How do sexual function, erectile quality, and penile tissue change in older adulthood?

1. What studies actually measure — and what they find

Population and longitudinal studies repeatedly report that sexual desire, frequency of orgasm, and frequency of intercourse decline with age, although arousal may show more variable results depending on study methods; longitudinal work shows declines become more pronounced with increasing age in men and mixed but generally declining trends in women through menopause and later life ^{[1] [7] [8]}. Epidemiology of ED is strongly age‑dependent: combined moderate-to-complete ED prevalence rises sharply from middle age into older adulthood (about 22% at 40 to ~49% by age 70 in some datasets) ^{[3] [9]}.

2. Mechanisms underpinning functional change: hormones, vascular health, and nerves

Researchers link declines in sexual functioning to hormonal shifts (e.g., lower testosterone in men, estrogen deficiency after menopause in women), systemic health problems (cardiovascular disease, diabetes), and medications — all of which become more common with age and affect desire, arousal, lubrication, and erectile responses ^{[8] [10] [11]}. For men, ED often reflects vascular and endothelial problems of the cavernosal tissue; the penis functions as an extension of the peripheral vascular system, so age‑related vascular disease and nerve dysfunction degrade erectile performance ^{[4] [11]}.

3. What happens to penile tissue with age

Histologic and clinical studies describe age‑associated loss of cavernosal smooth muscle, replacement by fibrous tissue (fibrosis), decreased endothelial cell activity, and other connective‑tissue changes; these changes reduce the penis’s ability to trap blood and maintain rigidity, and contribute to conditions like venous leak (CVOD) and age‑related ED ^{[4] [5]}. Scar formation over years — and declining tissue repair — also raises the risk of Peyronie’s disease and curvature in older men ^[6].

4. Size, girth and the “shrinkage” question

Multiple clinical and lay sources note that a perceived reduction in penile length or girth with age is often due to vascular changes, collagen loss, fibrosis, increased suprapubic fat (burial), and reduced elasticity rather than a simple, uniform atrophy of the organ; some accounts also describe “disuse atrophy” or the visual effect of fat pads as contributors ^{[12] [13] [14]}. Evidence cited in guideline discussions and reviews suggests vascular and hormonal processes are likely drivers but exact, generalizable magnitude of change is not uniformly quantified across the available sources ^{[15] [12]}.

5. Clinical and quality‑of‑life context: not inevitable, often treatable

Authors emphasize that age‑related sexual changes do not make sexual relationships impossible — many older adults remain sexually active — and that ED is not simply “normal aging” but often treatable and associated with modifiable risk factors (exercise, smoking cessation, treating diabetes/hypertension) and therapies (PDE5 inhibitors, devices, surgery, newer interventions discussed in the literature) ^{[10] [16] [17]}. At the same time, prevalence projections underscore a large and growing burden of ED that health systems must address (projected global ED cases referenced from MMAS‑based estimates) ^{[18] [19]}.

6. Competing perspectives and limitations in reporting

Some reviews and clinical sources stress that declines are mediated largely by comorbid illness, medications and psychosocial factors (implying aging per se is not the sole cause), while epidemiologic reports show strong age correlations that cannot be ignored — both views are present in the literature ^{[10] [3]}. Available sources do not specify precise, universally applicable magnitudes of penile tissue shrinkage or average percent loss in erectile quality across all men; estimates vary by cohort and methodology ^{[15] [14]}.

7. Practical takeaways for readers

If sexual changes cause distress or impact relationships, clinicians recommend evaluation because many contributors (cardiovascular disease, diabetes, low hormones, medications, treatable penile conditions) can be identified and in many cases improved with lifestyle change, medical therapy, or procedures ^{[11] [2]}. For women, attention to lubrication, hormone status, and relationship/psychological factors is likewise essential ^{[8] [2]}.

Limitations: reporting across sources mixes population surveys, clinical reviews and lay summaries; differences in methods and definitions mean specific numeric estimates vary between studies and projections ^{[1] [18]}.