I’m not sure one can justify mandating coverage for Viagra or contraceptives or abortifacients from a secular standpoint. They increase the cost of insurance for everyone, but not to save lives or improve health. They are all manipulations of the normal functions of the human body, (which includes aging in the case of Viagra, and aging is normal) using medically-tested chemicals to do it, and in a medical setting. And both are designed to enhance totally voluntary activity. Disease is not voluntary. It imposes itself. So, to the extent scarce resources are used to enhance voluntary activity, they reduce resources for things that really do save lives or improve health, for conditions that are not voluntary.
It seems to me, then, that if a man wants Viagra, he ought to pay for it, 100%. If a woman wants to have sex without conception, she should pay for that 100% as well. If, by doing that, the overall cost of insurance goes down by any amount, a secular purpose is served, which is increasing resources available for things that really do save lives or improve health, and which people otherwise cannot, themselves, control.
What all of this healthcare debate does not seem to take into account is the fact that resources for healthcare, as with all other good things, are limited. As a consequence of our seeming refusal to accept the fact that resources are limited, we find ever greater portions of national income going to debt service, thus reducing limited resources even more.