Things That Can Make You Less Attractive, According To Science

Stress
A 2013 study from researchers in Finland, South Africa, the UK, Latvia, and Estonia found that Latvian women with high levels of the stress hormone cortisol were perceived by heterosexual men in Latvia as less attractive. Even though the men didn't know the women's cortisol levels (only the researchers did), it seemed to affect the women's perceived attractiveness. The researchers say that's possibly because low cortisol (and lower stress) levels indicate health and fertility.