Tell them to review the Finasteride studies section:
viewforum.php?f=8
Forward them copies of Dr. Traish and Dr. Irwig’s papers.
onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2011.02255.x/abstract
onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2010.02157.x/abstract
onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2012.02846.x/abstract
Note comments by other professionals dealing with the issue:
Dr. Alan Jacobs
blog.alanjacobsmd.com/alan-jacobs-mds-blog/2010/04/a-neuroendocrine-approach-to-finasteride-side-effects-in-men.html
blog.alanjacobsmd.com/alan-jacobs-mds-blog/2010/06/the-plot-thickens-along-with-the-hair-when-you-mess-with-dihydrotestosterone.html
blog.alanjacobsmd.com/alan-jacobs-mds-blog/2010/06/a-proposed-mechanism-for-prolonged-sexual-side-effects-from-finasteride.html
Dr. Irwig:
"Further valuable research could determine who would be susceptible to finasteride through genetic studies of polymorphisms of 5a reductase and the androgen receptor. "
Dr. Crisler:
viewtopic.php?f=27&t=6746&p=58832&hilit=crisler+resistance#p58832
viewtopic.php?f=22&t=2551
The below is on homepage of Propeciahelp.com
Dr. Traish:
"In a 2011 study review in the Journal of Sexual Medicine, lead researcher Abdulmaged Traish, Ph.D., and his colleagues outlined extensive cause for concern. They concluded that animal and human studies strongly suggest that finasteride isn’t limited to its target tissues but in fact can reduce DHT in many tissues, potentially affecting not only nerve-signaling pathways in the penis but also the ratio of male-to-female hormone levels circulating through a user’s body. One study Traish cites found that men taking 1 milligram of finasteride daily had significantly higher levels of estradiol—the predominant female sex hormone—than men taking a placebo. Just as worrisome as the possible effects in body tissue is the growing evidence that finasteride can enter a man’s brain and disrupt key chemicals therein.
As Traish’s study review details, once finasteride reaches brain tissue it affects the production of more hormones than just DHT. At particular risk, Traish believes, are neurosteroids—brain chemicals that play a role in reducing anxiety, enhancing memory, regrowing brain cells, and helping us sleep.
There’s yet another issue for men who already find themselves battling feelings of despair over their dissipated sex lives: At least two studies have shown that finasteride may cause the onset of depressive symptoms. And last year, researchers in Germany found that the drug inhibits the growth of new neurons in the brain’s hippocampus ; this type of neurological “failure to thrive” has also been documented in people who suffer from clinical depression.
“The percentage of affected men may be small,” acknowledges Traish, a researcher in the biochemistry and urology departments at Boston University’s school of medicine, “but our research definitely concludes that PFS is real. For a subset of these men, the damage persists—maybe forever—even after they go off the drug. We don’t fully understand why, but it is as if something shuts off biologically, and stays that way.”
Dr. Goldstein:
“At the end of the day, because sex steroid hormones are critical for genital organ structure and function, depriving young men of a critical sex steroid — dihydrotestosterone — affects sexual function.”
"… The 5 alpha reductase enzyme ALSO metabolizes progesterone to 5 alpha-dihydroprogesterone and deoxycorticosterone to 5 alpha-dihydrodeoxycorticosterone. And in the brain, the products of 5 alpha reductase inhibitors are transformed by another group of specific enzymes known as 3 alpha-hydroxysteroid dehydrogenases, which reduces 5 alpha-dihydrotestosterone to 3 alpha, 5 alpha-androstane 17b-diol (3a-diol), and 5 alpha-dihydroprogesterone to 3 alpha, 5 alpha-tetrahydroprogesterone (allopregnanolone). Similarly, 5 alpha-dihydrodeoxycorticosterone is further reduced to 3 alpha, 5 alpha-tetrahydrodeoxycorticosterone. " [THDOC]
"Theoretically, these important neurosteroid derivatives are UNNECESSARILY LOWERED (collateral damage) by 5 alpha reductase inhibitors for hair loss. These reduced important neurosteroid derivatives are thought to function in the central nervous system with important physiological functions including modulation of gamma aminobutyric acid type A receptor, sigma receptor function, nicotinic acetylcholine receptor, voltage gated calcium channels, and synaptic and brain plasticity.
“To translate into clinical terms, these physiological functions may impact mood, rhythm, stress, sleep, memory, anxiety, and sexual function.”