Sildenafil and tadalafil, with proper workup.
The most effective oral treatments for ED — sildenafil and tadalafil — prescribed with the cardiovascular and hormonal workup they actually require.
The most effective oral treatment for erectile dysfunction.
Sildenafil (Viagra) and tadalafil (Cialis) belong to a class of medications called PDE-5 inhibitors. They work by relaxing blood vessels in the penis to allow stronger, more sustained erections during sexual stimulation. Both medications have been used safely by millions of men since their FDA approval — sildenafil in 1998 and tadalafil in 2003 — and they remain the most effective and best-studied oral treatments for ED.
The two work through the same mechanism but have meaningfully different profiles. Sildenafil is a shorter-acting medication taken on demand, typically 30 to 60 minutes before sexual activity, with effects lasting 4 to 6 hours. Tadalafil is longer-acting, with effects lasting up to 36 hours from a single dose — earning it the nickname “the weekend pill” — and can also be taken as a low daily dose for continuous coverage.
For most men with ED, one of these two medications will work well. The clinical question is which one fits your situation, and what dose and protocol makes the most sense given your symptoms, frequency, and other medications. We have an honest conversation about that during the consultation rather than defaulting to a one-size-fits-all prescription.
Sildenafil, tadalafil on-demand, or daily tadalafil.
Both medications work for most men. The right choice depends on how often you want coverage, how spontaneous you want to be, and what side effect profile fits you best.
Sildenafil 50–100 mg
Taken 30 to 60 minutes before sexual activity. Works for 4 to 6 hours. The classic on-demand option — best for men who have predictable schedules or prefer a clear “this is when it works” window. Generally affordable as a generic. Common starting dose is 50 mg, adjusted up or down based on response.
Best for: Predictable timing · Lower cost · Shorter windowTadalafil 10–20 mg
Taken 30 minutes to 2 hours before sexual activity. Works for up to 36 hours from a single dose. The choice for men who want flexibility — you don’t have to time it precisely, and the window of effect spans an entire weekend. Generally well-tolerated, with slightly different side effect profile than sildenafil.
Best for: Spontaneous timing · Longer window · Weekend dosingTadalafil 2.5–5 mg daily
Low dose taken every day for continuous coverage. No advance planning required — you’re “always ready.” Particularly useful for men with more frequent intimacy, men who find on-demand dosing inconvenient, or men with concurrent BPH (benign prostatic hyperplasia), since daily tadalafil also improves urinary symptoms. Reaches steady state within about 5 days.
Best for: Frequent intimacy · BPH symptoms · Daily routineED is often a signal. Treating the cause matters as much as treating the symptom.
PDE-5 inhibitors work well for most men, but they treat the symptom rather than the underlying cause. ED can be the first noticeable sign of cardiovascular disease, hormonal imbalance, sleep apnea, or metabolic dysfunction. Smart care addresses both.
The medication makes intimacy possible. The workup tells you what needs attention.
Men who develop ED have something specific going on more often than not. We do the workup so the medication is paired with addressing the root cause — not just masking it.
- Cardiovascular screening — ED can be an early warning sign of vascular disease, addressed alongside treatment
- Testosterone evaluation — low T contributes to ED in many men; TRT is often part of the picture
- Metabolic markers — diabetes, prediabetes, and insulin resistance all affect erectile function
- For libido-specific concerns where erection mechanics work but desire isn’t there, PT-141 is a separate conversation
From consultation to first prescription, in real medicine.
Prescribing PDE-5 inhibitors thoughtfully takes more than a brief questionnaire. Here’s what the process actually looks like.
Initial consultation
In person at our Houston clinic. We discuss your symptoms, when they started, frequency, intimacy patterns, current medications, and your goals. We also screen for cardiovascular risk factors and any contraindications to PDE-5 inhibitors.
Focused workup
Comprehensive labs at LabCorp or Quest — testosterone (total, free, SHBG), thyroid, A1c and lipid panel, PSA where age-appropriate, and a baseline cardiovascular review. Sleep apnea screening if symptoms suggest it. We’re identifying the underlying contributors, not just confirming the diagnosis.
Protocol design
Your physician walks through the three options — sildenafil on-demand, tadalafil on-demand, or daily low-dose tadalafil — and recommends what fits your situation. We discuss starting dose, expected response, and any other interventions worth pairing with the medication (TRT, sleep apnea treatment, lifestyle adjustments).
First prescription
FDA-approved generic sildenafil or tadalafil filled at retail pharmacy. Both are typically affordable cash-pay even when not covered by insurance. Clear instructions on dosing, timing, and what to expect.
Follow-up & adjustment
Brief follow-up to assess response, tolerability, and any side effects. Most men find their working dose within the first month. If response is inadequate at the starting dose, we titrate up. If side effects are significant, we switch medications or adjust the protocol.
Ready to start the conversation?
A 45-minute consultation with one of our physicians. We’ll review your specific situation, walk through the medication options honestly, and decide together what fits — sildenafil, tadalafil on-demand, or daily tadalafil, with or without other clinical interventions.
What these medications can — and can’t — do.
PDE-5 inhibitors are among the most well-studied medications in modern medicine. They work for most men with ED. They also have specific limitations worth understanding before starting.
What these medications do well
- Produce reliable erections in approximately 70% of men with ED
- Well-tolerated with predictable, manageable side effect profile
- Affordable as generics — usually $1–$5 per dose
- 25+ years of real-world safety data
- Daily tadalafil also improves BPH urinary symptoms for men with both conditions
- Don’t cause dependency or withdrawal — you can use as needed and stop without issue
What they can’t do
- Produce an erection without sexual stimulation — they enable response, they don’t trigger it
- Address low libido — if the issue is desire rather than mechanics, PT-141 is a different conversation
- Be safely combined with nitrates (heart medications) — this is a real medical concern, not a theoretical one
- Fix the underlying causes of ED — if there’s testosterone, vascular, or sleep apnea involvement, those need their own attention
- Be appropriate for every patient — men with significant cardiovascular disease, retinal conditions, or certain medication interactions need careful evaluation
Before you book.
How much does treatment cost?
Generic sildenafil and tadalafil are typically $1 to $5 per dose at retail pharmacies, with daily tadalafil running about $30 to $60 per month cash-pay. Most insurance plans cover both. Our clinical service fees cover physician oversight, lab review, and follow-up separately. We’ll discuss specifics during consultation.
Sildenafil or tadalafil — which is better?
Neither is universally “better.” They work through the same mechanism with comparable efficacy. The choice depends on your situation. Sildenafil works in a clearer window (4 to 6 hours) and is slightly more affordable. Tadalafil works longer (up to 36 hours) and offers a daily-dose option. Some men respond better to one than the other for reasons that aren’t fully understood. If the first medication doesn’t work well, switching to the other is a reasonable next step.
What about side effects?
Common side effects include headache, flushing, nasal congestion, and indigestion — typically mild and short-lived. Sildenafil more often causes visual changes (blue tint, light sensitivity); tadalafil more often causes muscle aches and back pain. Both can cause low blood pressure, which is why we screen for cardiovascular history and current medications carefully. Serious side effects (priapism, sudden vision or hearing loss) are rare but warrant immediate medical attention.
Can I take these with other medications?
Generally yes, with one critical exception: nitrates (used for chest pain and certain heart conditions) are an absolute contraindication. The combination can cause severe, life-threatening drops in blood pressure. Some alpha-blockers used for blood pressure or BPH require careful timing. Certain antifungal and HIV medications interact with PDE-5 inhibitors. We review your full medication list during consultation and prescribe accordingly.
I’ve tried these before and they didn’t work. Now what?
About 30% of men don’t get adequate response to PDE-5 inhibitors. The first step is making sure the dose was correct, the timing was right, and the medication was taken on an appropriate stomach (sildenafil works better fasted; tadalafil is less affected by food). If those are addressed and response is still inadequate, the underlying cause may not be primarily vascular — testosterone, blood flow, neurological, or psychological factors may be involved. We do the workup to figure out what’s actually going on rather than just keep adjusting the prescription.
Is ED a sign of something else going on?
Often, yes. ED can be the first noticeable symptom of cardiovascular disease — sometimes appearing years before a heart event. It can also signal low testosterone, sleep apnea, diabetes, or medication side effects. This is why we do a full workup rather than just prescribing the medication. Treating ED while ignoring an underlying cause is a missed opportunity to improve your broader health.
Can I buy generic sildenafil online and skip the doctor visit?
You can, but you’d be skipping the workup that identifies what’s actually causing your ED and whether you have any conditions that make PDE-5 inhibitors unsafe. Direct-to-consumer telehealth services have made these medications very accessible, which is good for convenience but doesn’t substitute for a real clinical evaluation, especially if you’re over 50 or have any cardiovascular risk factors. The medication is the easy part. The workup is the part that matters.
Start with a conversation, not a prescription.
A 45-minute consultation with one of our Houston physicians. We’ll review your specific situation, walk through your options honestly, and decide together what fits.