Clove

Syzygium aromaticum (in the family Myrtaceae) is a spice commonly referred to as Cloves, and appears to have some traditional usage as an aphrodisiac as well as for the medicinal purposes of dental disorders, respiratory disorders, headache and sore throat.^[1][2]

A 50% hydroalcoholic extract of syzygium aromaticum at 500mg/kg acutely is able to increase mounting of male mice with a potency nonsignificantly lesser than nutmeg (Myristica fragrans) and significantly less than 5mg/kg Viagra.^[3] Later, oral intake of 100-500mg/kg of a 50% hydroalcoholic extract of syzygium aromaticum for seven days showed dose-dependent libido enhancement with a potency still lesser than 5mg/kg Viagra.^[4]

Appears to have libido enhancing properties, although they are significantly less than that of Viagra and nonsignificantly less than the other libido enhancer tested (Nutmeg)

Oral ingestion of 15mg/kg Syzygium aromaticum in male mice for 35 days is associated with increased testicular Δ5 3β-HSD and 17β-HSD enzyme activity (thought to underlie the observed increases in testosterone).^[2]

30-60mg/kg dietary Syzygium aromaticum in male mice appears to induce testicular toxicity as assessed by serum testosterone and histological examination of the semineferous tubules.^[2]

The essential oil of clove possesses spermicidal activity in vitro when incubated alongside the sperm^[5] which may be related to the Eugenol content as this molecule has been known to possess anti-fertility actions.^[6]

Oral ingestion of an extract from the flower buds of Syzygium aromaticum at 15, 30, or 60mg/kg for 35 days in otherwise healthy male mice noted that the lowest dose of 15mg/kg increased serum testosterone 26% while the two higher doses were associated with reductions of testosterone (38-39%) secondary to testicular damage.^[2]