Tadalafil (Cialis) in Singapore: Dosage, Side Effects, Cost & Daily vs On-Demand

Medically reviewed by Dr. Kevin Chua, Medical Director

Disclaimer: This article provides general medical information and is not a substitute for professional medical advice. Tadalafil is a prescription-only medication in Singapore. Always consult a licensed doctor before use.

Introduction

Tadalafil — marketed as Cialis and available in generic forms — is a PDE5 inhibitor distinguished by its long duration of action (up to 36 hours) and the option for daily low-dose use. These features make it the preferred choice for many men who want flexibility and spontaneity in their sex lives.

This guide covers everything Singaporean men need to know about tadalafil, including the key decision between daily and on-demand dosing.

How Tadalafil Works

Like sildenafil, tadalafil inhibits PDE5 — the enzyme that breaks down cyclic GMP (cGMP) in penile smooth muscle. By blocking PDE5, tadalafil enhances the natural erectile response to sexual stimulation¹.

What makes tadalafil unique is its pharmacokinetic profile. It has a half-life of approximately 17.5 hours — far longer than sildenafil (3–5 hours) — which gives it its extended duration of action. This means a single dose can remain effective for up to 36 hours.

Sexual stimulation is still required — tadalafil does not cause spontaneous erections.

Daily vs On-Demand Dosing

Tadalafil is the only PDE5 inhibitor approved for both daily and on-demand use. Choosing between these two approaches is one of the key decisions to discuss with your doctor.

On-Demand Dosing (10–20 mg)

• Take 30–60 minutes before sexual activity
• Effects last up to 36 hours
• Maximum one dose per day
• Best for men who have sex 1–2 times per week or less

Daily Dosing (2.5–5 mg)

• Take at the same time every day, regardless of sexual activity
• Provides continuous coverage — be ready at any time
• Reaches steady-state blood levels within 5 days
• Best for men who have sex frequently or prefer not to plan

Which Should You Choose?

Dosage Guide

Tips for Best Results

• Food does not significantly affect absorption — take with or without meals
• For on-demand use, some men find taking it 2 hours before activity gives peak effect
• Allow 4–6 attempts before concluding a dose is ineffective
• For daily dosing, take at a consistent time to maintain steady blood levels

Side Effects

Tadalafil's side effect profile differs slightly from sildenafil due to its longer half-life and selectivity for certain PDE5 subtypes.

Common Side Effects

• Headache — the most frequent side effect
• Back pain and myalgia — more common with tadalafil than sildenafil; typically appears 12–24 hours after dosing and resolves within 48 hours
• Nasal congestion
• Dyspepsia
• Facial flushing — less common than with sildenafil

With Daily Dosing

Side effects tend to be milder and less frequent at steady state, as the daily dose (2.5–5 mg) is much lower than on-demand doses (10–20 mg).

Rare but Serious Side Effects

• Priapism — an erection lasting more than 4 hours. Seek emergency care immediately
• Sudden vision or hearing changes — discontinue and seek medical attention

Tadalafil and BPH

An additional benefit of daily tadalafil (5 mg) is its efficacy in treating symptoms of benign prostatic hyperplasia (BPH) / lower urinary tract symptoms (LUTS). For men with both ED and BPH, daily tadalafil can address both conditions with a single medication¹.

Common BPH/LUTS symptoms that may improve include:

• Frequent urination (especially at night)
• Weak urine stream
• Difficulty starting urination
• Incomplete bladder emptying

Contraindications and Interactions

Absolute Contraindications

• Nitrate medications — risk of severe, life-threatening hypotension¹
• Recent cardiovascular event (within 6 months)
• Severe hepatic impairment (Child-Pugh C)
• Hypotension (BP <90/50 mmHg)

Drug Interactions

• Alpha-blockers — use lowest tadalafil dose; monitor for postural hypotension
• CYP3A4 inhibitors (ketoconazole, ritonavir) — maximum tadalafil 10 mg per 72 hours
• Antihypertensives — additive blood pressure lowering possible; monitor

Cost of Tadalafil in Singapore

Prices are approximate and may vary by provider. Updated April 2026.

For daily dosing, monthly costs range from approximately S$150–450 depending on brand vs generic.

How to Get Tadalafil in Singapore

Tadalafil is a prescription-only medication regulated by the HSA. Through noah™, the process is straightforward:

1. Complete an online health questionnaire
2. Doctor review and consultation (if needed)
3. Prescription issued if clinically appropriate
4. Discreet delivery to your door

→ See also: Online ED Consultation in Singapore (SG-N-ED-05)

FAQ

1. Can I switch from sildenafil to tadalafil?

Yes. Your doctor can help you transition. There's no need for a washout period — simply stop sildenafil and begin tadalafil. Many men try both to see which they prefer.

2. Does tadalafil work immediately on the first dose?

Many men notice effects within 30–60 minutes of the first dose. For daily dosing, steady-state levels (and optimal effect) are reached in about 5 days. Give it 4–6 attempts before concluding it doesn't work.

3. Is the 36-hour window real?

Yes, but individual results vary. Most men report reliable effects for 24–36 hours. This doesn't mean you'll have an erection for 36 hours — it means you can achieve an erection with sexual stimulation within that window.

4. Can I drink alcohol with tadalafil?

Moderate alcohol consumption is generally compatible with tadalafil. However, excessive alcohol worsens ED and increases the risk of side effects (dizziness, low blood pressure). Keep it to 1–2 standard drinks.

5. Is daily tadalafil safe long-term?

Long-term studies of daily tadalafil (up to 2 years) have demonstrated a consistent safety profile with no emerging safety concerns¹. Many men use daily tadalafil as an ongoing treatment.

References

→ Return to pillar: Complete Guide to ED Treatment in Singapore

This article is for informational purposes only and does not constitute medical advice. Always consult a licensed doctor before starting any treatment. noah™ consultations are conducted by SMC-registered doctors in accordance with MOH telemedicine guidelines.