On this page Jump to a section
- Key facts
- What causes ED?
- Causes of ED, cause by cause
- ED as an early warning of heart disease
- Causes of ED in young men
- How the cause is found
- What each path includes
- Safety checks before ED medication
- If ED is the problem you want treated now
- Mendoxa plans and prices
- FAQ
- How we wrote this
- Sources and references
Key facts at a glance
- How common
- 52% reported some degree of ED in a historical study of men ages 40–70Massachusetts Male Aging Study · PubMed
- Diabetes
- More than half of men with diabetes will get EDNIDDK
- Compounded status
- The Mendoxa compounded tablet is not FDA-approvedFDA compounding Q&A
Why erections weaken: blood flow, nerves, hormones and stress
ED can involve the body, mental health or both. NIDDK lists conditions affecting blood vessels, nerves and hormones, alongside emotional and lifestyle factors. Finding the cause starts with your health and sexual history, rather than assuming every weak erection has the same explanation.
This page focuses on the reasons for impotence and what to ask about each. For the meaning of ED, see impotence explained; for treatment options, use our erectile dysfunction treatment guide.
Causes of ED, cause by cause: evidence, what to test, where to read more
Find the factors that fit your history, then bring those rows to your visit. The evidence column distinguishes causes listed by health authorities from observational associations; the checks column offers questions, not a self-diagnosis or a required testing panel.
| Cause | How common / what the source shows | What to test or ask | Mendoxa guide |
|---|---|---|---|
| Blood-vessel disease (narrowed or stiff arteries, high cholesterol) | Cleveland Clinic: “Vascular ED is the most common type of ED.” | Blood pressure, cholesterol (lipid panel) and a heart-risk review | ED pills and your heart; Statins and ED |
| Diabetes | NIDDK: “More than half of men with diabetes will get ED,” which makes diabetes worth discussing during an ED evaluation | Ask whether your blood sugar should be checked; bring any diabetes results | ED and diabetes |
| High blood pressure and its medicines | High blood pressure is listed by NIDDK among conditions linked to ED; the Zestril (lisinopril) label lists impotence among reactions | Blood pressure reading and a review of every pressure medicine; do not stop one on your own | ED and blood pressure; Lisinopril and ED |
| Other medicines | NIDDK: ED “can be a side effect of many common prescription and over-the-counter medicines.” In year 1 of trials, ED was reported by 1.3% on finasteride vs 0.7% on placebo (Propecia (finasteride) label). The Flomax (tamsulosin) label lists abnormal ejaculation; describe whether your problem is ejaculation or erection | A full list of prescriptions, OTC drugs and supplements, with start dates | Antidepressants and ED; Finasteride and ED; Tamsulosin and ED; Stimulant ADHD medicine and ED; GLP-1 weight-loss injections and ED |
| Low testosterone and other hormone problems | NIDDK lists hormone problems among causes; University of Utah Health names low testosterone and high prolactin | Testosterone blood test, which Cleveland Clinic lists among ED blood tests; mention low sex drive | Low testosterone and ED |
| Anxiety, depression and stress | NIDDK: mental health or emotional issues “can either cause ED or make it worse”; depression was linked to ED in the Massachusetts Male Aging Study | Whether erections still happen at night or in the morning; NIDDK describes a nocturnal erection test | Performance anxiety and ED |
| Smoking and vaping | Daily vaping: adjusted odds ratio 2.24 vs never use in a US survey of men age 20 and older; association, not proof of cause (El-Shahawy et al.). NIDDK lists smoking cigarettes | Your nicotine history; ask about quitting | Vaping and ED |
| Heavy alcohol use | NIDDK lists “drinking too much alcohol”; MedlinePlus lists alcohol among recreational drugs that may cause erection problems | How much and how often you drink; whether problems happen only after drinking | ED and alcohol; Dehydration and ED |
| Cannabis (weed) | Cleveland Clinic and MedlinePlus list marijuana among substances that may cause ED | Frequency of use and any other drugs | Weed and ED |
| Sleep apnea | A review of 28 observational studies concluded “OSA is associated with a higher risk of ED” (Kellesarian et al. 2018); this association does not prove that treating apnea will resolve ED | Any diagnosed apnea or sleep concerns; ask whether a sleep evaluation fits | Can ED be reversed? |
| Pelvic surgery, radiation and prostate problems | NIDDK lists “damage from pelvic surgery” and enlarged prostate; University of Utah Health adds pelvic radiation | Dates of surgery or radiation; urinary symptoms | Tamsulosin and ED; The ED shot |
Sources: NIDDK causes; NIDDK diabetes; NIDDK diagnosis; MedlinePlus; Cleveland Clinic; University of Utah Health; MMAS; Kellesarian 2018; PATH study; Propecia (finasteride) label; Flomax (tamsulosin) label; Zestril (lisinopril) label. Accessed Oct 24, 2026.
Bring medication start dates to the visit. For example, the Propecia (finasteride) label records sexual adverse reactions; a timing match is a reason for a prescriber review, not proof that a drug caused your ED. NIDDK advises against stopping prescribed medicine on your own.
Wondering about dehydration? The sources in this table do not establish dehydration as a cause of ongoing ED. Our dehydration and ED guide addresses that separate question; do not assume it explains recurring symptoms.
ED as an early warning sign of heart disease
ED can be a reason to check cardiovascular risk. In a 2005 study of 9,457 men age 55 and older in the placebo arm of the Prostate Cancer Prevention Trial, existing or newly developed ED was associated with a hazard ratio of 1.45 for later cardiovascular events. This is a study association, not a diagnosis or a personal risk estimate.
Ask your clinician about cardiovascular risk factors alongside erection symptoms. The Viagra (sildenafil) label says sildenafil should not be used when sexual activity is inadvisable because of cardiovascular status. Our Viagra and heart health guide covers that treatment question.
Causes of ED in young men
Being young does not rule out a physical cause. A 2017 review describes both psychological and physical causes in young men. In one Italian clinic study published in 2013, 114 of 439 patients seeking first help for new ED were 40 or younger (26%). That measures the clinic’s patients, not how common ED is among all young men.
The review describes sudden onset with preserved spontaneous erections as a pattern seen with psychological causes, while physical causes tend to develop gradually. These are clues for a history, not a way to diagnose yourself. Start with performance anxiety and ED, vaping and ED or weed and ED if those fit your situation, and discuss persistent symptoms with a clinician.
How a clinician finds the cause of ED
History first, tests as needed. NIDDK describes a medical, sexual and mental-health history, a physical exam, blood tests, penile blood-flow ultrasound, a nocturnal erection test and an injection test. The Viagra (sildenafil) label also says the evaluation of ED should include a determination of potential underlying causes.
- When did it start, and was the start sudden or gradual?
- Is the problem getting hard, staying hard, or low desire?
- Do you still have morning or nighttime erections?
- Every medicine and supplement, plus nicotine, alcohol and drug use.
- Any known heart disease, diabetes, high blood pressure, sleep problems or pelvic surgery.
Bring this list to any visit, including an online one. See our erectile dysfunction treatment hub for treatment options once the cause is clearer.
What each path includes
Choose the next step by the question you need answered. Use an online ED visit to discuss prescription suitability, and bring concerns that need an examination or testing to the relevant clinician. The table is a visit-planning guide, not a diagnosis.
| Your situation | Starting point | What it includes |
|---|---|---|
| Possible heart, diabetes or blood-pressure cause | Primary care clinician (PCPT findings) | Blood pressure, cholesterol and blood sugar review; heart-risk follow-up |
| Suspected medicine side effect | The prescriber of that medicine (NIDDK) | Review the timeline with your prescriber; the finasteride label is one example of a label recording sexual adverse reactions |
| Stress, anxiety or depression | Counselor or mental-health clinician (NIDDK) | Talking therapy, sometimes with your partner |
| Known sleep apnea or sleep concerns | Sleep evaluation (OSA review) | Sleep study and sleep-apnea treatment options |
| You want to discuss an ED prescription | Online visit or in-person clinician; Viagra (sildenafil) label, Cialis (tadalafil) label | Health and medicine review; Prescription required |
| You want to know whether Mendoxa fits | Mendoxa online assessment | Independent licensed providers assess suitability; the compounded tablet is not FDA-approved |
Sources: PCPT; NIDDK treatment; OSA review; Viagra (sildenafil) label; Cialis (tadalafil) label; FDA compounding Q&A; Mendoxa care information. Accessed Oct 24, 2026.
These paths can run in parallel: treating ED does not replace checking the cause. Compare ED medication options before your visit.
Could Mendoxa ED care fit you?
Online ED visit · Prescription required · Independent licensed providers · Not available in California
Safety checks before ED medication
- Sildenafil and tadalafil are contraindicated with organic nitrates or riociguat (Viagra (sildenafil) label; Cialis (tadalafil) label).
- An erection lasting more than 4 hours needs immediate medical care (Viagra (sildenafil) label; Cialis (tadalafil) label).
- Stop and seek care for sudden vision loss or sudden decrease or loss of hearing (Viagra (sildenafil) label; Cialis (tadalafil) label).
- Common adverse effects include headache and flushing with sildenafil, and headache, indigestion and back pain with tadalafil (Viagra (sildenafil) label; Cialis (tadalafil) label).
- The APOKYN (apomorphine) label contraindicates use with 5HT3 antagonists such as ondansetron and warns about nausea and fainting.
Do not add another ED medicine to an existing treatment on your own: the Viagra (sildenafil) label and Cialis (tadalafil) label say combinations with other PDE5 inhibitors or ED therapies have not been studied and advise against such use. See ED medication and nitrates.
If ED is the problem you want treated now
Start with an assessment of your symptoms. Share your health history, current medicines and the possible causes from the table above. Independent licensed providers decide whether treatment is appropriate. Prescription required. Mendoxa ED care explains the process.
Use the assessment to explain when the problem started, what changed around that time and what you want help with. Treatment depends on the provider’s assessment; an online visit does not replace any examination or testing they recommend. Read how an online ED prescription works before starting. Mendoxa product details and costs appear below.
Mendoxa ED plans and prices
The Mendoxa ED tablet is a compounded rapid-dissolve tablet with sildenafil (the active ingredient in Viagra), tadalafil (the active ingredient in Cialis) and apomorphine (APOKYN label). It dissolves under the tongue. A licensed clinician decides if it fits you and selects the strength. Compounded medicines are not FDA-approved.
| Tablets per month | 1-month total | Per tablet (1 month) | 3-month total | Per tablet (3 months) |
|---|---|---|---|---|
| 6 tablets / month | $129 | $21.50 | $329 | $18.28 |
| 10 tablets / month | $149 | $14.90 | $379 | $12.63 |
| 20 tablets / month | $179 | $8.95 | $449 | $7.48 |
The 3-month total covers three months at the monthly tablet quantity shown.
If prescribed · Cancel anytime · Available in 49 states (not California). Prices from the Mendoxa intake at try.mendoxa.co/f/ed on Oct 24, 2026. The intake always shows the current price.
Next step after finding a likely cause: which doctor treats ED. More causes we cover: gout, uric acid and allopurinol and why you can't stay hard.
Before looking for causes, match the signs: ED symptoms checklist. Drinking as a cause: ED and alcohol.
Medicines that can play a role: antidepressants and ED. Morning erections as a clue: no morning wood.
Mood as a cause: depression and ED. What to eat for healthier blood flow: foods that help ED.
For partners wondering what is going on: why your partner can't stay hard.
Everyday habits, checked against the studies: nicotine and ED and caffeine and ED.
Related reading: gabapentin and ED, anabolic steroids and ED, blood thinners and ED.
FAQ
What is the most common cause of ED?
Blood-flow problems are the most common cause, according to Cleveland Clinic. Several factors can overlap, so the useful next question is which fit your health history.
Why do I have erectile dysfunction suddenly?
A review of ED in young men describes sudden onset as a pattern seen with psychological causes, especially when spontaneous erections remain good. Timing alone cannot establish the cause; tell your clinician when it began and what else changed.
What can cause erectile dysfunction at 30?
Both psychological and physical causes occur in young men, including anxiety, depression, vascular, hormonal and nerve-related problems (2017 review). Our performance anxiety guide covers one possible contributor.
Is ED a sign of heart disease?
It can be an early warning of cardiovascular problems, but ED alone does not diagnose heart disease. A prospective study linked ED with later cardiovascular events and recommended investigating cardiovascular risk factors.
Which medicines can cause erection problems?
The Propecia (finasteride) label reports ED in its trials, and the Zestril (lisinopril) label lists impotence among adverse reactions. Ask your prescriber to review your medicines; NIDDK says not to stop them on your own.
Does masturbation cause ED?
University of Utah Health reports no consistent link between masturbation and ED. If you have recurring erection problems, discuss the pattern with a clinician rather than assuming masturbation explains it.
Ready to see if the Mendoxa ED tablet fits you?
From $129/month if prescribed · Cancel anytime · Available in 49 states (not California)
How we wrote this
Written by the Mendoxa editorial team · Sources: DailyMed/FDA. Medical facts on this page come from the FDA-approved labels on DailyMed and Drugs@FDA; each drug name links to its label. Cause and diagnostic information also comes from NIH sources, the linked clinic pages and PubMed studies, checked Oct 24, 2026. Study dates and populations matter: an association does not establish a cause, and a clinic sample is not a population prevalence estimate. Table checks are topics to discuss with a clinician, not tests everyone needs. Separate drug labels do not establish the safety or effectiveness of a compounded combination.
Updated Oct 24, 2026. This page is general information, not medical advice. A licensed clinician decides what fits you.
References
- DailyMed: VIAGRA (sildenafil citrate) tablet, film coated, label revised 12/2017. Accessed Oct 24, 2026.
- DailyMed: CIALIS (tadalafil) tablet, film coated, label revised 3/2026. Accessed Oct 24, 2026.
- DailyMed: APOKYN (apomorphine hydrochloride) injection, label revised 6/2022. Accessed Oct 24, 2026.
- FDA (Drugs@FDA): VIAGRA (sildenafil) prescribing information, NDA 020895. Accessed Oct 24, 2026.
- FDA (Drugs@FDA): CIALIS (tadalafil) prescribing information, NDA 021368. Accessed Oct 24, 2026.
- FDA: Compounding and the FDA, questions and answers. Accessed Oct 24, 2026.
- NIDDK: symptoms and causes of ED. Accessed Oct 24, 2026.
- NIDDK: definition and facts for ED. Accessed Oct 24, 2026.
- NIDDK: diagnosis of ED. Accessed Oct 24, 2026.
- NIDDK: treatment for ED. Accessed Oct 24, 2026.
- NIDDK: diabetes, sexual and bladder problems. Accessed Oct 24, 2026.
- MedlinePlus: drugs that may cause erection problems. Accessed Oct 24, 2026.
- Feldman HA, et al. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol. 1994;151(1):54-61. PMID 8254833. Accessed Oct 24, 2026.
- Thompson IM, et al. Erectile dysfunction and subsequent cardiovascular disease. JAMA. 2005;294(23):2996-3002. PMID 16414947. Accessed Oct 24, 2026.
- Capogrosso P, et al. One patient out of four with newly diagnosed erectile dysfunction is a young man. J Sex Med. 2013;10(7). PMID 23651423. Accessed Oct 24, 2026.
- Nguyen HMT, et al. Erectile Dysfunction in Young Men: A Review of the Prevalence and Risk Factors. Sex Med Rev. 2017. PMID 28642047. Accessed Oct 24, 2026.
- Kellesarian SV, et al. Association between obstructive sleep apnea and erectile dysfunction: a systematic review and meta-analysis. Int J Impot Res. 2018. PMID 29795528. Accessed Oct 24, 2026.
- El-Shahawy O, et al. Association of E-Cigarettes With Erectile Dysfunction: The PATH Study. Am J Prev Med. 2022;62(1):26-38. PMID 34922653. Accessed Oct 24, 2026.
- Cleveland Clinic: erectile dysfunction. Accessed Oct 24, 2026.
- University of Utah Health: erectile dysfunction. Accessed Oct 24, 2026.
- DailyMed: Propecia (finasteride) label. Accessed Oct 24, 2026.
- DailyMed: Flomax (tamsulosin) label. Accessed Oct 24, 2026.
- DailyMed: Zestril (lisinopril) label. Accessed Oct 24, 2026.
- Mendoxa ED care (product, format, max 1 dose per 24 hours). Accessed Oct 24, 2026.
- Mendoxa ED intake: plan prices (term_options). Accessed Oct 24, 2026.
About Mendoxa
Mendoxa (mendoxa.co) is a US telehealth brand. Independent licensed providers (licensed clinicians in the LocumTele network) review each online visit, and prescriptions are filled by Rush Pharmacy, a licensed US pharmacy. Available in 49 states (not California).
- Prescription required. A licensed clinician reviews every visit and can say no. A prescription is not automatic.
- A compounded medicine is not an FDA-approved finished product (FDA compounding Q&A).
- Plans: 1 month or 3 months, from $129. If prescribed · Cancel anytime · Available in 49 states (not California).
Compounded medication prescribed only if a licensed U.S. clinician decides it is appropriate. Not FDA-approved as a finished product. Not available in California. This site is not for emergencies. Call 911 if you need urgent care.