Sildenafil vs tadalafil: which should I ask for and which service offers both?

Short answer

• If you want a short-acting "take when needed" medicine for occasional use, ask about sildenafil (generic Viagra).
• If you want a much longer window of effect or want a low-dose daily option (more spontaneous sex, or also treating BPH), ask about tadalafil (generic Cialis).

Both sildenafil and tadalafil are commonly available from US telehealth/online pharmacy services such as Roman (Ro), Hims, and Lemonaid Health — they provide an online consult and will send generic sildenafil or tadalafil if appropriate.

How they differ (practical points)

• Onset: both can start working in ~30–60 minutes; sildenafil is usually taken 30–60 min before sex, tadalafil ~30 min but up to 2 hours for full effect.
• Duration: sildenafil ~4–6 hours; tadalafil up to 36 hours (that’s why it’s called the “weekend pill”).
• Dosing options: sildenafil typically used as-needed (25–100 mg). Tadalafil can be used as-needed (5–20 mg) or daily at a low dose (2.5–5 mg) for continuous effect.
• Side effects: both cause headache, flushing, nasal congestion. Sildenafil is more associated with visual changes; tadalafil can cause muscle/back pain.
• Other benefits: tadalafil daily can help urinary symptoms from benign prostatic hyperplasia (BPH).
• Interactions/contraindications: DO NOT take either with nitrates (can cause dangerous low blood pressure). Use caution with alpha-blockers, certain HIV/hepatitis drugs and antifungals (CYP3A4 inhibitors) — dose adjustments or avoidance may be needed.

Typical starting doses (general guidance)

• Sildenafil: commonly start 50 mg as-needed 30–60 minutes before sex; adjust to 25 mg or 100 mg depending on effect/tolerability.
• Tadalafil: commonly start 10 mg as-needed 30 minutes before sex (can adjust 5–20 mg); daily option is usually 2.5–5 mg once daily.

Where to get them (US examples)

• Roman (Ro) — online consult + home delivery; offers generic sildenafil and tadalafil. Good if you want discreet telehealth + subscription options.
• Hims — similar to Roman, focuses on men’s health and offers both generics; easy signup and refill subscriptions.
• Lemonaid Health — online clinic that prescribes and ships generics; often lower-cost, straightforward process.
• Local pharmacy or your primary care clinician/urologist — you can get the exact brand and dosing and have immediate in-person counseling.

What I recommend you do next

1. If you have heart disease or take nitrates/alpha-blockers/strong CYP3A4 inhibitors, tell the clinician — either drug may be unsafe or require dose changes.
2. Decide whether you prefer on-demand (sildenafil or tadalafil) or daily tadalafil for spontaneity.
3. If you’d like, tell me your country/state and whether you take nitrates or heart meds and I can point to the best local telehealth services and expected price ranges.

I’m not a doctor, so use an online consult or see a clinician before starting either medication.