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

Short answer

• Both are effective. Ask for the one that fits how often and how spontaneously you want sex to be:
  • Choose sildenafil (Viagra/generic sildenafil) if you want a shorter-acting option for use on-demand (works for a few hours).
  • Choose tadalafil (Cialis/generic tadalafil) if you want a long window of effect (up to 36 hours) or a daily low-dose option (good if you have frequent activity or also have BPH symptoms).

Key differences (quick)

• Onset: both ≈30–60 minutes (individual varies).
• Duration: sildenafil ~4–6 hours; tadalafil up to 36 hours.
• Dosing: sildenafil usually 25–100 mg PRN; tadalafil 5–20 mg PRN or 2.5–5 mg daily.
• Food: high‑fat meals can slow sildenafil; tadalafil is less affected by food.
• Side effects: headache, flushing, nasal congestion, dyspepsia. Visual changes more often reported with sildenafil; muscle/back ache sometimes with tadalafil.
• Interactions/contraindications: DO NOT take either with nitrates (absolute contraindication). Use caution with alpha‑blockers, some heart medicines, and strong CYP3A4 inhibitors. If you have recent heart attack/stroke or unstable heart disease, talk to your doctor first.

Which should you ask for?

• If you want occasional use and prefer a shorter window: ask for sildenafil (generic or Viagra).
• If you want more spontaneity over a day or prefer a daily low-dose option (or have BPH): ask for tadalafil (Cialis or generic).
• Cost-wise, generics for both are inexpensive—ask your clinician or pharmacy for the generic.

Where to get them (legitimate services)

• United States: Hims, Roman (Ro), and Nurx — each provides online visits and can prescribe and ship generic sildenafil or tadalafil. You can also use telemedicine services like PlushCare or GoodRx’s prescription-filling options to compare prices at local pharmacies.
• United Kingdom/Europe: Zava and Lloyds Pharmacy Online Doctor offer both sildenafil and tadalafil after an online consultation.
• If you prefer an in-person route, most community pharmacies will fill a prescription from your doctor.

Next steps

• Tell me your country and whether you take nitrates or have heart disease, and I can recommend the best service in your area and a likely starting dose to discuss with the clinician.