TRT: Your Complete Guide to Safe Dosing, Risks, and Boosting Longevity

**Dr. Gabrielle Lyon** (0:00)
What is the role of testosterone and erectile function?

**Dr. Tobias Kohler** (0:03)
If testosterone is very low, then penis ain't gonna work.

**Dr. Abraham Morgentaler** (0:07)
Testosterone is a brain hormone. Yes, it also works on muscle and fat and all these other organs, but it's a brain hormone.

**Dr. Mohit Khera** (0:17)
We were taught in medical school this concept called male menopause.

**Dr. Gabrielle Lyon** (0:21)
Andropause doesn't exist.

**Dr. Mohit Khera** (0:22)
It doesn't exist.

**Dr. Gabrielle Lyon** (0:23)
I know.

**Dr. Mohit Khera** (0:23)
As men get older, aging alone doesn't drop their testosterone level. It's the acquisition of co-morbid conditions that drops their level.

**Dr. Gabrielle Lyon** (0:33)
I remember I was listening to someone speak and they were talking about how everyone should be on testosterone. What if an individual has normal testosterone levels? That individual is listening to an influencer. They go on testosterone and they shut down their fertility forever. In order to conceive, they're going to have to go get sperm extracted from their testicles with a needle or something?

**Dr. Mohit Khera** (0:52)
Not fun. 90% of testosterone in men is made from the testicles. There's a signal from the brain which goes to the testicles and says, come on, let's make testosterone. If someone has low testosterone, there's only two areas the problem can be, from the brain or from the testicles.

**Dr. Gabrielle Lyon** (1:07)
People were 100% sure that testosterone replacement therapy was going to give people prostate cancer. And you challenged that notion. I would love to hear that back story.

**Dr. Abraham Morgentaler** (1:16)
Oh my god, so...

**Dr. Gabrielle Lyon** (1:24)
Let's define testosterone deficiency in terms of numbers and when one could consider treatment.

**Dr. Abraham Morgentaler** (1:33)
Yeah, good. So, in some ways, testosterone is... The men who really need it don't get treated, not enough of them. And a lot of the men who don't need testosterone are getting it. That people should be treated if they have low levels of testosterone, they have either symptoms or what we call signs. Symptoms are things that people experience, like my sex drive is down, signs are something you can measure, like their hematocrit, their red blood cell count is reduced, or their bone density is down, something you can measure. So, traditionally, all the guidelines say you should have both. The challenge is, what's a low level of testosterone? So, and critics of testosterone therapy say, the experts can't even agree on what a low level is, and that's true, and that's true.
And part of it is that some of the decisions about what a low level is has been arbitrary. So, you know, the FDA uses a number below 300 nanograms per deciliter. And if you look at any of their writing, they have no citations for that. There's no reference that says where they got that number from. So, the urban myth that I think is true is, based on talking to people, is that when there was a first new testosterone product brought to the FDA in the late 1998, I think, it was a patch, the FDA said, well, you have a drug that's supposed to normalize testosterone. Please tell us what a low level is. Fair.

**Dr. Gabrielle Lyon** (3:02)
I think that's totally fair.

**Dr. Abraham Morgentaler** (3:04)
And so they had a very senior expert, and he said, well, people disagree on the number, but some people think it should be 400, some say 350, some say 250

**Dr. Gabrielle Lyon** (3:12)
And free testosterone was not discussed?

**Dr. Abraham Morgentaler** (3:14)
Nobody's talked about it. We have to talk about free testosterone, but nobody's, that hasn't been part of the conversation for forever. But, and so this guy said, apparently, to the FDA, I think 300 is a fair number.

**Dr. Gabrielle Lyon** (3:27)
But not defined on age. So Matt, my producer, could have 300, and my dad Nate could have 300, and let's say it's 310 for both of them.

**Dr. Abraham Morgentaler** (3:36)
Right.

**Dr. Gabrielle Lyon** (3:37)
Could we treat them?

**Dr. Abraham Morgentaler** (3:39)
Well, of course you can if they have symptoms, in my opinion. The idea that there's a, first of all, the idea that there's a single number that separates everybody is just, it's anti-scientific, right? Like we're not like, we don't work like that. Our bodies are not, we're not clones of each other, right? You do research in animals, like rats, they're all the same genetic strain. They're all basically identical twins. That's not true for humans. And we all have different set points for a lot of different things. People can tolerate cold, heat, pain. Like we're all different with all these things. And true also for when people become symptomatic in terms of having low levels of testosterone. But it's worse than that. It's worse than that because what a low number is, is defined by specialty and by geography. So the endocrine...