On this page Jump to a section
- Key facts
- Does finasteride cause ED?
- ED rates: 1 mg vs 5 mg vs placebo
- Post-finasteride syndrome and persistent ED
- Is it finasteride, or something else?
- What each path includes
- Tadalafil with finasteride
- 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
- Finasteride 1 mg
- Year 1: erectile dysfunction 1.3% vs 0.7% with placeboPROPECIA (finasteride) label · DailyMed
- Finasteride 5 mg
- PLESS year 1: impotence 8.1% vs 3.7% with placebo; a different patient population from the hair-loss trialsPROSCAR (finasteride) label · DailyMed
- After stopping
- Postmarketing reports of ED that continued after discontinuation; frequency unknownPROPECIA (finasteride) label, section 6.2
- Tadalafil option
- Approved for ED, BPH and ED with BPH; studied started with finasteride for up to 26 weeksCialis (tadalafil) label · DailyMed
- Compounded status
- The Mendoxa compounded tablet is not FDA-approvedFDA compounding Q&A
What the ED figures mean for you
ED, low desire and ejaculation changes are different outcomes. The PROPECIA (finasteride) label reports them separately; a change in one does not mean every sexual function is affected. Use the table below to identify the outcome you want to discuss.
These are trial averages, not a diagnosis. The PROPECIA (finasteride) label and PROSCAR (finasteride) label report ED or impotence in both treatment and placebo groups. A new erection problem deserves an assessment even when the timing points to a medicine.
This page stays focused on erections. For the broader hair-treatment safety discussion, read all finasteride side effects.
Finasteride ED rates: 1 mg vs 5 mg vs placebo
Read each row against its own placebo arm: in the prostate studies, many men on placebo also reported impotence. The trials differ in age, condition and length, so the rows should not be compared as if they were one study (PROPECIA (finasteride 1 mg) label; PROSCAR (finasteride 5 mg) label).
| Label and trial | Erectile dysfunction / impotence | Decreased libido | Ejaculation | Who and how long |
|---|---|---|---|---|
| Finasteride 1 mg · PROPECIA label · Year 1 | 1.3% vs 0.7% placebo | 1.8% vs 1.3% | Ejaculation disorder 1.2% vs 0.7% | Men with hair loss; 945 on drug, 934 on placebo; 12-month trials (PROPECIA (finasteride 1 mg) label) |
| Finasteride 5 mg · PROSCAR label · PLESS year 1 | 8.1% vs 3.7% placebo | 6.4% vs 3.4% | Decreased ejaculate volume 3.7% vs 0.8% | Men with BPH; 1,524 on drug, 1,516 on placebo (PROSCAR (finasteride 5 mg) label) |
| Finasteride 5 mg · PROSCAR label · PLESS years 2–4 | 5.1% vs 5.1% placebo | 2.6% vs 2.6% | Decreased ejaculate volume 1.5% vs 0.5% | The label reports no significant difference in impotence or decreased libido in years 2–4 (PROSCAR (finasteride 5 mg) label) |
| Finasteride 5 mg · PROSCAR label · MTOPS | 18.5% vs 12.2% placebo | 10.0% vs 5.7% | Abnormal ejaculation 7.2% vs 2.3% | Men with BPH followed 4 to 6 years; 768 on drug, 737 on placebo (PROSCAR (finasteride 5 mg) label) |
Sources: PROPECIA (finasteride 1 mg) label (Table 1, revised 8/2022); PROSCAR (finasteride 5 mg) label (PLESS Table 1 and MTOPS Table 2, revised 3/2026). Figures are drug-related adverse experiences as printed on each label; placebo arms show how often the same complaint appears without the drug. Accessed Oct 24, 2026.
A higher percentage in the prostate trials does not prove that increasing the dose caused the difference. The PROPECIA (finasteride) label and PROSCAR (finasteride) label describe different populations and follow-up periods. The MTOPS figures cover several years; they are not annual rates.
Does finasteride ED go away—or persist?
The label describes recovery and persistent reports; it does not give a recovery deadline. The PROPECIA (finasteride) label says sexual adverse effects resolved in men who discontinued because of them and in most who continued. Its postmarketing section also lists sexual dysfunction that continued after discontinuation, including ED.
| Source and year | What it reports | Limit |
|---|---|---|
| FDA-hosted PROPECIA label · revised April 2012 | Postmarketing reports of sexual dysfunction that continued after discontinuation, including erectile dysfunction, libido, ejaculation and orgasm disorders (2012 PROPECIA (finasteride) label) | Voluntary reports: no frequency and no proof of cause |
| FDA safety labeling change · May 31, 2022 | FDA required new Propecia labeling on suicidal ideation and behavior, additional risk of sexual dysfunction and psychoneurocognitive adverse events (FDA letter on Propecia (finasteride) labeling) | A labeling action, not a rate |
| Narrative review · 2020 | Literature on post-finasteride syndrome is of “low scientific quality”; prevalence “has never been established” (Pereira and Coelho) | Cannot confirm or refute the syndrome |
Sources: FDA-hosted PROPECIA (finasteride) label, 2012; FDA approval letter NDA 020788/S-030, 2022; An Bras Dermatol 2020 (PMC). Accessed Oct 24, 2026.
Post-finasteride syndrome is a term for persistent sexual, psychological and physical symptoms reported after treatment. The NIH-hosted 2020 review describes limited-quality evidence and an unknown frequency; the PROPECIA (finasteride) label acknowledges persistent sexual dysfunction reports. Neither establishes that a particular person’s ED is permanent or caused solely by the drug.
The FDA letter on Propecia (finasteride) also addresses suicidal ideation and behavior. Tell your prescriber promptly about mood changes.
What to bring to your ED visit
Bring a timeline and a complete medicine list. NIDDK’s ED causes guide lists other medicines, diabetes, blood vessel disease, low testosterone and psychological factors among possible contributors. Our causes of ED guide helps you prepare for that broader conversation.
- When did you start finasteride, and when did erections change? Bring the prescription or package (PROPECIA (finasteride) label; PROSCAR (finasteride) label).
- Describe the concern in your own words: firmness, desire, ejaculation or several changes.
- List all medicines and supplements, including anything already used for erections.
- Write down what you want help with now and what you want to ask your existing prescriber.
You do not have to settle the cause before asking for help. An online visit gives the provider your symptoms and history so they can assess whether ED treatment is appropriate.
What each path includes
Treat the medicine decision and the erection problem as two conversations. Only your prescriber should decide whether finasteride continues; ED care can be assessed at the same time (PROPECIA (finasteride 1 mg) label).
| Your situation | Starting point | What to discuss |
|---|---|---|
| ED started after finasteride for hair loss | The prescriber who manages your hair treatment; PROPECIA (finasteride 1 mg) label | Timing, dose and whether to continue, change or pause is their call; do not change it on your own. You can still ask about ED care in parallel. |
| On finasteride 5 mg for an enlarged prostate and have ED | Your urologist or primary care clinician; PROSCAR (finasteride 5 mg) label and Cialis (tadalafil) label | Ask whether a daily option fits your urinary and erection symptoms. The Cialis (tadalafil) label lists 5 mg daily for BPH or ED with BPH and use initiated with finasteride for up to 26 weeks. |
| ED continues after you stopped finasteride | An ED assessment that checks other causes too (NIDDK) | Bring dates: when you started, stopped, and when symptoms began. Persistent ED is listed in the PROPECIA (finasteride) label; reports do not establish its frequency. |
| You want ED treated now, online | Mendoxa online visit; Viagra (sildenafil) label and Cialis (tadalafil) label for the standalone ingredients | Independent licensed providers assess suitability. Prescription required. The compounded tablet is not FDA-approved. |
Sources: PROPECIA (finasteride 1 mg) label; PROSCAR (finasteride 5 mg) label; Cialis (tadalafil) label; Viagra (sildenafil) label; NIDDK; FDA compounding Q&A; Mendoxa care information. Accessed Oct 24, 2026.
For the ED discussion, read ED medication options. For a change to finasteride, speak with the clinician who prescribes it (PROPECIA (finasteride) label; PROSCAR (finasteride) label).
Could Mendoxa ED care fit you?
Online ED visit · Prescription required · Independent licensed providers · Not available in California
Tadalafil with finasteride: what the labels say
The Cialis (tadalafil) label covers ED, BPH, and ED with BPH. For BPH and ED with BPH it lists 5 mg once daily at about the same time each day. When BPH treatment starts with finasteride, it lists tadalafil 5 mg daily for up to 26 weeks; the added benefit decreased from week 4 to 26.
In that 26-week study, 404 men had both ED and BPH; erectile function scores improved more with tadalafil plus finasteride than placebo plus finasteride at week 26 (IIEF change 4.7 vs 0.0) (Cialis (tadalafil) label). The ENTADFI (finasteride and tadalafil) label describes an FDA-approved combination of finasteride 5 mg and tadalafil 5 mg in one capsule to initiate BPH treatment in men with an enlarged prostate for up to 26 weeks. This is a BPH indication; it does not establish a treatment for persistent ED after hair-loss therapy.
These data apply to the prostate dose, not 1 mg hair treatment. If you also take an alpha-blocker, the Cialis (tadalafil) label advises caution and does not recommend tadalafil with alpha-blockers for BPH; see our guide to alpha-blockers and ED. For dosing context, read tadalafil and daily tadalafil.
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).
- For its injectable Parkinson’s product, 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. Tell the provider you take finasteride (PROPECIA (finasteride 1 mg) label); see ED medication and nitrates.
If ED is the problem you want treated now
Use the online visit to put your erection concerns in front of a provider. Share your symptoms, health history and medicine list, including finasteride and when you started it (PROPECIA (finasteride) label; PROSCAR (finasteride) label). Independent licensed providers assess whether treatment is appropriate. Prescription required. Mendoxa ED care explains the process.
Mendoxa offers a compounded tablet containing sildenafil, tadalafil and apomorphine. It is not FDA-approved. The Viagra (sildenafil) label, Cialis (tadalafil) label and APOKYN (apomorphine) label concern separate products; they do not establish the safety or effectiveness of this combination.
Read about the compounded combination ED tablet, then start your visit to discuss suitability. The costs below apply if prescribed.
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.
FAQ
Can finasteride cause ED?
Yes, in a minority of men. The PROPECIA (finasteride 1 mg) label reports erectile dysfunction in 1.3% of men versus 0.7% on placebo in year 1, and the PROSCAR (finasteride 5 mg) label reports impotence in 8.1% versus 3.7% in the first year of PLESS.
How long does ED last after stopping finasteride?
There is no reliable recovery deadline in the PROPECIA (finasteride) label. It reports resolution in men who discontinued because of sexual side effects and in most who continued, while also listing persistent ED after stopping in postmarketing reports. Discuss symptoms with your prescriber before changing treatment.
Is the 5 mg prostate dose worse for erections than 1 mg?
First-year rates were higher on the PROSCAR (finasteride 5 mg) label than on the PROPECIA (finasteride 1 mg) label, but the trials studied different men. In PLESS, impotence was 5.1% on both finasteride and placebo in years 2–4.
What is post-finasteride syndrome?
A term for sexual, psychological and physical symptoms reported to persist after stopping finasteride. A 2020 NIH-hosted review says the evidence cannot confirm or refute the syndrome and its frequency is unknown. The PROPECIA (finasteride) label lists persistent sexual dysfunction in postmarketing reports; those reports do not establish causation.
Can I take Cialis or Viagra while on finasteride?
A prescriber must decide. The Cialis (tadalafil) label includes a study of tadalafil started with finasteride 5 mg for BPH, and both the Cialis (tadalafil) label and the Viagra (sildenafil) label contraindicate use with nitrates or riociguat. Tell the provider you take finasteride.
Should I stop finasteride if I have ED?
Do not stop or change it without talking to the prescriber who manages it (PROPECIA (finasteride 1 mg) label; PROSCAR (finasteride 5 mg) label). You can ask about ED care at the same time; an online visit with Independent licensed providers is one option. Prescription required.
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. We checked the linked DailyMed labels and FDA documents on Oct 24, 2026. Trial percentages are copied from the labels, with each placebo group and observation period kept separate. Postmarketing reports and observational evidence cannot supply a reliable personal risk of persistent ED. We cite the FDA-hosted April 2012 label rather than an unavailable FDA Q&A. This guide focuses on erections; the separate hair guide covers broader side effects. PROPECIA (finasteride) label.
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.
- DailyMed: PROPECIA (finasteride) tablets 1 mg label, Organon, revised 8/2022. Accessed Oct 24, 2026.
- DailyMed: PROSCAR (finasteride) tablets 5 mg label, Organon, revised 3/2026. Accessed Oct 24, 2026.
- DailyMed: ENTADFI (finasteride and tadalafil) capsules label, revised 12/2021. Accessed Oct 24, 2026.
- FDA (Drugs@FDA): PROPECIA (finasteride) label revised 04/2012. Accessed Oct 24, 2026.
- FDA: Propecia (finasteride) supplement approval letter NDA 020788/S-030, 2022. Accessed Oct 24, 2026.
- Pereira AFJR, Coelho TOA. Post-finasteride syndrome. An Bras Dermatol. 2020;95(3):271-277. PMID 32317131. Accessed Oct 24, 2026.
- NIDDK: symptoms and causes of ED. 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.