsaicin supplements may cause side effects such as stomach irritation, stomach pain, bloating, and the aggravation of ulcers and heartburn.

High intake of capsaicin, however, may lead to negative health effects. For instance, there’s some concern that consuming large amounts of capsaicin from chili peppers may increase the risk of gastric cancer. (Low intake of capsaicin, however, appears to protect against gastric cancer, according to an analysis.)

In addition, capsaicin supplements may interact with certain medications (including aspirin and blood-thinning drugs) and supplements. They shouldn’t be taken within two weeks of a scheduled surgery.

There’s also some concern that the use of capsaicin supplements or topical capsaicin may trigger coronary spasm and raise the risk of a heart attack in some people.

It’s important to keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

The Takeaway

While it’s too soon to recommend capsaicin supplements (or a high intake of chili peppers) for weight loss, increasing your capsaicin intake somewhat by adding chili peppers, cayenne pepper, or paprika in small amounts to your cooking may be beneficial to your overall health (partly due to the compound’s antioxidant effects).

If you’re still considering the use of capsaicin supplements, make sure to consult your health care provider first to see if it’s right for you.