Erectile dysfunction

Signs and symptoms

ED is characterized by the persistent or recurring inability to achieve or maintain an erection of the penis with sufficient rigidity and duration for satisfactory sexual activity. It is defined as the "persistent or recurrent inability to achieve and maintain a penile erection of sufficient rigidity to permit satisfactory sexual activity for at least 3 months."

Psychological impact

ED often has an impact on the emotional well-being of both males and their partners. Many males do not seek treatment due to feelings of embarrassment. About 75% of diagnosed cases of ED go untreated.

Causes

Causes of or contributors to ED include the following:

• Diets high in saturated fat are linked to heart diseases, and males with heart diseases are more likely to experience ED. By contrast, plant-based diets show a lower risk for ED.
• Prescription drugs (e.g., SSRIs, beta blockers, antihistamines, alpha-2 adrenergic receptor agonists, thiazides, hormone modulators, and 5α-reductase inhibitors)
• Neurogenic disorders (e.g., diabetic neuropathy, temporal lobe epilepsy, multiple sclerosis, Parkinson's disease, multiple system atrophy)
• Cavernosal disorders (e.g., Peyronie's disease)
• Hyperprolactinemia (e.g., due to a prolactinoma)
• Psychological causes: performance anxiety, stress, and mental disorders
• Surgery (e.g., radical prostatectomy)
• Ageing: after age 40 years, ageing itself is a risk factor for ED, although numerous other pathologies that may occur with ageing, such as testosterone deficiency, cardiovascular diseases, or diabetes, among others, appear to have interacting effects
• Kidney disease: ED and chronic kidney disease have pathological mechanisms in common, including vascular and hormonal dysfunction, and may share other comorbidities, such as hypertension and diabetes mellitus that can contribute to ED
• Lifestyle habits, particularly smoking, which is a key risk factor for ED as it promotes arterial narrowing. Due to its propensity for causing detumescence and erectile dysfunction, some studies have described tobacco as an anaphrodisiacal substance.
• COVID-19: preliminary research indicates that COVID-19 viral infection may affect sexual and reproductive health. Surgical intervention for a number of conditions may remove anatomical structures necessary to erection, damage nerves, or impair blood supply.

ED can also be associated with bicycling due to both neurological and vascular problems due to compression. The increased risk appears to be about 1.7-fold.

Concerns that use of pornography can cause ED have little support in epidemiological studies, according to a 2015 literature review. According to Gunter de Win, a Belgian professor and sex researcher, "Put simply, respondents who watch 60 minutes a week and think they're addicted were more likely to report sexual dysfunction than those who watch a care-free 160 minutes weekly." A 2026 review shows that simple pornography consumption does not cause erectile dysfunction, the relationship between pornography and ED being much more complex.

In seemingly rare cases, medications such as SSRIs, isotretinoin (Accutane) and finasteride (Propecia) are reported to induce long-lasting iatrogenic disorders characterized by sexual dysfunction symptoms, including erectile dysfunction in males; these disorders are known as post-SSRI sexual dysfunction (PSSD), post-retinoid sexual dysfunction/post-Accutane syndrome (PRSD/PAS), and post-finasteride syndrome (PFS). These conditions remain poorly understood and lack effective treatments, although they have been suggested to share a common etiology.

• Rarely impotence can be caused by aromatase being active. See Androgen replacement therapy.

Pathophysiology

Penile erection is managed by two mechanisms: the reflex erection, which is achieved by directly touching the penile shaft, and the psychogenic erection, which is achieved by erotic or emotional stimuli. The former involves the peripheral nerves and the lower parts of the spinal cord, whereas the latter involves the limbic system of the brain. In both cases, an intact neural system is required for a successful and complete erection. Stimulation of the penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of the smooth muscles of the corpora cavernosa (the main erectile tissue of the penis), and subsequently penile erection. Additionally, adequate levels of testosterone (produced by the testes) and an intact pituitary gland are required for the development of a healthy erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems.

Diagnosis

In many cases, the diagnosis can be made based on the person's history of symptoms. In other cases, a physical examination and laboratory investigations are done to rule out more serious causes such as hypogonadism or prolactinoma.

One of the first steps is to distinguish between physiological and psychological ED. Determining whether involuntary erections are present is important in eliminating the possibility of psychogenic causes for ED. Obtaining full erections occasionally, such as nocturnal penile tumescence when asleep (that is, when the mind and psychological issues, if any, are less present), tends to suggest that the physical structures are functionally working. Similarly, performance with manual stimulation, as well as any performance anxiety or acute situational ED, may indicate a psychogenic component to ED.

Another factor leading to ED is diabetes mellitus, a well known cause of neuropathy. ED is also related to generally poor physical health, poor dietary habits, obesity, and most specifically cardiovascular disease, such as coronary artery disease and peripheral vascular disease. Screening for cardiovascular risk factors, such as smoking, dyslipidemia, hypertension, and alcoholism, is helpful.

In some cases, the simple search for a previously undetected groin hernia can prove useful since it can affect sexual functions in males and is relatively easily curable.

The currentedition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) lists Erectile Disorder (ICD-10-CM code: F52.21) as a diagnosis. According to the DSM, it "is the more specific DSM-5 diagnostic category in which erectile dysfunction persists for at least 6 months and causes distress in the individual." The ICD-10, to which the DSM refers regarding Erectile dysfunction, lists it under Failure of genital response (F52.2). The latest edition of the ICDnamely, the ICD-11lists the condition as Male erectile dysfunction (HA01.1).

Ultrasonography

Penile ultrasonography with doppler can be used to examine the erect penis. Most cases of ED of organic causes are related to changes in blood flow in the corpora cavernosa, represented by occlusive artery disease (in which less blood is allowed to enter the penis), most often of atherosclerotic origin, or due to failure of the veno-occlusive mechanism (in which too much blood circulates back out of the penis). Before the Doppler sonogram, the penis should be examined in B mode, in order to identify possible tumors, fibrotic plaques, calcifications, or hematomas, and to evaluate the appearance of the cavernous arteries, which can be tortuous or atheromatous.

Erection can be induced by injecting 10–20 μg of prostaglandin E1, with evaluations of the arterial flow every five minutes for 25–30 min (see image). The use of prostaglandin E1 is contraindicated in patients with predisposition to priapism (e.g., those with sickle cell anemia), anatomical deformity of the penis, or penile implants. Phentolamine (2 mg) is often added. Visual and tactile stimulation produces better results. Some authors recommend the use of sildenafil by mouth to replace the injectable drugs in cases of contraindications, although the efficacy of such medication is controversial.

Before the injection of the chosen drug, the flow pattern is monophasic, with low systolic velocities and an absence of diastolic flow. After injection, systolic and diastolic peak velocities should increase, decreasing progressively with vein occlusion and becoming negative when the penis becomes rigid (see image below). The reference values vary across studies, ranging from 25 cm/s to 35 cm/s. Values above 35 cm/s indicate the absence of arterial disease, values below 25 cm/s indicate arterial insufficiency, and values of 25–35 cm/s are indeterminate because they are less specific (see image below). The data obtained should be correlated with the degree of erection observed. If the peak systolic velocities are normal, the final diastolic velocities should be evaluated, those above 5 cm/s being associated with venogenic ED.

File:Doppler ultrasonography of cavernous artery flow in flaccid and erected state.jpg|Graphs representing the color Doppler spectrum of the flow pattern of the cavernous arteries during the erection phases. A: Single-phase flow with minimal or absent diastole when the penis is flaccid. B: Increased systolic flow and reverse diastole 25 min after injection of prostaglandin. File:Doppler ultrasonography of cavernous arterial insufficiency.jpg|Longitudinal, ventral ultrasound of the penis, with pulsed mode and color Doppler. Flow of the cavernous arteries at 5, 15, and 25 min after prostaglandin injection (A, B, and C, respectively). The cavernous artery flow remains below the expected levels (at least 25–35 cm/s), which indicates ED due to arterial insufficiency.

Other workup methods

;Penile nerves function:Tests such as the bulbocavernosus reflex test are used to ascertain whether there is enough nerve sensation in the penis. The physician squeezes the glans (head) of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the latency between squeeze and contraction by observing the anal sphincter or by feeling it with a gloved finger in the anus.

;Nocturnal penile tumescence (NPT):It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge. A significant proportion of males who have no sexual dysfunction nonetheless do not have regular nocturnal erections.

;Penile biothesiometry:This test uses electromagnetic vibration to evaluate sensitivity and nerve function in the glans and shaft of the penis.

;Dynamic infusion cavernosometry (DICC):Technique in which fluid is pumped into the penis at a known rate and pressure. It gives a measurement of the vascular pressure in the corpus cavernosum during an erection.

;Corpus cavernosometry:Cavernosography measurement of the vascular pressure in the corpus cavernosum. Saline is infused under pressure into the corpus cavernosum with a butterfly needle, and the flow rate needed to maintain an erection indicates the degree of venous leakage. The leaking veins responsible may be visualized by infusing a mixture of saline and x-ray contrast medium and performing a cavernosogram. In Digital Subtraction Angiography (DSA), the images are acquired digitally.

;Magnetic resonance angiography (MRA): This is similar to magnetic resonance imaging. Magnetic resonance angiography uses magnetic fields and radio waves to provide detailed images of the blood vessels. The doctor may inject into the patient's bloodstream a contrast agent, which causes vascular tissues to stand out against other tissues, so that information about blood supply and vascular anomalies is easier to gather.

;Erection Hardness Score

Treatment

Treatment depends on the underlying cause. In general, exercise, particularly of the aerobic type, is effective for preventing ED during midlife.Wespes E (chair), et al. Guidelines on Male Sexual Dysfunction: Erectile dysfunction and premature ejaculation. European Association of Urology 2013 Counseling can be used if the underlying cause is psychological, including how to lower stress or anxiety related to sex. Medications by mouth and vacuum erection devices are first-line treatments, Treatments, other than surgery, do not fix the underlying physiological problem, but are used as needed before sex.

Medications

The PDE5 inhibitors sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) are prescription drugs which are taken by mouth. Additionally, a cream combining alprostadil with the permeation enhancer DDAIP has been approved in Canada as a first line treatment for ED. Penile injections, on the other hand, can involve one of the following medications: papaverine, phentolamine, and prostaglandin E1, also known as alprostadil. Medications to treat ED may cause a side effect called priapism.

Prevalence of medical diagnosis

In a study published in 2016, based on US health insurance claims data, out of 19,833,939 US males aged ≥18 years, only 1,108,842 (5.6%), were medically diagnosed with erectile dysfunction or on a PDE5I prescription (μ age 55.2 years, σ 11.2 years). Prevalence of diagnosis or prescription was the highest for age group 60–69 at 11.5%, lowest for age group 18–29 at 0.4%, and 2.1% for 30–39, 5.7% for 40–49, 10% for 50–59, 11% for 70–79, 4.6% for 80–89, 0.9% for ≥90, respectively.

Focused shockwave therapy

Focused shockwave therapy involves passing short, high frequency acoustic pulses through the skin and into the penis. These waves break down any plaques within the blood vessels, encourage the formation of new vessels, and stimulate repair and tissue regeneration.

Focused shockwave therapy appears to work best for males with vasculogenic ED, which is a blood vessel disorder that affects blood flow to tissue in the penis. The treatment is painless and has no known side effects. Treatment with shockwave therapy can lead to a significant improvement of the IIEF (International Index of Erectile Function).

Testosterone

Men with low levels of testosterone can experience ED. Taking testosterone may help maintain an erection. Males with type 2 diabetes are twice as likely to have lower levels of testosterone, and are three times more likely to experience ED than non-diabetic men.

Pumps

Main article: penis pump

A vacuum erection device helps draw blood into the penis by applying negative pressure. This type of device is sometimes referred to as penis pump and may be used just prior to sexual intercourse. Several types of FDA approved vacuum therapy devices are available under prescription. When pharmacological methods fail, a purpose-designed external vacuum pump can be used to attain erection, with a separate compression ring fitted to the base of the penis to maintain it. These pumps should be distinguished from other penis pumps (supplied without compression rings) which, rather than being used for temporary treatment of impotence, are claimed to increase penis length if used frequently, or vibrate as an aid to masturbation. More drastically, inflatable or rigid penile implants may be fitted surgically.

Vibrators

Main article: Vibrator (sex toy)

The vibrator was invented in the late 19th century as a medical instrument for pain relief and the treatment of various ailments. Sometimes described as a massager, the vibrator is used on the body to produce sexual stimulation. Several clinical studies have found vibrators to be an effective solution for Erectile Dysfunction. Examples of FDA registered vibrators for erectile dysfunction include MV.Health's Tenuto and Reflexonic's Viberect.

Surgery

Main article: Penile implant

Often, as a last resort, if other treatments have failed, the most common procedure is prosthetic implants which involves the insertion of artificial rods into the penis. Some sources show that vascular reconstructive surgeries are viable options for some people.

Alternative medicine

The Food and Drug Administration (FDA) does not recommend alternative therapies to treat sexual dysfunction. Many products are advertised as "herbal viagra" or "natural" sexual enhancement products, but no clinical trials or scientific studies support the effectiveness of these products for the treatment of ED, and synthetic chemical compounds similar to sildenafil have been found as adulterants in many of these products. The FDA has warned consumers that any sexual enhancement product that claims to work as well as prescription products is likely to contain such a contaminant. A 2021 review indicated that ginseng had "only trivial effects on erectile function or satisfaction with intercourse compared to placebo".

History

Attempts to treat the symptoms described by ED date back well over 1,000 years. In the 8th century, males of Ancient Rome and Greece wore talismans of rooster and goat genitalia, believing these talismans would serve as an aphrodisiac and promote sexual function. In the 13th century, Albertus Magnus recommended ingesting roasted wolf penis as a remedy for impotence. During the late 16th and 17th centuries in France, male impotence was considered a crime, as well as legal grounds for a divorce. The practice, which involved inspection of the complainants by court experts, was declared obscene in 1677.

The first major publication describing a broad medicalization of sexual disorders was the first edition of the Diagnostic and Statistical Manual of Mental Disorders in 1952. In the early 20th century, medical folklore held that 90-95% of cases of ED were psychological in origin, but around the 1980s research took the opposite direction of searching for physical causes of sexual dysfunction, which also happened in the 1920s and 30s. Physical causes as explanations continue to dominate literature when compared with psychological explanations .

Treatments in the 80s for ED included penile implants and intracavernosal injections. The first successful vacuum erection device, or penis pump, was developed by Vincent Marie Mondat in the early 1800s. A more advanced device based on a bicycle pump was developed by Geddings Osbon, a Pentecostal preacher, in the 1970s. In 1982, he received FDA approval to market the product. John R. Brinkley initiated a boom in male impotence treatments in the U.S. in the 1920s and 1930s, with radio programs that recommended expensive goat gland implants and "mercurochrome" injections as the path to restored male virility, including operations by surgeon Serge Voronoff.

Modern drug therapy for ED made a significant advance in 1983, when British physiologist Giles Brindley dropped his trousers and demonstrated to a shocked Urodynamics Society audience showing his papaverine-induced erection. The current most common treatment for ED, the oral PDE5 inhibitor known as sildenafil (Viagra) was approved for use for Pfizer by the FDA in 1998, which at the time of release was the fastest selling drug in history. Sildenafil largely replaced SSRI treatments for ED at the time and proliferated new types of specialised pharmaceutical marketing which emphasised social connotations of ED and Viagra rather than its physical effects.

Anthropology

Anthropological research presents ED not as a disorder but, as a normal, and sometimes even welcome sign of healthy aging. Wentzell's study of 250 Mexican males in their 50s and 60s found that "most simply did not see decreasing erectile function as a biological pathology". The males interviewed described the decrease in erectile function "as an aid for aging in socially appropriate ways". A common theme amongst the interviewees showed that respectable older males shifted their focus toward the domestic sphere into a "second stage of life". The Mexican males of this generation often pursued sex outside of marriage; decreasing erectile function acted as an aid to overcoming infidelity thus helping to attain the ideal "second stage" of life. A 56-year-old about to retire from the public health service said he would now "dedicate myself to my wife, the house, gardening, caring for the grandchildren—the Mexican classic". Wentzell found that treating ED as a pathology was antithetical to the social view these males held of themselves, and their purpose at this stage of their lives.

In the 20th and 21st centuries, anthropologists investigated how common treatments for ED are built upon assumptions of institutionalized social norms. In offering a range of clinical treatments to 'correct' a person's ability to produce an erection, biomedical institutions encourage the public to strive for prolonged sexual function. Anthropologists argue that a biomedical focus places emphasis on the biological processes of fixing the body thereby disregarding holistic ideals of health and aging. By relying on a wholly medical approach, Western biomedicine can become blindsided by bodily dysfunctions which can be understood as appropriate functions of age, and not as a medical problem. Anthropologists understand that a biosocial approach to ED considers a person's decision to undergo clinical treatment more likely a result of "society, political economy, history, and culture" than a matter of personal choice. In rejecting biomedical treatment for ED, males can challenge common forms of medicalized social control by deviating from what is considered the normal approach to dysfunction.

Lexicology

The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina; it is now mostly replaced by more precise terms, such as erectile dysfunction (ED). The study of ED within medicine is covered by andrology, a sub-field within urology. Research indicates that ED is common, and it is suggested that approximately 40% of males experience symptoms compatible with ED, at least occasionally. The condition is also on occasion called phallic impotence. Its antonym, or opposite condition, is priapism.

References

References

1. (January 2007). "Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus". The Cochrane Database of Systematic Reviews.
2. (2023). "UpToDate". [[UpToDate]].
3. (July 2005). "Chapter 1: The management of erectile dysfunction: an AUA update". [[Elsevier]].
4. Chowdhury SH, Cozma AI, Chowdhury JH. Erectile Dysfunction. Essentials for the Canadian Medical Licensing Exam: Review and Prep for MCCQE Part I. 2nd edition. Wolters Kluwer. Hong Kong. 2017.
5. (October 2014). "Undertreatment of erectile dysfunction: claims analysis of 6.2 million patients". [[Wiley (publisher).
6. . (20 January 2021). ["Can Your Diet Cause Erectile Dysfunction?"](https://health.clevelandclinic.org/can-your-diet-cause-erectile-dysfunction/). *[[Cleveland Clinic]]*.
7. . (17 July 2019). ["Erectile Dysfunction & Heart Disease"](https://my.clevelandclinic.org/health/diseases/15029-heart-disease--erectile-dysfunction). *[[Cleveland Clinic]]*.
8. (November 2020). "Association of Diet With Erectile Dysfunction Among Men in the Health Professionals Follow-up Study". [[American Medical Association]].
9. (May 2021). "The association between plant-based diet and erectile dysfunction in Chinese men". [[BioMed Central]].
10. (November 2021). "Relationship between Dietary Patterns with Benign Prostatic Hyperplasia and Erectile Dysfunction: A Collaborative Review". [[MDPI]] on behalf of the EAU-YAU Sexual and Reproductive Health Group.
11. (June 2005). "Sexual functioning assessed in 4 double-blind placebo- and paroxetine-controlled trials of duloxetine for major depressive disorder". Physicians Postgraduate Press.
12. (1995). "The role of histamine in human penile erection". British Journal of Urology.
13. "Drugs That Can Cause Erectile Dysfunction".
14. (26 August 2015). "8 Substances That May be Killing Your Erection".
15. Cunningham GR, Rosen RC. Overview of male sexual dysfunction. In: UpToDate, Martin KA (Ed), UpToDate, Waltham, MA, 2018.
16. (2006). "Male Sexual Function". [[Springer Nature]].
17. . (2006). ["Male Sexual Dysfunction Epidemiology"](http://www.health.am/sex/more/male_sexual_dysfunction_epid/). *Armenian Health Network, Health.am*.
18. (2006). "Causes of Erectile Dysfunction". Armenian Health Network, Health.am.
19. (1998). "Erectile Dysfunction Causes". Healthcommunities.com.
20. (September 2017). "Erectile dysfunction in the elderly male". Turkish Journal of Urology.
21. (December 2020). "Aging and erectile function". The Aging Male.
22. (July 2015). "Erectile dysfunction in chronic kidney disease: From pathophysiology to management". World Journal of Nephrology.
23. (2005). "The effects of smoking on the reproductive health of men". Br J Nurs.
24. (2004). "Epidemiology of erectile dysfunction". Endocrine.
25. (2005). "The impact of vascular risk factors on erectile function". Drugs of Today.
26. (2015). "The Link Between Cigarette Smoking and Erectile Dysfunction: A Systematic Review". European Urology Focus.
27. (February 2021). "Addressing male sexual and reproductive health in the wake of COVID-19 outbreak". Journal of Endocrinological Investigation.
28. (February 2021). "Evaluating the impact of COVID-19 on male reproduction". Reproduction.
29. (2005). "Sexual function before and after mesh repair of inguinal hernia". Journal of Pharmaceutical and Biomedical Analysis.
30. (July 2010). "Bicycle riding and erectile dysfunction: a review.". The Journal of Sexual Medicine.
31. (September 2005). "Bicycle riding and erectile dysfunction: an increase in interest (and concern).". The Journal of Sexual Medicine.
32. (July 11, 2011). "Porn-Induced Sexual Dysfunction: A Growing Problem". Psychology Today.
33. (September 2021). "Pornography Addiction: An Exploration of the Association Between Use, Perceived Addiction, Erectile Dysfunction, Premature (Early) Ejaculation, and Sexual Satisfaction in Males Aged 18-44 Years". The Journal of Sexual Medicine.
34. (January 2019). "Is Pornography Use Related to Erectile Functioning? Results From Cross-Sectional and Latent Growth Curve Analyses". The Journal of Sexual Medicine.
35. (May 2015). "Is Pornography Use Associated with Sexual Difficulties and Dysfunctions among Younger Heterosexual Men?". The Journal of Sexual Medicine.
36. (1 December 2020). "Porn addiction is ruining lives, but scientists aren't convinced it's real".
37. (September 2021). "Is online pornography consumption linked to offline sexual dysfunction in young men? A multivariate analysis based on an international web-based survey". JMIR Publications Inc..
38. (2026). "GeNeDIS 2024".
39. (August 2018). "Post-finasteride syndrome and post-SSRI sexual dysfunction: two sides of the same coin?". Endocrine.
40. (2014-03-01). "Erectile Dysfunction". Biota Publishing.
41. (1995). "Use of nocturnal penile tumescence and rigidity in the evaluation of male erectile dysfunction". Urol. Clin. North Am..
42. "Tests for Erection Problems". [[WebMD]], Inc.
43. "DSM". [[American Psychiatric Association]].
44. (2022). "Diagnostic and statistical manual of mental disorders: DSM-5-TR™". American Psychiatric Association Publishing.
45. "ICD-10 Version:2019".
46. (2018). "Ultrasound evaluation of the penis". Radiologia Brasileira.
47. (January 2002). "Intraoperative Neurophysiological Monitoring of the Sacral Nervous System". Neurophysiology in Neurosurgery, A Modern Intraoperative Approach.
48. (2017). "Biothesiometry". Springer International Publishing.
49. (April 1996). "ABC of urology. Subfertility and male sexual dysfunction". BMJ.
50. (December 30, 1897). "Wonderful Medicine Free / Manhood Restored / The Great Hudyan". The Helena Weekly Independent.
51. "Phony Cures for Erectile Dysfunction". U.S. Federal Trade Commission.
52. (29 June 2018). "Encyclopedia of Reproduction - 2nd Edition". Elsevier Science.
53. "What is Erectile Dysfunction? - Urology Care Foundation".
54. (16 November 2010). "New Topical Erectile Dysfunction Drug Vitaros Approved in Canada; Approved Topical Drug Testim Proves Helpful for Erectile Dysfunction".
55. (December 2016). "Relationship between age and erectile dysfunction diagnosis or treatment using real-world observational data in the USA". International Journal of Clinical Practice.
56. (August 2010). "Can low-intensity extracorporeal shockwave therapy improve erectile function? A 6-month follow-up pilot study in patients with organic erectile dysfunction". European Urology.
57. (27 July 2020). "Shockwave Therapy for Erectile Dysfunction | ED Clinics".
58. "International Index of Erectile Function (IIEF): Guidelines on Clinical Application of IIEF patient Questionnaire". Addenbrooke's Hospital.
59. (September 2018). "Low-intensity Extracorporeal Shock Wave Therapy for Erectile Dysfunction: A Systematic Review and Meta-analysis". Urology.
60. (January 2017). "Effects of Low-Intensity Extracorporeal Shockwave Therapy on Erectile Dysfunction: A Systematic Review and Meta-Analysis". The Journal of Sexual Medicine.
61. (2019-04-01). "Men and diabetes". US Centers for Disease Control and Prevention.
62. "Erectile Dysfunction".
63. (2016-06-01). "Innovative trends and perspectives for erectile dysfunction treatment: A systematic review". Arab Journal of Urology.
64. (2019-06-01). "Application of Sex Aids in Men With Sexual Dysfunction: A Review". The Journal of Sexual Medicine.
65. (2022-11-01). "Improved erectile function after focal muscle vibrations therapy in a patient with neurogenic erectile dysfunction: a case report". The Journal of Sexual Medicine.
66. (2018-07-01). "319 Penile vibratory stimulation in penile rehabilitation after radical prostatectomy: a randomized, controlled trial". The Journal of Sexual Medicine.
67. "Dangers of Sexual Enhancement Supplements".
68. (2009). "Detection of undeclared erectile dysfunction drugs and analogues in dietary supplements by ion mobility spectrometry". Journal of Pharmaceutical and Biomedical Analysis.
69. (2008). "Determination of analogs of sildenafil and vardenafil in foods by column liquid chromatography with a photodiode array detector, mass spectrometry, and nuclear magnetic resonance spectrometry". Journal of AOAC International.
70. (2007). "Use of liquid chromatography-mass spectrometry and a chemical cleavage reaction for the structure elucidation of a new sildenafil analogue detected as an adulterant in an herbal dietary supplement". Journal of Pharmaceutical and Biomedical Analysis.
71. (2007). "Structure elucidation of a novel analogue of sildenafil detected as an adulterant in an herbal dietary supplement". Journal of Pharmaceutical and Biomedical Analysis.
72. [https://www.fda.gov/Safety/Recalls/EnforcementReports/ucm217780.htm Enforcement Report for June 30, 2010] {{Webarchive. link. (June 25, 2016 , [[United States Food and Drug Administration]])
73. [https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm048386.htm Hidden Risks of Erectile Dysfunction "Treatments" Sold Online] {{Webarchive. link. (2019-04-23 , [[United States Food and Drug Administration]], February 21, 2009)
74. (April 2021). "Ginseng for erectile dysfunction". The Cochrane Database of Systematic Reviews.
75. (2007). "Impotence: A Cultural History". University of Chicago Press.
76. (2009). "Bonk: The Curious Coupling of Science and Sex". W.W. Norton & Co.
77. (1985). "Trial by Impotence: Virility and Marriage in Pre-Revolutionary France". Vintage/Ebury.
78. (2002-04-13). "Sexual behaviour and its medicalisation: in sickness and in health". BMJ.
79. Tiefer, Leonore. (1996). "The medicalization of sexuality: Conceptual, normative, and professional issues". [[Annual Review of Sex Research]].
80. Grunt-Mejer, Katarzyna. (2022-07-03). "The history of the medicalisation of rapid ejaculation—A reflection of the rising importance of female pleasure in a phallocentric world". Psychology & Sexuality.
81. (2013). "The use of vacuum erection devices in erectile dysfunction after radical prostatectomy". Reviews in Urology.
82. (November 2005). "How (not) to communicate new scientific information: a memoir of the famous Brindley lecture". BJU International.
83. (February 2003). "A historical review of erectile dysfunction". The Canadian Journal of Urology.
84. Pacey, Susan. (2008-08-01). "The medicalisation of sex: a barrier to intercourse?". Sexual and Relationship Therapy.
85. Štulhofer, Aleksandar. (2015-04-20). "The International Encyclopedia of Human Sexuality".
86. (August 2018). "Sexual dysfunction or sexual discipline? Sexuopharmaceutical use by men as prevention and proficiency". Feminism & Psychology.
87. Tiefer, Leonore. (2001-05-01). "A new view of women's sexual problems: Why new? Why now?". The Journal of Sex Research.
88. (2020). "Cultural Differences and the Practice of Sexual Medicine". Springer International Publishing.
89. (2013). "Reimagining Global Health: An Introduction". University of California Press.
90. (2009). "Prevalence of erectile dysfunction and its treatment in a Mexican population: distinguishing between erectile function change and dysfunction". Journal of Men's Health.
91. (July 2010). "Erectile dysfunction in the community: trends over time in incidence, prevalence, GP consultation and medication use – the Krimpen study: trends in ED". J Sex Med.
92. (20 September 2011). "Bad Timing: The Problematics of Intimacy in On Chesil Beach.". PsyArt.
93. (1995). "Sexual interactions". D.C. Heath.
94. (2013). "Sexually Transmitted Disease: An Encyclopedia of Diseases, Prevention, Treatment and Issues".