Private ED care · Bangkok

Tadalafil vs sildenafil: which ED treatment fits you?

Compare the two ingredients by timing, duration, meals, side effects and treatment pattern.

The short answer

Tadalafil offers a response window of up to 36 hours and can be prescribed daily or as-needed. Sildenafil usually offers a shorter window of several hours and is generally used when needed. Neither is universally better; your health, preferences and response guide the choice.

Compare sildenafil and tadalafil

Sildenafil and tadalafil at a glance
What matters to youSildenafilTadalafil
Kauri brandsSidegra, ViagraTalafil, Casey
Planning a doseCommonly around 1 hour before sexAs-needed treatment: from around 30 minutes
Response windowSeveral hours, commonly around 4 hoursUp to 36 hours
MealsA large or fatty meal can delay the onsetFood has little effect on absorption
Treatment patternUsually when neededAs-needed or a prescribed low-dose daily plan
StimulationSexual stimulation is needed with either medicine

What is the difference in timing?

Sildenafil is commonly planned around 1 hour before sex and offers a shorter response window. As-needed tadalafil can begin helping from around 30 minutes and may remain effective for up to 36 hours. Neither medicine creates an automatic erection. The longer window may make timing easier, while a shorter window may fit someone who prefers planned, occasional treatment.

How do meals and daily use affect the choice?

A large or fatty meal can delay sildenafil; food has little effect on tadalafil absorption. Tadalafil also has a low-dose daily treatment option for selected patients. Sildenafil is usually taken when needed. A daily plan and an as-needed plan use different instructions, so compare the overall treatment pattern rather than choosing by tablet strength alone.

Do their side effects differ?

Both can cause headache, indigestion, flushing, nasal congestion or dizziness. Back or muscle aches are associated with tadalafil, while temporary visual changes can occur with sildenafil. A longer-acting medicine can also mean adverse effects take longer to settle. Tell Kauri about previous side effects so they can be considered when choosing or adjusting treatment.

Which option is right for my health and routine?

The doctor considers your medication list, cardiovascular health, kidney and liver function, previous response and preference about timing. There is no direct milligram-for-milligram conversion between these medicines. If one does not help, a review can clarify use, dose and underlying causes before a switch. Do not alternate or combine them without a clear prescribing plan.

Side effects: what should I know?

ED tablets are well tolerated by many patients. Headache, flushing, indigestion, nasal congestion and dizziness can occur. Sildenafil may cause temporary visual changes; tadalafil may cause back or muscle aches. Tell Kauri about troublesome effects so your treatment can be reviewed.

Who needs a medication review first?

Never combine these medicines with nitrates, poppers or riociguat. Tell your physician about heart symptoms, low blood pressure, kidney or liver conditions, eye problems and all other medicines, including alpha-blockers. Do not combine ED tablets yourself. Seek urgent care for an erection lasting 4 hours or longer, sudden vision or hearing loss, or chest pain; tell the treating team what you took and when. Do not self-administer nitrates after an ED medicine.

Private ED care at BTS Punnawithi, Bangkok

At Kauri, we review your symptoms, current medicines, previous response and preferences, then explain suitable treatment and follow-up. Relevant blood testing or specialist referral can be arranged when needed. Visit Kauri Health Clinic at BTS Punnawithi, 3063 Sukhumvit Rd, Bang Chak, Phra Khanong, Bangkok 10260. We are open Tuesday–Saturday, 9:00–18:00, and closed Sunday and Monday.

Patient questions

Tadalafil vs sildenafil: frequently asked questions

Which lasts longer: tadalafil or sildenafil?

Tadalafil generally has the longer response window, up to 36 hours. Sildenafil usually supports a response for several hours. Sexual stimulation is required with both; these are not continuous-erection durations.

Is tadalafil 20 mg equivalent to sildenafil 100 mg?

No direct milligram-for-milligram equivalence applies. They are different medicines with different duration and dosing instructions. Your clinician chooses the appropriate dose for each.

Which works better for older adults or people with diabetes?

Age or diabetes alone does not determine the best choice. Both medicines can be considered for appropriate patients, with the decision based on health, other medicines, response and tolerability.

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Medication and comparison guides

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Medical sources

Medicine information draws on public clinical guidance. Pack details and prices are supplied by Kauri. Content updated 16 October 2026.

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