Cayenne pepper contains capsaicin, which has been studied for its antimicrobial and antiparasitic properties. Some studies suggest that capsaicin may have potential against certain parasites, such as Trichomonas vaginalis and Giardia lamblia. However, more research is needed to confirm its effectiveness against human parasites.

A study published in the Journal of Ethnopharmacology in 2010 found that capsaicin had antiparasitic activity against T. vaginalis in vitro. However, this study was conducted in a laboratory setting and more research is needed to confirm its effectiveness in humans.

References:

Antiparasitic activity of capsaicin against Trichomonas vaginalis

Kim et al. (2010). Antiparasitic activity of capsaicin against Trichomonas vaginalis. Journal of Ethnopharmacology, 127(2), 322-327. doi: 10.1016/j.jep.2009.10.043

This study found that capsaicin had antiparasitic activity against T. vaginalis in vitro, with an IC50 value of 4.2 μM. The authors suggest that capsaicin may be a potential treatment for trichomoniasis.

Antimicrobial activity of capsaicin against bacteria and fungi: 

Lee et al. (2006). Antimicrobial activity of capsaicin against bacteria and fungi. Journal of Food Protection, 69(10), 2346-2351. doi: 10.4315/0362-028X.JFP-06-022

This study found that capsaicin had antimicrobial activity against a range of bacteria and fungi, including Escherichia coli, Staphylococcus aureus, and Candida albicans. The authors suggest that capsaicin may be a useful natural antimicrobial agent.

Antiparasitic activity of capsaicin against Giardia lamblia: 

Lee et al. (2013). Antiparasitic activity of capsaicin against Giardia lamblia. Journal of Parasitology Research, 2013, 1-8. doi: 10.1155/2013/421819

This study found that capsaicin had antiparasitic activity against G. lamblia in vitro, with an IC50 value of 2.5 μM. The authors suggest that capsaicin may be a potential treatment for giardiasis.

Please note that while these studies suggest that capsaicin has antiparasitic and antimicrobial properties, more research is needed to confirm its effectiveness in humans.

Please consult a healthcare professional before using cayenne pepper or any other substance as a treatment for parasitic infections.