ED Treatment for Diabetics 2026: What Works, What’s Safe, and Which Telehealth Service Is Best

Last updated May 27, 2026 · Medically reviewed by Dr. Marcus Tan, MD · ~10 min read

Erectile dysfunction affects about half of men with diabetes. PDE5 inhibitors — sildenafil (the generic of Viagra), tadalafil (the generic of Cialis), and compounded combinations like Ro Sparks — work in roughly 70–80% of diabetic men. Daily tadalafil at 2.5–5 mg is often the preferred starting choice because it preserves spontaneity and may improve endothelial function with continuous dosing. The single most important safety check before starting any ED medication with diabetes is screening for nitrate co-prescription, which is an absolute contraindication.

Among telehealth services, Ro is our recommended platform for diabetic men with ED. Its asynchronous intake explicitly screens for nitrate use (the critical safety filter many platforms gloss over), it offers all four PDE5 inhibitors plus its sublingual Sparks formulation, and its daily tadalafil plan starts at about $21/month — often the best-value protocol for a diabetic patient who wants to dose consistently rather than on demand. Hims is a strong second; BlueChew works for diabetics who want a chewable but offers fewer dosing options.

ED and diabetes: why it’s so common (and what’s actually happening)

Erectile dysfunction affects approximately 50% of men with diabetes — roughly double the rate in age-matched non-diabetic men. The reason isn’t a single broken pathway; it’s that diabetes damages four of the systems an erection depends on simultaneously. Understanding which mechanism is dominant in your case matters, because it determines which treatments work best and which won’t.

Diabetic ED is typically multifactorial, driven by some combination of:

1. Vascular damage. Chronic hyperglycemia damages both small blood vessels (microvascular) and large ones (macrovascular). An erection requires roughly seven times normal blood flow into the penis; if the vasculature is compromised, the hydraulic system fails. This is why diabetic ED is often a sentinel symptom for coronary artery disease.
2. Autonomic neuropathy. Erections require intact parasympathetic nerve signaling to trigger nitric oxide release. Diabetic neuropathy damages these nerves alongside the more familiar peripheral neuropathy that affects feet.
3. Hypogonadism. About 30% of diabetic men have clinically low testosterone, which depresses libido and erectile response. Insulin resistance and obesity both suppress the HPG axis.
4. Psychological factors. Major depressive disorder is roughly twice as common in diabetes; SSRIs prescribed for it can themselves cause ED. Performance anxiety on top of an underlying vascular problem compounds the issue.

The clinical implication: PDE5 inhibitors fix the vascular and partially the neuropathic component, which is why they work in 70–80% of diabetic men — not 100%. If your testosterone is low, or if depression is driving things, a PDE5 inhibitor alone may not be enough. A good telehealth clinician will ask about libido, mood, and morning erections to triage which mechanism dominates.

Is sildenafil safe for diabetics? (the data)

Yes — sildenafil (the active ingredient in generic Viagra) has been studied in diabetic men in more than 20 randomized controlled trials since its 1998 approval. It is one of the most extensively evaluated medications in this population. The headline result: sildenafil produces erections sufficient for intercourse in roughly 70–75% of diabetic men, compared to placebo response rates of 10–15%.

Effectiveness is modestly lower than in non-diabetic men (where response rates run 80–90%) because of the underlying vascular damage discussed above — sildenafil can’t fix a blood vessel that’s already been damaged by years of hyperglycemia, it can only amplify the signal in vessels that still respond. The longer and worse-controlled your diabetes has been, the less likely sildenafil will produce a strong response.

Practical dosing for diabetic men:

• Starting dose: 50 mg, taken 30–60 minutes before sex on an empty stomach (a high-fat meal blunts absorption by ~30%)
• Titration: If 50 mg is inadequate, 100 mg is the standard next step. Most diabetic men who respond need 100 mg rather than 50 mg.
• Onset: 30–60 minutes
• Duration: 4–6 hours
• Max frequency: Once per 24 hours

If diabetic gastroparesis (delayed gastric emptying, present in roughly 30–50% of long-standing diabetics) is part of your picture, oral sildenafil absorption can be erratic. In that subgroup, sublingual options like Ro Sparks may be a better fit because they bypass the stomach entirely. See our sildenafil vs tadalafil for ED breakdown for a deeper head-to-head.

Is tadalafil safe for diabetics? (and why daily dosing often wins)

Tadalafil (the active in generic Cialis) is just as safe in diabetic men as sildenafil, and for several practical reasons it’s often the better choice. The on-demand version (10 mg or 20 mg) works in 70–80% of diabetic men with the same effectiveness profile as sildenafil, but lasts considerably longer.

The bigger story is daily low-dose tadalafil (2.5–5 mg every day), which is often the protocol best suited to diabetic men. Three reasons:

1. Spontaneity. You don’t time a pill around sex; you’re always ready. For couples, this often matters more than the pharmacology.
2. Endothelial function. Small but consistent evidence suggests continuous PDE5 inhibition modestly improves endothelial function over weeks of dosing — potentially relevant in a population whose endothelium is the underlying problem.
3. BPH co-treatment. Tadalafil is FDA-approved for benign prostatic hyperplasia, which is common in older diabetic men. One pill, two problems.

On-demand tadalafil specifics: 10 mg or 20 mg, onset 30–45 minutes, duration up to 36 hours (the “weekend pill” reputation). Less affected by food than sildenafil.

Daily tadalafil specifics: 2.5 mg starting (often titrated to 5 mg if needed), taken at the same time each day. Steady-state plasma levels in about 5 days. Ro’s daily tadalafil plan at approximately $21/month is among the most cost-effective protocols on the market for a diabetic man who has sex more than twice a week.

Drug interactions: what’s safe and what’s not with diabetes meds

The good news for most diabetic men: PDE5 inhibitors don’t meaningfully interact with the medications that actually treat diabetes. The danger isn’t your A1c-lowering drugs; it’s the cardiovascular medications that often ride along with diabetes, especially nitrates. Here’s the drug-by-drug breakdown.

Metformin

Safe. No clinically meaningful interaction between metformin and sildenafil, tadalafil, vardenafil, or avanafil. They are metabolized through entirely different pathways — metformin is renally cleared without significant CYP involvement, while PDE5 inhibitors are hepatic CYP3A4 substrates. You can take your metformin on its usual schedule and dose PDE5 inhibitors without any timing adjustment. This is the most common diabetes drug, and it’s the easiest combination.

Sulfonylureas (glipizide, glyburide, glimepiride)

Safe, with a note. No direct pharmacokinetic interaction with PDE5 inhibitors. The practical caveat: sulfonylureas can cause hypoglycemia, and alcohol — often consumed before sex — potentiates that hypoglycemia. If you’re on a sulfonylurea and you drink before sex, you have two reasons to feel lightheaded (alcohol-potentiated hypoglycemia and PDE5-induced mild vasodilation). Eat something before sex and keep glucose tabs nearby. This isn’t a drug interaction; it’s a behavioral one.

Insulin

Safe. No interaction. Whether you’re on basal insulin (glargine, degludec), prandial insulin (lispro, aspart), or a pump, PDE5 inhibitors do not affect insulin pharmacokinetics or insulin sensitivity. Dose your insulin as prescribed and treat your ED separately. The only practical note: sex is exercise, and exercise can lower blood glucose; if you tend to drop with activity, the usual precautions apply.

SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin)

Safe. No clinically significant interaction with PDE5 inhibitors. SGLT2 inhibitors can cause mild volume depletion in some patients (they’re glucose-driven diuretics), and PDE5 inhibitors cause mild vasodilation; in theory you could see modest additive hypotension, but in practice this almost never matters clinically. If you’ve recently started an SGLT2 inhibitor and feel lightheaded standing up, mention it to your telehealth clinician before pushing PDE5 dose upward.

GLP-1 agonists (semaglutide, tirzepatide, liraglutide)

Safe. No direct interaction between GLP-1 receptor agonists and PDE5 inhibitors. This matters because a huge fraction of diabetic men are now on Ozempic (semaglutide), Mounjaro (tirzepatide), or Wegovy — and the question comes up constantly in telehealth intakes. The one thing worth knowing: GLP-1 agonists slow gastric emptying. If you take oral sildenafil after a high-fat meal on a GLP-1, absorption may be slower than expected and onset can drift toward 90 minutes rather than 30. Take sildenafil on an empty stomach, or use tadalafil (less food-sensitive), or use a sublingual format if this is consistently a problem.

Statins (atorvastatin, rosuvastatin, simvastatin)

Safe. No clinically significant interaction. Both statins and PDE5 inhibitors are CYP3A4 substrates in theory, but at standard doses there is no meaningful competition. In fact, statin therapy in diabetic men with ED is associated with improved erectile function over time, presumably because statins improve endothelial function. Stay on your statin.

The critical safety question: nitrates and ED meds

This is the one absolute rule, and the one most likely to come up in diabetic men because cardiovascular disease tracks with diabetes. If you take any form of nitrate — nitroglycerin tablets, nitroglycerin spray, nitroglycerin patches, isosorbide mononitrate, isosorbide dinitrate, or amyl nitrite (“poppers”) — you must not take a PDE5 inhibitor. The combination causes profound, life-threatening hypotension and has killed patients.

The mechanism is simple: both drug classes work by raising cyclic GMP. Nitrates donate nitric oxide, which produces cGMP; PDE5 inhibitors block the enzyme that degrades cGMP. Take them together and cGMP accumulates without ceiling, smooth muscle in every blood vessel relaxes, and blood pressure crashes. There is no safe time interval that resolves this for daily nitrate users; for occasional nitrate users (e.g., someone who carries nitroglycerin for angina but rarely uses it), the standard guidance is that sildenafil clears in 24 hours and tadalafil clears in 48–72 hours, and nitrates should be avoided for those windows.

The same rule applies to riociguat (Adempas), a guanylate cyclase stimulator used for pulmonary hypertension. Less common, but worth flagging.

Alpha-blockers (tamsulosin, doxazosin, alfuzosin, terazosin) — common in older diabetic men with BPH — are not an absolute contraindication, but caution and staggered dosing are required. The usual approach: stabilize on the alpha-blocker first, then add the PDE5 inhibitor at the lowest dose, taken at least four hours apart, and titrate up only if blood pressure tolerates it.

This is exactly why we recommend Ro for diabetic men: its asynchronous intake explicitly asks about nitrate use and alpha-blocker use. A surprising number of telehealth services bury this question or ask it in a way that lets patients gloss past it.

What about compounded ED medications like Ro Sparks?

Compounded sildenafil-tadalafil combinations — Ro Sparks review, Hims Hard Mints, BlueChew Max — are generally appropriate for diabetic men, with one specific advantage. The active ingredients are the same PDE5 inhibitors with the same safety profile in diabetes; the formulation is what differs. See our compounded ED medications 503A guide for the regulatory backdrop.

The diabetes-specific reason to consider a sublingual format like Ro Sparks: diabetic gastroparesis. Roughly 30–50% of long-standing diabetics have measurable delays in gastric emptying, and a subset have symptomatic gastroparesis severe enough to make oral medication absorption unpredictable. A sublingual tablet bypasses the stomach entirely — the drug enters the systemic circulation directly through the oral mucosa — producing more reliable onset (roughly 15 minutes) and more consistent peak levels.

Caveats that apply to compounded products in general also apply for diabetic men: these are not FDA-approved as finished products (the individual active ingredients are FDA-approved, but the combined sublingual tablet is not), there’s batch-to-batch variability inherent to compounding, and the regulatory environment is in flux. The Ro Sparks vs Hims Hard Mints comparison goes deeper on the trade-offs.

Our take: if you’re a diabetic man without gastroparesis, start with FDA-approved generic tadalafil (daily) or sildenafil (on-demand). If gastroparesis is part of your picture or oral absorption has been inconsistent, a sublingual compounded option is reasonable.

Best telehealth service for diabetic men with ED (and why)

We rank platforms on three diabetes-specific axes: (1) does the intake explicitly screen for nitrates and alpha-blockers, (2) does it offer the full PDE5 lineup including a daily tadalafil option, and (3) is the pricing competitive on the protocol most diabetic men do best on. Full breakdown of the broader category in our best online ED treatment services guide.

Ro (recommended)

Ro is our top pick for diabetic men with ED. Three reasons:

• Intake explicitly screens for nitrates. The question is asked clearly and the workflow blocks prescribing if the answer is yes — not buried in a checklist.
• Full PDE5 lineup plus Sparks. Generic sildenafil, generic tadalafil (on-demand and daily), vardenafil, avanafil, and the Ro Sparks sublingual compound. If one molecule isn’t working, you can pivot without switching platforms.
• Daily tadalafil at ~$21/month. This is competitive on the protocol most diabetic men actually do best on. On-demand pricing is also reasonable, but the daily plan is where Ro shines.

Workflow: asynchronous intake (~10 minutes), clinician review within 24 hours, free shipping, discreet packaging. See the Ro provider profile for full pricing detail.

See Ro pricing for diabetic ED →

Hims

Hims is a strong second. The full PDE5 lineup is there, the Hims Hard Mints compounded option is competitively priced (often the cheapest sublingual combo on the market), and the platform is polished. The reason it’s second and not first: the intake’s nitrate screening is less explicit than Ro’s — the question is asked but framed in a way that a hurried patient could under-report. For most diabetic men this is fine because they know they’re not on nitrates, but for the patient who isn’t sure, Ro’s workflow is safer.

See Hims ED pricing →

BlueChew

BlueChew is the chewable option — sildenafil or tadalafil in a soft tab format. The format is genuinely useful for men who don’t like swallowing pills, and it’s reasonable in diabetic men. Limitations: dose options are narrower than Ro or Hims (you can’t easily get a 100 mg sildenafil dose if 50 mg isn’t enough), no avanafil or vardenafil, no Sparks-style sublingual combo. Good for a straightforward case; less flexible if titration is needed.

See BlueChew pricing →

When PDE5 inhibitors don’t work: second-line options

Roughly 20–30% of diabetic men don’t get an adequate response from any PDE5 inhibitor — usually because vascular damage is severe, autonomic neuropathy is advanced, or both. If you’ve tried sildenafil at 100 mg and tadalafil at 20 mg (or daily 5 mg for at least two weeks) and haven’t gotten useful erections, you have three real options.

Alprostadil. A prostaglandin E1 analogue that produces erection by direct smooth muscle relaxation, independent of nitric oxide signaling. Two delivery formats:

• Intracavernosal injection (Caverject, Edex): a small needle into the side of the penis 5–15 minutes before sex. Sounds worse than it is — the needle is fine and the technique is quickly learned. Effectiveness in diabetes is excellent (~80% response). Main downsides: occasional pain, risk of priapism, learning curve.
• Intraurethral suppository (MUSE): a small pellet inserted into the urethra. Less effective than injection (~40–50% in diabetes) but no needle.

Vacuum erection device (VED). A mechanical pump that draws blood into the penis; a constriction ring at the base holds the erection. Works in any man with intact corporal bodies regardless of vascular status, which makes it particularly useful in diabetic men with severe vascular disease. Inexpensive (~$200–500 one-time) and covered by Medicare. The erection feels different from a physiologic one (hinged at the base, cooler), but functions adequately.

Penile implant. Last resort, but the satisfaction data in diabetic men is striking — patient and partner satisfaction rates routinely exceed 90%, the highest of any ED treatment. A urologic procedure under general anesthesia; recovery 4–6 weeks. Telehealth can’t get you here; you’ll need an in-person urology referral. If you’ve exhausted PDE5 inhibitors and don’t want injections, this is worth a conversation with a urologist.

Lifestyle changes that genuinely help diabetic ED

The lifestyle conversation in ED is often vague and moralizing. Here’s what the data actually supports specifically in diabetic men, ranked by effect size.

1. Weight loss of 5–10% of body weight. The single highest-yield intervention. Improves insulin sensitivity, raises testosterone, improves endothelial function, reduces inflammation. Pre/post studies in obese diabetic men show roughly 30–40% improvement in IIEF erectile function scores with sustained 7–10% weight loss. GLP-1 agonists make this newly achievable for many patients.
2. Glycemic control (A1c reduction). Tighter control slows the progression of microvascular damage. It won’t reverse damage already done, but it preserves what’s still working. Aim for individualized A1c targets — usually <7% but lower may be appropriate depending on age and comorbidities.
3. Regular aerobic exercise. 150 minutes/week of moderate aerobic activity improves endothelial function and erectile response in diabetic men in multiple RCTs. The effect is real but smaller than weight loss.
4. Smoking cessation. Smoking compounds diabetic vascular damage. Quitting won’t reverse damage already done but stops the trajectory.
5. Sleep apnea treatment. Often overlooked. Untreated OSA suppresses testosterone and worsens vascular function. If you snore loudly, wake unrefreshed, or your partner notices apneic pauses, get a sleep study.
6. Limit alcohol. Heavy alcohol use suppresses testosterone and impairs erection acutely. Moderate use is fine.

How to talk to your telehealth provider about diabetic ED

A 10-minute telehealth intake can only do so much if the patient isn’t forthcoming. To get the right prescription on the first try, surface this information up front:

• Type and duration of diabetes. Type 1 vs type 2, years since diagnosis. Long-duration diabetes implies more vascular damage and informs dose expectations.
• Most recent A1c. If it’s been >9 for years, response will be more variable.
• Complete medication list. Especially nitrates, alpha-blockers, alpha-blockers for BPH, and any cardiac medications. Don’t omit “as-needed” medications — nitroglycerin tablets carried “just in case” still count.
• Cardiac history. Prior MI, stents, bypass, angina, heart failure. PDE5 inhibitors are generally safe but timing matters after acute events.
• Symptoms beyond ED. Low libido, fatigue, poor morning erections — these may point to hypogonadism that needs its own workup.
• What you’ve tried before. If sildenafil 100 mg didn’t work, say so; the clinician will go to tadalafil rather than re-prescribing the same molecule.
• Gastroparesis symptoms. Early satiety, nausea, bloating — if these are present, a sublingual format may be worth raising explicitly.

Frequently Asked Questions

Can diabetics take Viagra safely?

Yes, with the standard contraindications. Sildenafil (the generic of Viagra) has been studied in more than 20 RCTs in diabetic men and is the most extensively evaluated ED treatment in this population. It works in 70–75% of diabetic men. The hard rule is no concurrent nitrates — the combination causes life-threatening hypotension. Otherwise, sildenafil does not meaningfully interact with metformin, insulin, sulfonylureas, GLP-1 agonists, SGLT2 inhibitors, or statins, and standard 50 mg starting doses apply. If 50 mg is inadequate, 100 mg is the standard next step, and most diabetic men who respond do so at 100 mg rather than 50 mg.

Does metformin interact with sildenafil or tadalafil?

No. Metformin and PDE5 inhibitors are metabolized through entirely different pathways — metformin is renally cleared without significant CYP involvement, while sildenafil and tadalafil are hepatic CYP3A4 substrates. There is no clinically meaningful interaction, no need to time the doses apart, and no need to adjust either medication. Take metformin on its usual schedule and dose your PDE5 inhibitor independently. This is the most common diabetes drug, and it’s the easiest combination.

Is it safe to take ED medication with Ozempic or Mounjaro?

Yes. There is no direct pharmacokinetic interaction between GLP-1 receptor agonists (semaglutide as Ozempic or Wegovy, tirzepatide as Mounjaro or Zepbound, liraglutide as Victoza) and sildenafil, tadalafil, vardenafil, or avanafil. The one practical wrinkle is that GLP-1 agonists slow gastric emptying, which can delay onset of oral sildenafil — you may find it works in 60–90 minutes rather than the usual 30–60. Workarounds: take sildenafil on an empty stomach, use tadalafil (less food-sensitive), or use a sublingual format like Ro Sparks. The combination is otherwise safe.

Why doesn’t sildenafil work for some diabetic men?

Roughly 20–30% of diabetic men don’t get an adequate response, usually for one of three reasons. First, severe vascular damage — if the blood vessels supplying the penis are heavily atherosclerotic, PDE5 inhibition can’t restore flow that the plumbing won’t allow. Second, advanced autonomic neuropathy — if the nerves that signal nitric oxide release are damaged, there isn’t enough cGMP being produced for the PDE5 inhibitor to amplify. Third, undiagnosed hypogonadism — low testosterone depresses libido and erectile response independently of the PDE5 pathway. The fix depends on which mechanism dominates: tadalafil and titration up to 100 mg sildenafil first, then testosterone testing, then second-line options like alprostadil or vacuum devices.

Is daily tadalafil better than sildenafil for diabetes?

Often, yes. Three reasons specific to diabetic men favor daily low-dose tadalafil (2.5–5 mg/day). First, you don’t have to time dosing around sex, which restores spontaneity — valuable for couples and reduces performance anxiety. Second, continuous PDE5 inhibition may modestly improve endothelial function over weeks of dosing, which is potentially relevant when endothelial dysfunction is the underlying problem. Third, tadalafil is FDA-approved for BPH, which is common in older diabetic men — one pill treats both. The main reason to prefer sildenafil instead: cost (sildenafil is cheaper per dose if you only have sex once or twice a week) or if you’ve previously responded well to sildenafil and don’t want to change.

Can I take ED medication if I’m on insulin?

Yes. Insulin does not interact with sildenafil, tadalafil, vardenafil, or avanafil. Whether you’re on basal insulin (glargine, degludec), prandial insulin (lispro, aspart, glulisine), an insulin pump, or a combination regimen, PDE5 inhibitors do not affect insulin pharmacokinetics or change your insulin requirements. Continue dosing insulin as prescribed and treat your ED independently. The only practical note: sex is exercise, and exercise can lower blood glucose — if you tend to drop with activity, take your usual precautions (have a snack available, check glucose if you feel symptomatic).

Are Ro Sparks safe for diabetics?

Generally yes, with the same caveats that apply to any compounded ED medication. The active ingredients in Ro Sparks are sildenafil and tadalafil — the same PDE5 inhibitors that have been extensively studied in diabetic men. The sublingual format may actually be advantageous if you have diabetic gastroparesis, because the drug bypasses delayed gastric emptying and absorbs through the oral mucosa directly. The standard contraindications still apply: no nitrates, caution with alpha-blockers, screen for cardiac stability. The non-diabetes-specific caveat: Ro Sparks is compounded and not FDA-approved as a finished product, so there’s inherent batch-to-batch variability. See our Ro Sparks review for the full breakdown.

What ED treatment is best if I take nitrates?

Not a PDE5 inhibitor — that combination is an absolute contraindication and can cause fatal hypotension. If you’re on daily nitrate therapy (isosorbide mononitrate, isosorbide dinitrate, or a nitroglycerin patch), your options are non-PDE5 approaches: a vacuum erection device (mechanical, works regardless of medications), alprostadil (intracavernosal injection or intraurethral suppository, uses a different signaling pathway), or a penile implant. If you only carry nitroglycerin “as needed” for angina and rarely use it, a conversation with your cardiologist about whether you still need it — or whether your angina has been stable enough to come off it — may open the door to PDE5 inhibitors. Don’t make that decision yourself.

Does losing weight help diabetic ED?

Yes, more than almost any other lifestyle intervention. Sustained weight loss of 5–10% of body weight in obese diabetic men is associated with roughly 30–40% improvement in validated erectile function scores (IIEF), driven by improved insulin sensitivity, higher testosterone, better endothelial function, and lower systemic inflammation. The newly achievable angle in 2026 is that GLP-1 agonists (semaglutide, tirzepatide) have made this magnitude of weight loss feasible for many patients who couldn’t sustain it through lifestyle alone. Weight loss won’t replace a PDE5 inhibitor in established diabetic ED, but it stacks with it — many men find the same dose works better after losing 20 pounds.

Is online ED treatment safe if I have diabetes?

Yes — with the right service. Telehealth is well-suited to diabetic ED because the prescribing decision is largely driven by medication history (especially nitrates and alpha-blockers), past PDE5 response, and a few specific questions. The key is picking a platform whose intake actually screens for the contraindications that matter in a diabetic population, rather than rubber-stamping a prescription. Ro is our recommended choice because its intake explicitly asks about nitrate use and blocks prescribing if the answer is yes; Hims is a strong second. Avoid platforms that don’t ask about nitrates, don’t ask about your cardiac history, or don’t ask about other prescriptions — those shortcuts are how patients get hurt. With a careful platform, online ED treatment for diabetic men is safe, convenient, and often better than an in-office visit because the asynchronous workflow gives you time to answer accurately.

Sources

• Malavige LS, Levy JC. Erectile dysfunction in diabetes mellitus. Journal of Sexual Medicine. 2009;6(5):1232–1247. (Foundational review of prevalence and mechanisms.)
• Rendell MS, Rajfer J, Wicker PA, Smith MD. Sildenafil for treatment of erectile dysfunction in men with diabetes: a randomized controlled trial. JAMA. 1999;281(5):421–426. (Original RCT establishing sildenafil efficacy in diabetes.)
• Saenz de Tejada I, Anglin G, Knight JR, Emmick JT. Effects of tadalafil on erectile dysfunction in men with diabetes. Diabetes Care. 2002;25(12):2159–2164.
• American Diabetes Association. Standards of Medical Care in Diabetes — 2026. Diabetes Care. 2026;49(Suppl 1). (Sexual dysfunction section, screening recommendations.)
• FDA prescribing information: sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), avanafil (Stendra). Drug interactions and contraindications sections.
• Kostis JB, Jackson G, Rosen R, et al. Sexual dysfunction and cardiac risk (the Second Princeton Consensus Conference). American Journal of Cardiology. 2005;96(2):313–321. (Cardiac safety guidance for PDE5 inhibitors.)
• Hackett G. The burden and extent of comorbid conditions in patients with erectile dysfunction. International Journal of Clinical Practice. 2009;63(8):1205–1213.
• Esposito K, Giugliano F, Di Palo C, et al. Effect of lifestyle changes on erectile dysfunction in obese men: a randomized controlled trial. JAMA. 2004;291(24):2978–2984.
• American Urological Association. Erectile Dysfunction: AUA Guideline. 2018 (amended 2024).
• Ro clinical workflow documentation, accessed May 2026.