Disclosed is a safe substance which can inhibit the activity of 
aromatase (an 
enzyme capable of converting 
androgen into 
estrogen) to thereby effectively treat and / or prevent a sex 
hormone-dependent 
disease such as 
breast cancer occurring in a female person after 
menopause, as well as a 
climacteric disorder in a male person and 
metabolic syndrome caused by the accumulation of a 
visceral fat. Specifically disclosed is a therapeutic and / or prophylactic agent for a sex 
hormone-dependent 
disease, which is characterized by comprising at least one herbal extract selected from the group consisting of “Kokeiten” (golden root), 
prunella spike, sweet 
hydrangea leaf, 
milk thistle, a jasmine tea, “Bokusoku” (a 
bark of 
Quercus acutissima or a closely related 
plant thereof), “Tencha” (sweet tea), “Karensou” (
Eclipta prostrata), “Youbaihi” (a 
bark of 
Myrica rubra Sie b. et Zucc.), French maritime pine, 
betel palm, 
asparagus, “Rouro” (a root of 
Rhaponticum unifloru m DC. or Echinops latifolius Tausch), “Ryoukyou” (a 
rhizome of 
Alpinia officinarum Hance), rooibos tea, rhubarb, pu-erh tea, 
green tea, “Ougon” (a root of 
Scutellaria baicalensis Georgi), St. John's wort (
Hypericum perforatum L.), licorice, “Senrikou” (
Senecio scandens Buch.-Ham.), wintergreen, “Kashi” (a matured fruit of 
Terminalia chebula Retz.), “Yagotou” (a 
bark of 
Mallotus japonicus), polygnum root, barrenwort (
Epimedium Herb), guarana, “Ouhi” (a bark of 
Prunus jamasakura Sieb. ex. Koidz. or a closely related 
plant thereof), Argy's wormwood, sticky 
rehmannia, Japanese cornel, Asiasarum root, cinnamon, peony root, pine needle and amla fruit.