Erectile dysfunction: causes, symptoms, and treatments

18 Oct 2026 · @GPNutraceuticals

Erectile dysfunction is the persistent difficulty of achieving or maintaining an erection sufficient for satisfactory sexual intercourse. Erectile dysfunction is very common, especially after age 40, and is treatable in most cases: the first step is to talk to a doctor, because it is often the first sign of problems with the heart and blood vessels, diabetes or high blood pressure. First-line treatments are lifestyle changes and drug therapy with sildenafil or tadalafil. Evidence for supplements is limited: arginine has the best data, but at high doses and especially as an aid to medications.

In this guide, learn about the causes and risk factors, when to see an andrologist or urologist, how it is diagnosed, which treatments the guidelines recommend, and what studies say about arginine, citrulline, carnitine, ginseng, maca and other supplement ingredients.

Reading time: 11 minutes

Last updated: October 2026

Scientific review: GP Nutraceuticals Team

Main sources: EAU guidelines on men's sexual health and AUA guidelines on erectile dysfunction, Cochrane review of ginseng, meta-analyses of arginine and nutraceuticals used alongside medications

Erectile dysfunction: 5 key points

The guide's central message in five points: it is a common condition, it should be investigated because it can signal other health problems, and it can be treated.

• It affects about one in two men aged 40 to 70, at least mildly, and becomes more common with age.
• In most cases, it has a physical cause, often vascular: it can precede heart disease by a few years.
• Smoking, excess weight, a sedentary lifestyle, diabetes and high blood pressure are the main risk factors, and addressing them improves erectile function.
• PDE5 inhibitor medications work for about two out of three men; if they are not enough, other effective treatments are available.
• Supplements do not replace medical visits or medications: the strongest evidence concerns high-dose arginine, with modest effects.

What you'll find in this guide

The guide starts with the definition, moves on to causes, medical visits and diagnosis, and ends with treatments, supplements and frequently asked questions.

• Causes and risk factors.
• When to see a doctor and which tests to have.
• Lifestyle, medications and other treatments according to guidelines.
• What studies say about supplements.
• Frequently asked questions.

This guide is for informational and educational purposes only and is not a substitute for advice from a doctor or other qualified healthcare professionals.

What is erectile dysfunction?

Erectile dysfunction, once called impotence, is the inability to achieve or maintain an erection for sexual intercourse in a persistent or recurring way, usually for at least three months. An isolated episode caused by fatigue, alcohol or stress is not a dysfunction and happens to everyone.

An erection is primarily a vascular process. Sexual stimulation triggers the release of nitric oxide in the corpora cavernosa of the penis, the erectile tissue: the arteries dilate, blood flow to the penis increases, and blood is trapped inside the penis. Healthy blood vessels, intact nerves, adequate hormones and a favorable mental state are therefore necessary. When any one of these elements does not function properly, the erectile response is affected.

What are the symptoms of erectile dysfunction?

The main symptom is difficulty getting or maintaining an erection firm enough for sex. Erections may also be shorter-lasting, or the erection may be lost during sex; if there is a hormonal problem, sexual desire may decrease. The duration of symptoms matters: it is considered erectile dysfunction only if the problem recurs for weeks or months. Other symptoms, such as pain or curvature of the penis, may point to specific causes that need to be investigated.

How common is erectile dysfunction?

It is the most common sexual dysfunction in adult men. In the Massachusetts Male Aging Study, about 52% of men aged 40 to 70 reported some degree of dysfunction, from mild to complete, and its frequency increases with age. However, it can also affect younger men, for whom psychological issues and lifestyle play a greater role.

What causes erectile dysfunction?

In most men over 40, the cause is organic, meaning physical, but erectile dysfunction can also have emotional causes, and several factors often combine. Possible causes include:

• vascular: atherosclerosis narrows the arteries in the penis, which are small and become diseased before those of the heart. This is called erectile dysfunction of vascular origin, often linked to endothelial dysfunction: it can appear several years before a heart attack or angina and is a warning sign for heart health;
• metabolic: diabetes, high cholesterol, excess weight and metabolic syndrome damage blood vessels and nerves;
• hormonal: low testosterone mainly reduces sexual desire, while thyroid or prolactin problems are less common;
• neurological: spinal cord injuries, multiple sclerosis, diabetic neuropathy, prostate or pelvic surgery;
• anatomical: for example, Peyronie's disease, which curves the penis and can cause erectile dysfunction;
• medications: some can cause erectile dysfunction, such as certain antihypertensives, antidepressants, antiandrogens and prostate medications;
• psychological: performance anxiety, stress, depression and relationship problems, which may be the main cause in younger people or may occur alongside an organic cause; other possible causes also include relationship difficulties.

Risk factors for erectile dysfunction

The risk is higher in people who:

• is over 40-50 years old;
• smokes;
• is overweight or gets little physical activity;
• has diabetes, high blood pressure or high cholesterol;
• drinks a lot of alcohol or uses drugs;
• has sleep apnea or does not get enough sleep;
• has urinary symptoms caused by an enlarged prostate, which are often associated with erection problems.

When should you see a doctor and how is it diagnosed?

When should you see a doctor about erectile dysfunction?

It is a good idea to talk to your family doctor, andrologist or urologist when the problem recurs for several weeks or causes distress, even if it is mild. The visit helps treat erectile dysfunction and also check your heart, blood pressure, blood sugar and cholesterol: in many men, erectile dysfunction is an opportunity to discover previously undiagnosed diabetes or a heart problem. See a doctor without delay if the problem appeared suddenly after an injury or surgery, if you have chest pain during exertion, or if an erection lasts more than four hours (priapism, a medical emergency).

How is erectile dysfunction diagnosed?

According to the guidelines of the European Association of Urology (EAU) and the American Urological Association (AUA), the basic assessment includes:

• interview: how long the problem has lasted, whether nighttime or morning erections are preserved, libido, ejaculation, medications, habits and relationship status;
• IIEF-5 questionnaire: five questions with a score from 5 to 25, which measures severity (a score below 22 indicates dysfunction) and is used to track treatment results;
• examination: genitals, sexual characteristics, blood pressure and, if indicated, the prostate;
• blood tests: laboratory tests such as blood glucose or glycated hemoglobin, cholesterol and triglycerides, and morning total testosterone;
• cardiovascular risk assessment, before starting treatment and before resuming sexual activity if the heart is not in good condition.

More in-depth tests, such as a penile color Doppler ultrasound, are reserved for complex cases, people who do not respond to treatment, or when other causes of the problem are suspected, such as neurological causes.

Erectile dysfunction: remedies and treatments

To treat erectile dysfunction, EAU and AUA guidelines recommend a person-centered approach: harmful habits are addressed, treatment is chosen with the doctor according to the cause, effectiveness, side effects, and preferences, and the partner is involved when possible.

Lifestyle and prevention of erectile problems

Changing habits is the best way to prevent erectile dysfunction, helps improve erectile function, and protects the heart:

• stop smoking;
• get regular physical activity, for example 150 minutes a week of brisk walking or cycling;
• lose weight if overweight;
• follow a Mediterranean-style diet;
• limit alcohol and get enough sleep;
• keep diabetes, blood pressure, and cholesterol under control;
• review medications that may worsen erections with a doctor.

Medications for erectile problems

The first choice is phosphodiesterase type 5 (PDE5) inhibitors: sildenafil, tadalafil, vardenafil, and avanafil. They work only in the presence of sexual stimulation and are effective for about two out of three men. They differ mainly in how long they work: tadalafil lasts up to 36 hours and can also be taken daily at a low dose. The most common side effects are headache, facial flushing, and a stuffy nose. They must not be used with nitrates for angina because of the risk of a severe drop in blood pressure. They are available only by prescription: those sold online without a prescription are often counterfeit.

If testosterone levels are low, the doctor may consider testosterone replacement therapy, which mainly improves sexual desire. For psychological causes, sex or couples therapy can be helpful on its own or alongside medication.

Other treatments and surgery

When oral medications are not enough or cannot be used, other options are available:

• alprostadil, injected into the corpora cavernosa or applied as a cream inside the urethra;
• vacuum device, a cylinder that draws blood into the penis;
• low-intensity shockwave therapy, proposed for mild cases of vascular origin, with results that still need to be confirmed over the long term;
• penile prosthesis, a surgical procedure reserved for cases that do not respond to other treatments, with high patient satisfaction.

Supplements for erectile dysfunction: what do studies say?

Among the most studied natural substances are amino acids that support nitric oxide production, such as arginine and citrulline, carnitine, and certain plants such as ginseng, maca, and tribulus. Systematic reviews conclude that the evidence is generally low quality: studies are small and short, and the products and doses vary widely.

Scientific evidence and regulatory claims are two different things. A label claim describes a physiological function recognized by an authority and does not prove that a product treats the disorder. Likewise, a favorable study does not, by itself, authorize a claim.

Studies on individual supplement ingredients

In studies, these products were generally well tolerated. However, arginine dilates blood vessels, like erectile dysfunction medications: anyone taking nitrates or antihypertensives should talk to their doctor first.

What a supplement can claim

No ingredient has an EU-authorized health claim relating to erections or sexual function. For niacin, Regulation (EU) 432/2012 allows general claims, for example about normal psychological function and the reduction of tiredness. In Italy, for certain plants such as damiana, tribulus, or ginseng, the Ministry of Health allows label statements such as “tonic action,” which describe a physiological effect, not the treatment of a disorder.

Frequently asked questions about erectile dysfunction

Brief answers to the most common questions: whether it can be cured, how to identify the cause, its link to the heart, medication safety, testosterone, and supplements.

Can erectile dysfunction be cured?

Often, yes, or at least it can be managed very well. When erectile dysfunction is due to smoking, excess weight, medication, or anxiety, it can improve by addressing the cause. In cases related to diabetes or blood vessel damage, medication allows most people to have satisfying sex.

How can you tell whether erectile dysfunction is caused by a physical or psychological issue?

One clue is nighttime and morning erections: if they are still occurring, the blood vessels and nerves are working, and the cause is more likely psychological. A sudden onset related to a stressful period or a new relationship also suggests an emotional cause, while gradual worsening points to a physical cause. The two factors often coexist, and a doctor should assess the situation.

What is the link between erectile dysfunction and cardiovascular risk?

The arteries in the penis are smaller than those in the heart and are affected by atherosclerosis sooner. For this reason, erectile dysfunction can precede a heart problem by several years, and those affected should check their blood pressure, cholesterol, blood sugar, and habits.

Are erectile dysfunction medications dangerous for the heart?

They are considered safe for people with stable heart disease who have been assessed by a doctor. However, they must not be taken with nitrates and should be used with caution with some blood pressure medications, due to the risk of blood pressure dropping too much. After a heart problem, a cardiologist should be consulted before resuming sexual activity.

Should testosterone be checked?

Guidelines recommend measuring total testosterone in the morning in people with erectile dysfunction, especially if their sex drive has decreased. If it is low, correcting it can improve sex drive and response to medication.

Do supplements work for erectile dysfunction?

The evidence is limited. Arginine has the best evidence, especially at 5-6 grams a day and as an aid to medication; for ginseng, maca, and tribulus, the observed benefits are small and there are few studies. A supplement does not replace a medical examination, which is also needed to detect problems such as diabetes or heart problems.

Erectile dysfunction at a glance

Erectile dysfunction is common, especially after age 40, and in most cases has a physical cause, often related to blood vessels, metabolism, or lifestyle. It should always be mentioned to a doctor, because it can be the first sign of a heart problem.

Care starts with lifestyle: quitting smoking, being active, losing weight, and monitoring blood pressure, blood sugar, and cholesterol. PDE5 inhibitor medications work for most men and, if they are not enough, other effective treatments are available. Evidence for supplements is weak: arginine has the best data, with modest effects.

The GP Nutraceuticals nutraceutical approach

A supplement is not a treatment and does not replace a doctor's assessment or, when needed, medication. It can complement the healthy habits described in this guide.

ProRetil Max is a dietary supplement in sachets that combines, per two sachets, L-arginine (2000 mg), L-citrulline (1000 mg), carnitine (1000 mg), L-ornithine (800 mg), dry extracts of ashwagandha (400 mg), damiana (200 mg), tribulus, Panax ginseng, muira puama, and maca (100 mg each), guarana (20 mg), taurine (200 mg), and niacin (16 mg). Take 1-2 sachets per day.

Among the approved label claims:

• ashwagandha: adaptogenic tonic;
• damiana, tribulus, and guarana: tonics, useful in cases of physical and mental fatigue;
• muira puama and ginseng: tonics and antioxidants;
• maca: tonic and metabolic support;
• niacin contributes to normal psychological function and the reduction of tiredness and fatigue.

Arginine, carnitine, and niacin were studied together in an Italian study of 54 men, with an improvement in the IIEF score after three months; the authors themselves describe it as preliminary because it did not have a placebo group. The studies described in this guide used preparations and quantities often different from those in a dietary supplement (for example, 6 g per day of arginine or 2.4 g of maca), so their results cannot be attributed to the product. The product should not be used during pregnancy, by children, or for prolonged periods without consulting a doctor. If you take nitrates, antihypertensives, or erectile dysfunction medications, or have heart problems, talk to your doctor first.

Scientific sources and references

This guide is based on three types of sources: guidelines from scientific urology societies, epidemiological studies and systematic reviews, and randomized clinical trials published in peer-reviewed journals.

Guidelines and institutional sources on erectile dysfunction

• European Association of Urology. EAU Guidelines on Sexual and Reproductive Health. uroweb.org
• Burnett AL, Nehra A, Breau RH, et al. Erectile Dysfunction: AUA Guideline. J Urol. 2018. doi.org
• Regulation (EU) No 432/2012 of the Commission, establishing a list of permitted health claims made on foods. eur-lex.europa.eu

Studies on the prevalence of erectile dysfunction

• Feldman HA, Goldstein I, Hatzichristou DG, et al. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol. 1994. doi.org

Studies on supplements for erectile problems

• Rhim HC, Kim MS, Park YJ, et al. The Potential Role of Arginine Supplements on Erectile Dysfunction: A Systemic Review and Meta-Analysis. J Sex Med. 2019. doi.org
• Menafra D, de Angelis C, Garifalos F, et al. Long-term high-dose L-arginine supplementation in patients with vasculogenic erectile dysfunction: a multicentre, double-blind, randomized, placebo-controlled clinical trial. J Endocrinol Invest. 2022. doi.org
• Barbonetti A, Tienforti D, Antolini F, et al. Nutraceutical interventions for erectile dysfunction: a systematic review and network meta-analysis. J Sex Med. 2024. doi.org
• Gentile V, Vicini P, Prigiotti G, et al. Preliminary observations on the use of propionyl-L-carnitine in combination with sildenafil in patients with erectile dysfunction and diabetes. Curr Med Res Opin. 2004. doi.org
• Gianfrilli D, Lauretta R, Di Dato C, et al. Propionyl-L-carnitine, L-arginine and niacin in sexual medicine: a nutraceutical approach to erectile dysfunction. Andrologia. 2012. doi.org
• Lee HW, Lee MS, Kim TH, et al. Ginseng for erectile dysfunction. Cochrane Database Syst Rev. 2021. doi.org
• Kamenov Z, Fileva S, Kalinov K, Jannini EA. Evaluation of the efficacy and safety of Tribulus terrestris in male sexual dysfunction: a prospective, randomized, double-blind, placebo-controlled clinical trial. Maturitas. 2017. doi.org
• Zenico T, Cicero AFG, Valmorri L, et al. Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial. Andrologia. 2009. doi.org

Update history

We update this guide when new guidelines or relevant studies are published.

Version 1.0 – October 2026

First published. Main sources: EAU guidelines on sexual and reproductive health and AUA guidelines on erectile dysfunction, Massachusetts Male Aging Study, Cochrane review on ginseng, meta-analyses on arginine and nutraceuticals used alongside medications.