Is capsaicin (found in chili peppers) an aphrodisiac?

Question

Various web-sites claim that consuming capsaicin (the chemical found in chili peppers which makes them hot) has an aphrodisiac effect:

From berries.com:

Capsaicin is known to boost testosterone levels and increase libido. Chili peppers also have the ability to release endorphins, natural painkillers and your bodies response to the capsaicin.

Harper's Bazaar:

Just like cayenne's spicy on your tongue, it helps add spice to your sex life. "Hot peppers contain capsaicin, which creates heat and improves circulation and blood flow for erections," Isadora says. The peppers have an immediate effect [...]

Healthline casts some doubts on the claim:

Hot chilies: According to popular belief, capsaicin, the compound that gives hot chilies their spiciness, stimulates nerve endings on the tongue, causing the release of sex-drive-boosting chemicals. However, no studies support this belief.

There have been experiments involving injecting capsaicin locally to trigger erections in impotent men but this question is about ingestion.

Does consuming chili peppers have an aphrodisiac effect?

Answer 1

Yes, in rats

Guyamin, M et al. Effects of Capsicum frutescens L.(Siling Labuyo) on the sexual behavior of male Rattus norvegicus (Albino rats), Int J Sci Res, 2018, 7,1454--1458 writes

The present results indicated that the extract of the fruit of Capsicum frutescent Linn. (Siling labuyo) could be used as a stimulator of sexual behaviour in male Rattus norvegicus (Albino rats). This study thus supports the acclaimed aphrodisiac use. The data obtained revealed that the action of the test drug was due to the influence on both sexual arousal and performance.

Pelayo L.E. et al. PNM-06 Capsaicin Improves Sexual Behavior in Male Rat The Journal of Sexual Medicine, Volume 14, Issue Supplement_6, December 2017, Pages e384–e385 agrees:

Capsaicin facilitated the expression of the male rat sexual behavior.

In 2017, the effect had not been shown in humans.

Chilies and other spicy members of the genus Capsicum have long been believed to enhance sexual pleasure and function (Figure 27-6). The chemical responsible for the spicy flavor of these plants is capsaicin [58]. Capsaicin itself is used medicinally as a pain reliever. Capsaicin binds to a receptor called the vanilloid receptor subtype 1 (TRPV1), which modulates pain. Although beta endorphins act as analgesics and pleasure inducers there is little evidence that they enhance libido. To the contrary several rat studies have shown that increased B-endorphins suppressed mating behaviors [61, 62]. While capsaicin containing plants are medicinally valuable, there appears to be little evidence of their aphrodisiac value in humans.

ref: IsHak, W.W. et al (2017). Sex and Natural Sexual Enhancement: Sexual Techniques, Aphrodisiac Foods, and Nutraceuticals. In: IsHak, W. (eds) The Textbook of Clinical Sexual Medicine. Springer, Cham. https://doi.org/10.1007/978-3-319-52539-6_27