Recently, entrepreneur and longevity advocate Bryan Johnson made headlines by claiming that despite a biological age of 47, he has the “penis age” of a 22-year old. His assertion – based on the quantity, quality, and frequency of his nocturnal erections—sparked curiosity among men, leaving some to wonder about their own “penis age” and others questioning whether it even matters.
The concept of “penis age” is not medically recognized. Johnson arrived at his number by comparing his tracking results to his son’s. While it’s true that robust, regular spontaneous erections occurring during sleep (nocturnal penile tumescence- NPT) are more characteristic of youth, reducing this to an “age” label is more of a marketing hook than a medical diagnosis.
What Nighttime Erections Reveal About Your Health
Although the idea of “penis age” may be more buzz than science, paying attention to your nocturnal erections is worthwhile. These involuntary responses are more than a curiosity—they reflect important aspects of vascular, neurological, and hormonal health.
Here’s what your nighttime erection patterns can tell you:
- Vascular Health: Erections depend on strong blood flow. A decline in NPT can be an early warning sign of vascular problems such as atherosclerosis. In fact, erectile dysfunction often precedes heart disease by 2-5 years on average. And, chronic ED is associated with a 70% higher risk of premature death.
- Neurological Function: Erections depend on intact nerve pathways. During REM sleep if your neural circuits are disrupted – by spinal cord injury, neuropathy, or certain neurological disorders – NPT may be reduced or absent. The presence of normal nighttime erections is strong evidence that the penile nerves and erectile tissue are intact.
- Hormonal Status: Testosterone plays a critical role in spontaneous nighttime erections. A decline in NPT quality may indicate low testosterone levels or other hormonal imbalances. Since hormones like growth hormone and cortisol also influence sleep, disruptions in these systems can indirectly affect nocturnal erections.
Regular, quality nighttime erections generally signify that multiple body systems – circulatory, nervous, endocrine, and sleep regulation – are working well in concert. This is why nocturnal erections are considered an indicator of a man’s overall health. However, there are limitations to nighttime erections as a health barometer.
Understanding the Limits of Nighttime Erections
While tracking nighttime erections can provide valuable health insights, it’s important to recognize their limitations as a diagnostic tool:
- Natural Variability – NPT patterns can fluctuate due to stress, fatigue, alcohol intake, or random variation. Even with advanced wearable technology, consistent tracking is very uncommon.
- Sleep Quality Matters – Since nocturnal erections are linked to REM sleep, anything that disrupts sleep can also affect NPT frequency and quality.
- Context is Key – What’s considered “normal” varies by age. “Penis Age” results that would be considered robust for a man in his 70s could be a big red flag for someone.
The Bottom Line
While nighttime erections do correlate with many aspects of health and their absence can be a serious warning sign, measurements that led to Bryan Johnson’s penis age are only one piece of the puzzle. If you have noticed a significant changes in your nighttime erections or are experience consistent difficulties, it’s worth having a conversation with your doctor. Erectile changes can be an early signal of underlying health concerns, and proactive care is key to maintaining long-term vitality.