Table 2 Reasons why study results on androgen effects have, likely, been inconsistent

Not all androgens are equally agonistic with AR

Androgens have genomic and non-genomic effects on follicle maturation

A specific androgen may have different effects:

   • Based on concentration: inside or outside of therapeutic ranges

   • Based on synergism/antagonism with other factors: synergism with FSH, etc.

Androgens affect follicles differently at different maturity stages:

   • Most effective at preantral and antral stage

   • Length of androgen supplementation, therefore, counts

Androgens may be only/most effective in hypoandrogenic/DOR patients

Inhomogeneous study populations: PCOS as example