A radiologic method for measuring skin thickness and metacarpal index was used to investigate 41 postmenopausal women treated with estradiol (100-mg) subcutaneous implants (Organon, UK). All the women completed the first six months of the study, and 33 completed one year. Both skin thickness and metacarpal index increased to a statistically significant degree over the one-year period, with most of the increase occurring in the first six months of therapy. Skin thickness showed the largest increases, from a mean of 0.86 mm at the start of the study to 0.97 mm at six months and 1 mm at one year. The metacarpal index increased from a mean of 0.77 at the start of the study to a mean of 0.799 and 0.8 at six months and one year, respectively.