A recent study came out that essentially sent the message that Viagra was just as powerful as HRT (testosterone therapy) in several key areas. I covered this study and some more by the same researcher in my page on Does Testosterone Therapy Even Work?? Essentially what this researcher has been trying to show is that you can give a man Viagra and see him improve in erectile function and mood and then, when you add HRT on top of it, you get no additional improvement. The conclusion that the comes to is that HRT is, therefore, not really necessary and is an unneeded solution for most men.
However, let me give you 10 Reasons That Testosterone Therapy Will Usually Beat Out Viagra 24/7 365 (for men with low testosterone of course):
1. Venous Leakage. Penis tissues need testosterone and, when your testosterone gets low enough, the insides of your penis will literally start to wither. Connective tissue and nerves begin to atrophy. This can make it hard to close off an erection which means that as much blood leaks out of the penis as is getting pumped in, a condition I discuss in my link called Venous Leakage 101. Usually, HRT can partially or totally reverse this condition and, of course, the reason is that a fresh supply of testosterone literally brings the penis back to life and restores normal function. Now Viagra (and Cialis / Levitra) can help with this indirectly: they work by creating extra penile pressure, thus helping somewhat with the sealing off process. But clearly, this is a workaround solution and not getting at the root cause.
2. Insulin Sensitivity. A big percentage of males in the West have insulin resistance (prediabetes) and the suite of symptoms that usually accompany it called Metabolic Syndrome. Low testosterone actually accelerates Metabolic Syndrome and prediabetes by raising insulin levels and increasing insulin resistance. Furthermore, giving a low T guy testosterone will always lower his insulin levels. This effect is so powerful that at the HRT clinic I am going to they have been able to get virtually every Type II diabetic completely off of insulin. You can read about this more in my page on Testosterone and Diabetes. Taking Viagra or Cialis will have little impact in this area.
3. Decreased Hardening of the Arteries. Men who go on anti-androgens (for prostate cancer) have many nasty cardiovascular changes and one of them is an increase in arterial stiffness.  Furthermore, a study on dialysis patients showed a strong correlation between arterial stiffness and testosterone levels.  And, finally, giving men testosterone has been shown to actually reverse this arterial stiffness in large part or even totally in some cases.  There have been a couple of studies - and this is all quite controversial and discussed quite a bit on the Peak Testosterone Forum - that have shown that HRT increases cardiovascular risk. This makes no sense considering that testosterone has such a positive effect on arterial stiffness. How can you make arteries more stiff and improve CVD outcomes? However, for more information, see my page on The New Testosterone (HRT) Class Action Lawsuits.
NOTE: Testosterone therapy and Viagra / Cialis can work synergistically. Anything that gets a man to have more sexual intercourse will lead to increase baseline testosterone. And raising testosterone activates the enzyme (eNOS) that controls nitric oxide. So PDE5 Inhibitors can help testosterone and vice versa.
4. Decreases Arterial Inflammation. We need more study work on this, but there is research showing that testosterone seems to affect all the major players in this category, including IL-6, TNF-alpha, adiponectin and CRP. I cover this in my page on Testosterone and Inflammation. Again, it makes it very difficult to argue that low testosterone is healthy when it creates a pro-inflammatory environment.
5. Brain Health. One of the reasons that testosterone is so successful in my opinion is that it is so good for the male brain. Testosterone (and the ensuing rise in estradiol) increases dopamine and other critical neurotransmitters, something I document in my link on Testosterone and the Brain. On a practical level, this is extremely important. Low testosterone has been shown to disturb sleep and it is very often associated with anxiety, depression and fatigue.
Now the researcher mentioned above tried to challenge the use of HRT by noting that Viagra can improve mood just as much as HRT. Now, while it is true that Viagra can improve mood and various psychological parameters - nitric oxide improves blood flow to the brain and is a neurotransmitter in its own right: there simply is no substitute for testosterone. Working memory can be negatively impacted in a low testosterone man. Researchers also found that exercise has such a profoundly positive effect on the brain through it's increase of cerebral testosterone and that it can actually spawn neurogenesis. So it is very naive thinking to assume that by just popping a PDE5 inhibitor that you can solve a man's low T brain-related issues.
Did you know you can inexpensively do your own testing for most hormones? The industry leader is Discounted Labs..
6. Natural. Many men and physicians feel that HRT is "unnatural." To them it seems on par with taking steroids and feels like "cheating." Some even think that it is just an excuse to try to jack up one's waning sex life and/or muscle mass. The same crowd would tend to feel that Viagra is a much less invasive and non-aggressive solution to a male's problems. However, I would argue the opposite: testosterone is actually one of the most natural male substances and is bsolutely critical for a man's health.
Would you replace your thyroid hormones if you were hypothyroid? Sure. Would you replace your CoQ10 levels if they were low? Sure. What if you were deficient in Vitamin D? Same thing. So why not replace testosterone in the same way to more youthful levels?
And remember: many forms of HRT actually administrer bioidentical testosterone. Although injectibles such as testosterone cypionate and enanthate require a simple ester chain to be broken off, this a very simple process for your body to do and one is left, again with bioidentical testosterone afterwards. So, essentially, all the major forms of testosterone are delivering bioidentical or extremely close-to-identical bioidentical and natural testosterone into your system. Speaking as a guy who was just miserable with low testosterone for decades and whose life was completely turned around from HRT, I can assure you that HRT has no comparison with taking steroids and I had no motivations to put on muscle or anything similar. I just wanted to feel human again.
7. Osteropenia and Osteoporosis. A man's estradiol comes from the conversion of some of his testosterone via the aromatase enzyme. Surprisingly, many men have such low testosterone that they simply cannot build up enough estradiol to maintain their bone mass. If your estradiol is below 15-20 pg/ml, then this is probably something to discuss with your doctor. See my page on Testosterone and Bone Mass for details.
CONCLUSION: This list could actually go on and on, but I believe I have painted an adquate picture here. Testosterone is simply too critical to just ignore and pop a PDE5 inhibitor. Basically, the above researcher is attacking testosterone therapy by going after the easy stuff. He knows that Viagra cannot help with osteoporosis. He knows that Viagra cannot reverse someone's diabetes. And he knows that Viagra cannot heal venous leakage or hardening of the arteries. So, in my opinion, he likely picked the one or two areas where Viagra excels and then used it to build an anti-HRT storyline.
I can only say that those who suggest this have clearly never had to suffer with low testosterone or experiencedits nasty side effects. I was just miserable during my low testosterone days and will only go back kicking and screaming - let me tell you. You can read about it in My Personal Health Story.
Furthermore, ignoring low T can actually be a very dangerous philophophy and could get some men hurt. Why? Because low testosterone increases your risk factors for so many diseases! This is the subject of my book Low Testosterone By The Numbers, which discusses how a man whose testosterone is between 250 and 400 ng/dl is at increased risk for all the conditions above.
Again, Viagra and Cialis have their place for some men, especially in the short term in low dosages. But to suggest that they can be a replacement for the very low hormone levels seen in the typical hypogonadal male is very risky in my opinion.
1) Baylor College of Medicine, "Men with low testosterone, erectile dysfunction may improve sexual function with testosterone gels"
2) Clinical Science, 2003, 104:(195 201), "Testosterone suppression in men with prostate cancer leads to an increase in arterial stiffness and hyperinsulinaemia"
3) Eur J Endocrinol, May 1 2009, 160:839-846, "Effect of testosterone replacement therapy on arterial stiffness in older hypogonadal men"