Everything you've absorbed about aging and sex comes from two equally useless sources: jokes about old men, and supplement ads promising you'll perform "like you're 25 again." The actual longitudinal data tells a much more interesting story — including one finding that might literally save your life.
The backbone of what medicine knows here is the Massachusetts Male Aging Study (MMAS) — a random-sample survey of over 1,700 men aged 40 to 70, first assessed in 1987–89 and re-interviewed roughly a decade later, published across the Journal of Urology and related journals. It remains the most-cited population dataset on male sexual aging.
Sit with the flip side of that number, because nobody ever quotes it: at 70 years old, 85% of men do not have complete erectile dysfunction. The famous companion statistic — that 52% of men aged 40–70 have "some degree" of ED — lumps together minimal, moderate, and complete cases. Some change with age is nearly universal. Total shutdown is not, at any age in the dataset.
AGE 20–29
Vascular function, testosterone, and nocturnal erection frequency are all at their lifetime peak, and stopwatch data shows men aged 18–30 have the longest median time to ejaculation of any age group — 6.5 minutes, per Waldinger's five-country study. The stereotype that young men have the least control is backwards; the full numbers on that are here.
The asterisk: erection problems in your 20s are more common than the "peak decade" framing suggests — driven overwhelmingly by anxiety, alcohol, and lifestyle rather than plumbing. That has its own dedicated article. One MMAS finding worth planting now, though: in men followed prospectively, smoking at baseline nearly doubled the rate of moderate-to-complete ED at follow-up (24% vs. 14%). The decisions of your 20s are compounding interest, in both directions.
AGE 30–39
Functionally, very little changes for most men in their 30s. Longitudinal aging studies document a slow, gradual decline in average testosterone beginning around this decade — but the decline is measured in small percentages per year, and for most men it stays comfortably within the normal range for decades. A 35-year-old with genuinely low testosterone symptoms has a medical question worth asking, not an inevitable aging story.
What does start mattering in the 30s is the accumulation: blood pressure, weight, sleep, alcohol, and medications — including SSRIs and blood-pressure drugs — quietly become the biggest variables in sexual function. The penis is a vascular organ. Everything that affects your arteries affects it.
AGE 40–49
This is where MMAS data begins, and where the single most important fact in this article lives.
New cases of ED in the MMAS cohort ran at about 12.4 per 1,000 man-years in the 40s — real, but uncommon. What matters is what new-onset ED in this decade means. Penile arteries are 1–2 mm wide; coronary arteries are 3–4 mm. When systemic arterial disease develops, the smallest pipes clog first. Cardiology reviews formalized this as the "artery size hypothesis" (Montorsi et al.), and the clinical literature is consistent on the timeline:
Across multiple studies and reviews, erectile dysfunction precedes symptomatic coronary artery disease by roughly 2–3 years and precedes cardiovascular events (heart attack, stroke) by roughly 3–5 years. In a landmark analysis of over 9,400 men (Thompson et al., JAMA 2005), developing ED carried a subsequent cardiovascular risk in the same range as being a current smoker or having a family history of heart attack. New, persistent ED in your 40s or 50s — especially without an obvious psychological trigger — is a reason to see a doctor about your heart, not just your erections.
This reframes the entire topic. Erection changes in midlife aren't an embarrassing failure to hide from your doctor — they're one of the few early, visible signals your cardiovascular system ever sends. Men who act on it get a 3-to-5-year head start on the most preventable major disease there is. A meta-analysis of roughly 155,000 men (Zhao et al.) found ED was associated with a 59% higher risk of coronary heart disease and 34% higher risk of stroke. Use the signal.
AGE 50–59
New ED cases roughly double versus the 40s (29.8 per 1,000 man-years in MMAS). Refractory periods — the reload time between orgasms — lengthen noticeably for most men; the biology of that is here. Erections tend to need more direct physical stimulation and rely less on spontaneous visual arousal. None of this is dysfunction; it's a change in operating manual.
The word "optional" in the heading is doing real work, though. The MMAS risk factors for ED — diabetes, hypertension, heart disease, smoking — are heavily lifestyle-mediated. Two men at 55 can have wildly different function, and the difference is usually written in their arteries, not their birthdays. Interestingly, the one thing that does not decline: ejaculation speed. Waldinger's data shows median latency decreases with age (4.3 minutes past 51, vs. 6.5 in young men) — a second popular myth pointing the wrong direction.
AGE 60–79
ED incidence continues climbing (46.4 per 1,000 man-years for ages 60–69 in MMAS), and cardiology reviews estimate about 1 in 3 men over 70 have clinically significant ED. Morning erections become less frequent — their diagnostic value matters more than ever, since their complete disappearance is a vascular data point worth mentioning to a doctor. Orgasm intensity and ejaculate volume typically decrease. Testicles sit lower; skin elasticity changes the flaccid appearance.
And yet: two out of three men over 70 don't have significant ED, 85% never reach complete ED, and treatment options at this age are the same evidence-based menu available at 45 — most of them highly effective. The stereotype of automatic shutdown past retirement age has no support in the population data.
"Erectile dysfunction is just part of getting old. Nothing to do but accept it."
ED at every age is dominated by treatable vascular and psychological factors, not birthdays. Even at 70, complete ED affects only 15% of men — and new-onset ED at any age is a medical signal worth acting on, not a verdict to accept.
| Function | What the data shows with age | Source |
|---|---|---|
| Complete ED | 5% at 40 → 15% at 70 | MMAS, J Urol 1994 |
| Any degree of ED | 52% of men 40–70 combined | MMAS, J Urol 1994 |
| New ED cases per year | ~1.2% (40s) → ~3% (50s) → ~4.6% (60s) | MMAS, J Urol 2000 |
| Time to ejaculation | Decreases: 6.5 min (18–30) → 4.3 min (51+) | Waldinger, J Sex Med 2005 |
| Refractory period | Lengthens substantially | See refractory period article |
| Smoking effect on ED risk | Nearly doubled (24% vs 14%) prospectively | MMAS, Prev Med 2000 |
The penis ages at the speed of your arteries, not the speed of the calendar — which means the decade-by-decade story is substantially yours to write, and when it does send a warning signal, it sends it years before your heart does.
Percentiles from 15,521 clinically measured men — no aging myths, just the data.
Check Your PercentilesAging changes sexual function gradually, unevenly, and far less totally than the culture assumes. The stopwatch runs slightly faster with age, not slower. The refractory period lengthens. Erections shift from automatic to manual transmission. And the single most valuable thing to know is the warning-light principle: new erectile trouble in midlife predicts cardiovascular events 3–5 years out, with risk comparable to smoking. The men who mention it to a doctor early aren't just fixing their sex lives — they're catching heart disease in the window where it's most fixable.
Whatever decade you're in, the two moves that hold up across the entire dataset are the same: protect your arteries, and treat changes as information rather than shame. If something has changed and it bothers you — or even if it doesn't — that's a routine conversation for any doctor, and here's exactly how to start it.