On this page Jump to a section
- Key facts
- Does testosterone help ED?
- October 2026 update
- What the trials show
- TRT vs ED pills
- Can TRT cause ED?
- Testosterone plus ED pills
- 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
- Approved use
- Testosterone is approved for low testosterone with an associated medical condition, not for EDKyzatrex (testosterone undecanoate) label
- Who qualifies
- Two early-morning total testosterone results below 300 ng/dL plus symptoms or signs (the testosterone cypionate label also requires low morning results on separate days)NIH-hosted paper summarizing AUA criteria
- Erection trials
- TRAVERSE (2024): testosterone improved desire and sexual activity, but not erectile function versus placebo; labeled use remains replacement for deficiency (Kyzatrex (testosterone undecanoate) label)Pencina et al. · PubMed
- Separate treatment decisions
- Clinicians may prescribe testosterone with a PDE5 inhibitor when ED and low testosterone coexist (Viagra (sildenafil) label; Kyzatrex (testosterone undecanoate) label)NIDDK: ED treatment
- Compounded status
- The Mendoxa compounded tablet is not FDA-approved; Mendoxa does not offer testosteroneFDA compounding Q&A
Who should consider testosterone replacement therapy for ED?
Confirm deficiency before discussing TRT. The AUA criteria summarized in a NIH-hosted summary of AUA criteria are two early-morning total testosterone results below 300 ng/dL plus symptoms or signs; the testosterone cypionate label requires low morning measurements on at least two separate days before treatment.
A low result is a reason for a clinical assessment, not a promise of better erections: testosterone replaces deficiency associated with specific medical conditions, and safety and efficacy for age-related hypogonadism have not been established (Kyzatrex (testosterone undecanoate) label; testosterone cypionate label).
For the separate question of causes, read can low testosterone cause ED? Here, the focus is whether treatment improves erections—and what to do if it does not.
October 2026: new testosterone options from a telehealth company
October 2026 update. On October 21, 2026, Hims announced injectable TRT in compounded and commercial forms, including generic testosterone cypionate, plus oral Kyzatrex (Hims launch announcement). Product indications remain those in the testosterone cypionate label and Kyzatrex (testosterone undecanoate) label.
More ways to get testosterone do not change who it is for. The Kyzatrex (testosterone undecanoate) label limits use to conditions associated with a deficiency or absence of endogenous testosterone, and the testosterone cypionate label has the same deficiency-based indication. Neither label lists erectile dysfunction as an indication, and compounded versions are not FDA-approved.
What the trials show for erections
The evidence does not support promising better erections from TRT. The PubMed abstracts below report different erectile-function findings in low-testosterone populations; TRT’s labeled role remains replacement for deficiency (Kyzatrex (testosterone undecanoate) label).
| Trial (PubMed) | Who was studied | Erection result in the abstract |
|---|---|---|
| Testosterone Trials, NEJM 2016 | 790 men aged 65+ with testosterone below 275 ng/dL and symptoms; gel or placebo for 1 year | Higher testosterone was associated with “significantly increased sexual desire and erectile function”; authors called the sexual-function benefit “moderate” |
| Sexual Function Trial analysis, JCEM 2016 | 470 men aged 65+ with low libido and average testosterone below 275 ng/dL | This analysis of the same trial linked hormone increases to activity and desire, but not erectile-function changes; it does not negate the trial’s overall treatment result |
| TRAVERSE Sexual Function Study, JCEM 2024 | 1,161 men aged 45–80 with two results below 300 ng/dL, low libido and heart disease or higher heart risk; testosterone gel vs placebo | Improved sexual activity, symptoms and desire, “but not erectile function, compared with placebo” |
Sources: Snyder et al., NEJM 2016 (PubMed); Cunningham et al., JCEM 2016 (PubMed); Pencina et al., JCEM 2024 (PubMed). Accessed Oct 22, 2026. Labeled indication: Kyzatrex (testosterone undecanoate) label.
How to use these findings: distinguish desire from erection quality when discussing progress with your prescriber; the TRAVERSE abstract reports improvement in desire without improvement in erectile function (TRAVERSE PubMed abstract; Kyzatrex (testosterone undecanoate) label for the labeled indication). These abstracts do not establish a benefit in men with normal testosterone or a reliable time until erections improve. Explore other treatment questions in can ED be reversed?
TRT vs ED pills: what each treats
The quickest way to see why testosterone is not a shortcut to firmer erections is to put the labeled uses side by side.
| Medicine | FDA-labeled use | ED as an indication? | What has to be true first |
|---|---|---|---|
| Testosterone (TRT) | Testosterone deficiency from primary or hypogonadotropic hypogonadism (Kyzatrex (testosterone undecanoate) label) | Not listed in the Kyzatrex (testosterone undecanoate) label | Blood tests confirming low testosterone (AUA criteria summary) |
| Sildenafil | Erectile dysfunction (Viagra (sildenafil) label) | Yes, the labeled indication | Requires sexual stimulation (Viagra (sildenafil) label) |
| Tadalafil | Erectile dysfunction and BPH symptoms (Cialis (tadalafil) label) | Yes, the labeled indication | Requires sexual stimulation (Cialis (tadalafil) label) |
Sources: Kyzatrex (testosterone undecanoate) label; testosterone cypionate label; Viagra (sildenafil) label; Cialis (tadalafil) label; NIH-hosted AUA criteria summary. Accessed Oct 22, 2026.
Compare prescription choices in our ED medications guide and the broader erectile dysfunction guide.
Can TRT cause ED?
Persistent ED on TRT does not, by itself, show that TRT caused it. The testosterone cypionate label lists changes in libido and overly frequent or prolonged erections; the Kyzatrex (testosterone undecanoate) label warns about sperm suppression and fertility. These are distinct from evidence that prescribed TRT causes ED.
| Area | What the label says | What to raise with your prescriber |
|---|---|---|
| Sex drive | “Increased or decreased libido” is listed among adverse reactions (testosterone cypionate label) | Changes in desire after starting |
| Erections | Priapism and overly frequent or persistent erections are label concerns (testosterone cypionate label) | Any erection lasting hours |
| Sperm and fertility | May cause azoospermia; reduced fertility observed, and the impact “may be irreversible” (Kyzatrex (testosterone undecanoate) label) | Plans for children before starting |
| Testicles | Testicular atrophy, subfertility and infertility reported in men who abuse anabolic steroids (Kyzatrex (testosterone undecanoate) label) | Doses above the prescription |
| Blood pressure | Can increase blood pressure; not recommended with uncontrolled hypertension (Kyzatrex (testosterone undecanoate) label) | Periodic blood pressure checks |
| Blood count | Check hemoglobin and hematocrit for polycythemia (testosterone cypionate label) | Lab follow-up schedule |
Sources: Kyzatrex (testosterone undecanoate) label; testosterone cypionate label. Accessed Oct 22, 2026.
Ask for a review of changed erections and bring your treatment history; the Viagra (sildenafil) label calls for evaluation of potential underlying ED causes. Our no morning wood guide can help you prepare questions about morning erections.
Testosterone plus Viagra or Cialis
TRT and an ED prescription can address separate needs. NIDDK treatment guide says clinicians may prescribe testosterone with PDE5 inhibitors for men with both ED and low testosterone; this is a clinical decision, not permission to combine medicines yourself (Kyzatrex (testosterone undecanoate) label; Viagra (sildenafil) label; Cialis (tadalafil) label).
The PDE5 safety rules still apply: sildenafil and tadalafil are contraindicated with organic nitrates or riociguat (Viagra (sildenafil) label; Cialis (tadalafil) label). The Viagra (sildenafil) label also says combinations with other ED treatments have not been studied and are not recommended.
Bring the exact names of everything you already take to the visit. Use our sildenafil vs tadalafil comparison to prepare questions about the options.
What each path includes
Choose the visit around the question you need answered. Use this comparison to prepare for a clinician’s assessment.
| Path | Question it addresses | What it includes | Boundary |
|---|---|---|---|
| Hormone workup and TRT | Is testosterone deficiency present? | Two early-morning blood tests plus symptoms or signs (AUA criteria summary); testosterone if deficiency is confirmed (Kyzatrex (testosterone undecanoate) label) | Fertility and blood pressure monitoring (Kyzatrex (testosterone undecanoate) label) |
| ED assessment | What is causing the erection problem? | History, medicine review, examination and tests as indicated (NIDDK) | A normal hormone result does not finish the ED assessment |
| Standalone ED prescription | Is an ED medicine suitable? | Sildenafil or tadalafil if appropriate (Viagra (sildenafil) label; Cialis (tadalafil) label) | Requires sexual stimulation; nitrate contraindication (Viagra (sildenafil) label; Cialis (tadalafil) label) |
| Mendoxa 3-in-1 visit | Does the compounded tablet fit? | Online review by Independent licensed providers; Prescription required | Mendoxa does not offer testosterone; compounded drugs are not FDA-approved |
Sources: NIH-hosted AUA criteria summary; Kyzatrex (testosterone undecanoate) label; NIDDK diagnosis; Viagra (sildenafil) label; Cialis (tadalafil) label; FDA compounding Q&A; Mendoxa product information in the ED intake. Accessed Oct 22, 2026.
Your next step
- No confirmed deficiency: ask for an ED assessment and whether morning hormone testing belongs in it.
- Confirmed deficiency plus ED: ask the hormone prescriber and ED clinician to coordinate the two treatment decisions.
- Already on TRT, erections still difficult: bring your results and medicine list to an ED assessment.
These routes follow the separate diagnostic and treatment roles described above (Kyzatrex (testosterone undecanoate) label; Viagra (sildenafil) label; NIDDK treatment guide). Mendoxa does not offer testosterone; its online ED visit lets you ask whether its compounded tablet is suitable.
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.
Give the prescriber your full medicine list, including any testosterone. See ED medication and nitrates for more detail.
If ED is the problem you want treated now
Start with the Mendoxa 3-in-1 visit to ask whether its compounded rapid-dissolve tablet fits your ED care. Independent licensed providers assess suitability; Prescription required. Mendoxa does not offer testosterone.
The tablet combines sildenafil, tadalafil and apomorphine; it is not FDA-approved. Ingredient references are the Viagra (sildenafil) label, Cialis (tadalafil) label and APOKYN (apomorphine) label; APOKYN is an injectable Parkinson’s treatment, and its label is not approval of this ED combination.
Bring your current medicines, what you have tried and any hormone results. Read about the combination ED tablet or how an online ED prescription visit works before you start. Quantities and costs appear in the table 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 22, 2026. The intake always shows the current price.
FAQ
Will TRT help ED if my testosterone is normal?
TRT is not labeled for treating ED at normal testosterone levels (Kyzatrex (testosterone undecanoate) label). The low-testosterone populations in the TRAVERSE PubMed abstract and the Testosterone Trials cannot establish benefit for men with normal levels.
Can TRT cause erectile dysfunction?
The Kyzatrex (testosterone undecanoate) label and testosterone cypionate label do not list erectile dysfunction by name, but the cypionate label lists increased or decreased libido and the Kyzatrex label warns about reduced fertility. Report any change in erections to your prescriber.
Why do I still have ED on testosterone?
Better hormone levels do not assure better erections: TRAVERSE found no erectile-function improvement versus placebo (TRAVERSE PubMed abstract). An assessment should consider underlying causes of ED (Viagra (sildenafil) label); bring your hormone results and treatment history.
Can I take Viagra or Cialis while on TRT?
Possibly, if a clinician decides both treatments are appropriate: NIDDK treatment guide describes testosterone plus PDE5 inhibitors for men with ED and low testosterone (Kyzatrex (testosterone undecanoate) label; Viagra (sildenafil) label; Cialis (tadalafil) label). Sildenafil and tadalafil remain contraindicated with nitrates or riociguat (Viagra (sildenafil) label; Cialis (tadalafil) label).
Does testosterone therapy affect fertility?
It can: the Kyzatrex (testosterone undecanoate) label says it may cause azoospermia and that the impact on fertility may be irreversible. Discuss family plans before starting.
How long does TRT take to help erections?
These trials do not establish a reliable erection-response timeline: one reported improved erectile function, while TRAVERSE did not (Testosterone Trials abstract; TRAVERSE PubMed abstract). Do not use a trial’s follow-up duration as an onset estimate; discuss expectations with the prescriber (Kyzatrex (testosterone undecanoate) label for the labeled indication).
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 rechecked the linked labels, FDA pages, NIH guidance and PubMed abstracts on Oct 22, 2026. The trial table distinguishes overall treatment results from an analysis of hormone changes within the same study; these are not three independent trials. No head-to-head comparison or response timeline is inferred. The AUA diagnostic criteria are attributed to the linked NIH-hosted clinical paper; the AUA PDF could not be independently retrieved in this pass.
Updated Oct 22, 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 22, 2026.
- DailyMed: CIALIS (tadalafil) tablet, film coated, label revised 3/2026. Accessed Oct 22, 2026.
- DailyMed: APOKYN (apomorphine hydrochloride) injection, label revised 6/2022. Accessed Oct 22, 2026.
- FDA (Drugs@FDA): VIAGRA (sildenafil) prescribing information, NDA 020895. Accessed Oct 22, 2026.
- FDA (Drugs@FDA): CIALIS (tadalafil) prescribing information, NDA 021368. Accessed Oct 22, 2026.
- FDA: Compounding and the FDA, questions and answers. Accessed Oct 22, 2026.
- DailyMed: Kyzatrex (testosterone undecanoate) label. Accessed Oct 22, 2026.
- DailyMed: testosterone cypionate label. Accessed Oct 22, 2026.
- FDA: testosterone labeling changes, February 28, 2025. Accessed Oct 22, 2026.
- Snyder PJ et al. Effects of Testosterone Treatment in Older Men. N Engl J Med 2016 (PubMed). Accessed Oct 22, 2026.
- Cunningham GR et al. Testosterone Treatment and Sexual Function in Older Men With Low Testosterone Levels. J Clin Endocrinol Metab 2016 (PubMed). Accessed Oct 22, 2026.
- Pencina KM et al. Effect of Testosterone Replacement Therapy on Sexual Function and Hypogonadal Symptoms in Men with Hypogonadism. J Clin Endocrinol Metab 2024 (PubMed). Accessed Oct 22, 2026.
- NIH-hosted clinical paper: AUA criteria in the introduction. Accessed Oct 22, 2026.
- NIDDK: treatment for ED. Accessed Oct 22, 2026.
- NIDDK: diagnosis of ED. Accessed Oct 22, 2026.
- Mendoxa ED care (product, format, max 1 dose per 24 hours). Accessed Oct 22, 2026.
- Mendoxa ED intake: plan prices (term_options). Accessed Oct 22, 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.