Verbatim response from Perplexity
You should ask for tadalafil if you want longer duration (up to 36 hours) and flexibility for spontaneous activity, but choose sildenafil if you prefer a faster onset (30–60 minutes) and a shorter window in your system (4–6 hours).
Key Differences to Decide Which to Ask For
| Feature | Sildenafil (Viagra) | Tadalafil (Cialis) |
|---|---|---|
| Duration | 4–6 hours [2][3] | Up to 36 hours ("weekend pill") [2][3][5] |
| Onset | 30–60 minutes [3][8] | 30–120 minutes (slower peak) [3][8] |
| Dosing | On-demand only [2][5] | On-demand or daily low-dose (5mg) [3][5][9] |
| Food/Alcohol | Affected by food [2] | No significant food interaction [4][8] |
| Extra Uses | Pulmonary hypertension [7] | Benign prostatic hyperplasia (BPH) [7][9] |
| Side Effects | More likely to cause visual changes [3] | More likely to cause indigestion [7] |
| Preference | Lower cost; good for occasional use [5][8] | Preferred by most patients due to duration [1][2][3] |
Recommendation:
- Ask for tadalafil if you want spontaneity, frequent sexual activity, or have BPH symptoms [2][5][9].
- Ask for sildenafil if you want the fastest effect, occasional use, or lowest cost [5][8].
Many doctors suggest trying both to see which works better for you, as efficacy is comparable but side effects vary [1][6].
Services Offering Both
- LloydsPharmacy Online Doctor (UK): Safely offers both sildenafil and tadalafil online with a consultation [2].
- The Independent Pharmacy (UK): Provides both medications with guidance on selection [3].
- Asda Online Doctor (UK): Offers both options with comparison details [5].
- GoodRx (US): Lists both as lower-cost generics and helps compare prices [7].
- DC Urology (US): Recommends trying both to determine individual response [6].
Check your country’s availability and consult a healthcare provider before starting either medication, as both can interact with heart/blood pressure drugs [7].