As can be seen, the percentage of free testosterone is tripled in women being treated with danazol.[18][23] The ability of danazol to increase free testosterone levels suggests that a portion of its weak androgenic effects are mediated indirectly by facilitating the activity of testosterone and dihydrotestosterone through the displacement of them from SHBG.[18][23] In addition to binding to and occupying SHBG however, danazol also decreases the hepatic production of SHBG and therefore SHBG levels, and so downregulation of SHBG may be involved as well.[9][18] Danazol likely decreases hepatic production of SHBG by reducing estrogenic and increasing androgenic activity in the liver (as androgens and estrogens increase and decrease, respectively, hepatic SHBG synthesis).[24] In accordance with the notion that suppression of SHBG is involved in the androgenic effects of danazol, the drug has synergistic rather than additive androgenic effects in combination with testosterone in bioassays (which is most likely secondary to the increased free testosterone levels).[20]