**Evaluated by Denise Asafu-Adjei, M.D., MPH**
—
### A few years ago, PN co-founder John Berardi, PhD, shared a shirtless image of himself on his 47th birthday.
He referred to it as his “anti-regress pic” and expressed gratitude for 30 years of squats, deadlifts, presses, and chin-ups—among other workouts—for his defined six-pack, sculpted chest, and impressive biceps.
The question many commenters asked:
**“Are you on testosterone?”**
Dr. Berardi clarified in a subsequent post that, while he supported testosterone replacement therapy (TRT) for those who require it, he personally was not undergoing this treatment, and his testosterone levels were consistently “normal.” He also shared [some thought-provoking insights regarding testosterone and aging.](https://www.instagram.com/p/CSEc8VKssY8/) Dr. Berardi’s perspective contrasts sharply with the typical narrative heard these days when…
– The prevailing view seems to suggest that decreasing testosterone is indicative of aging, weakness, and impotence—not to mention a risk to masculinity.
– More and more middle-aged men are opting out of conventional medical examinations in favor of men-focused telehealth platforms that cater to testosterone enhancement.¹
– [Reddit groups](https://www.reddit.com/r/HubermanLab/comments/144397e/testosterone_optimization/) have emerged solely to fixate on neuroscientist Andrew Huberman’s supplement guidelines for optimizing testosterone.
– Media outlets churn out article after article about “testosterone-boosting” foods to consume and “testosterone-lowering” foods to steer clear of.
Whether you’re a coach answering the “How do I optimize testosterone?” query from clients—or simply a regular guy aiming to age gracefully—it’s easy to feel overwhelmed and perplexed by the contradictory information.
Are declining testosterone levels typical?
Do testosterone-enhancing supplement regimens genuinely yield results?
Who gains from testosterone therapy—and who does not?
In this article, we will investigate those inquiries and more.
## What is testosterone?
Produced by the testes, testosterone is the sex hormone accountable for male sexual traits such as prominent muscles, deep voices, and hairy chests. It acts as a chemical messenger that is vital for various functions within the body, including sperm production and maintaining bone density.
(In women, who also require testosterone for various bodily functions, it is produced by the ovaries and adrenal glands. Their bodies generate much less of it—around 10 to 20 times less than men.)
Possibly due to its connection with muscle development and libido, many cisgender men perceive testosterone in binary terms, with lower levels being negative and higher levels being positive.
However, **it’s more accurate to perceive the relationship between testosterone and health as a spectrum** that ranges from too low (problematic) to too high (also problematic), with the healthy range residing in between these two extremes, according to Denise Asafu-Adjei, MD, MPH, urologist, men’s health authority, and assistant professor of urology at Loyola University Chicago-Stritch School of Medicine.
As illustrated in the chart below, the hazards linked to exceedingly low testosterone are comparable to the dangers of excessively high levels (generally only attainable through anabolic steroid use).
| **Issues related to extremely LOW testosterone** | **Issues related to extremely HIGH testosterone** |
|————————————————–|—————————————————|
| – Brittle bones | – Blood clots |
| – Decreased body and facial hair | – Heart damage |
| – Muscle mass loss | – Elevated blood pressure |
| – Low libido (sexual desire) | – Atrophied testicles |
| – Atrophied testicles | – Reduced sperm count |
| – Erectile dysfunction | – Enlarged prostate |
| – Reduced sperm count | – Acne |
| – Gynecomastia (increased breast tissue) | – Fluid retention |
| – Irritability | – Increased appetite |
| – Poor focus | – Insomnia |
| – Fatigue | – Headaches |
| – Depression | – Irritability |
| | – Mood swings |
| | – Impaired judgment |
### Low testosterone vs. *lower* testosterone
Testosterone levels naturally decline with age, with most men experiencing about a 1 to 2 percent reduction annually starting around age 40. By age 75, most men have approximately 30 percent less of the hormone than they possessed at age 25.²
(Interesting tidbit: Between the ages of 25 and 80, men can anticipate their testicles to shrink by 15 percent.³)
**Nevertheless, age-related declines in testosterone are not synonymous with “low testosterone.”**
**Hypogonadism** is the medical term denoting low testosterone levels, and