Although male testes are responsible for huge testosterone secretion, testosterone can be produced by other organs both in males and females. So, women do have testosterone. Similarly, estrogen is also produced in men and not only in women. In addition, both sexes produce the androgen and the estrogen receptors, so endogeneous or external testosterone will be active in women. Among other things, testosterone supplementation have been shown to be useful in clinical studies conducted on women suffering from hypoactive sexual desire.
Woodis et al., Pharmacotherapy. 2012 Jan;32(1):38-53. doi: 10.1002/PHAR.1004.