“Sildenafil”: options and how to choose the right one

Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Sildenafil is a prescription medication in many countries. Always consult a qualified healthcare professional before starting, stopping, or changing any treatment.

Who needs it and what goals are common

Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor most commonly prescribed for erectile dysfunction (ED). In specific formulations and doses, it is also used for pulmonary arterial hypertension (PAH).

Common goals patients have:

• Improve ability to achieve and maintain an erection sufficient for sexual activity
• Increase confidence and reduce performance anxiety
• Restore sexual function after medical conditions (diabetes, cardiovascular disease, prostate surgery)
• Address ED related to stress, mild depression, or relationship factors

ED can be multifactorial: vascular, neurological, hormonal, medication-induced, or psychological. Before choosing an option, it’s helpful to understand the underlying cause. Our overview in erectile dysfunction basics explains common mechanisms and evaluation steps.

Options (comparison of approaches and formulations)

1. Standard on-demand tablets (25 mg, 50 mg, 100 mg)

When used: Most common approach for men with occasional or regular erectile dysfunction. Taken 30–60 minutes before sexual activity.

Pros:

• Well-studied, predictable onset (about 30–60 minutes)
• Flexible dosing (start low, adjust as needed)
• Effect duration: about 4–6 hours

Cons:

• Requires planning
• May be less effective after heavy meals (especially high-fat meals)
• Possible side effects: headache, flushing, nasal congestion, dyspepsia

Limitations/risks:

• Contraindicated with nitrates (risk of severe hypotension)
• Caution in severe cardiovascular disease
• Not effective without sexual stimulation

When to discuss with a doctor:

• If 50 mg is ineffective or causes side effects
• If you have heart disease, take alpha-blockers, or have low blood pressure

For dose adjustment strategies, see our guide on how to choose the right ED medication dose.

2. Low-dose approach (starting at 25 mg)

When used: For men over 65, those with liver/kidney impairment, or those sensitive to side effects.

Pros:

• Lower risk of adverse effects
• Safer starting point for medically complex patients

Cons:

• May be insufficient for moderate to severe ED

Limitations/risks:

• Still interacts with nitrates and certain antihypertensives
• Effect may be less robust

When to discuss with a doctor:

• If erection quality remains inadequate after several attempts
• If you are taking CYP3A4 inhibitors (e.g., some antifungals, antibiotics)

3. Higher-dose strategy (up to 100 mg)

When used: For patients who do not respond sufficiently to 50 mg and tolerate the medication well.

Pros:

• Higher efficacy in some cases
• May overcome moderate vascular ED

Cons:

• Increased likelihood of side effects
• Not suitable for all patients

Limitations/risks:

• Greater risk of headache, flushing, visual disturbances
• Should not exceed prescribed frequency (usually once per 24 hours)

When to discuss with a doctor:

• If you experience visual changes or prolonged erection (>4 hours)
• If you have borderline cardiovascular status

4. Alternative PDE5 inhibitors (comparison approach)

When used: If sildenafil is ineffective, poorly tolerated, or does not fit lifestyle preferences.

Examples: Tadalafil, vardenafil, avanafil.

Pros:

• Tadalafil: longer duration (up to 36 hours)
• Avanafil: potentially faster onset
• Different side-effect profiles

Cons:

• Cost differences
• Similar contraindications (nitrates)

Limitations/risks:

• Class-related adverse effects (hypotension, headache)
• Drug interactions similar across PDE5 inhibitors

When to discuss with a doctor:

• If timing flexibility is important
• If you prefer a longer “window of opportunity”

A broader comparison is available in PDE5 inhibitors comparison guide.

5. Combination approach (medication + lifestyle modification)

When used: For men with cardiovascular risk factors, obesity, diabetes, or smoking history.

Pros:

• Addresses root causes (vascular health)
• Improves long-term erectile function
• Enhances response to medication

Cons:

• Requires sustained effort
• Benefits may take weeks to months

Limitations/risks:

• No immediate cure from lifestyle changes alone in severe ED

When to discuss with a doctor:

• If ED may be an early marker of cardiovascular disease
• If you have metabolic syndrome or poorly controlled diabetes

Large comparison table

Approach	For whom	Effect / expectations	Risks	Notes
Standard 50 mg on demand	Most men with mild–moderate ED	Improved erection in 30–60 min; lasts 4–6 h	Headache, flushing, GI upset	Avoid heavy meals before dose
Low dose 25 mg	Older adults; liver/kidney issues	Milder effect; fewer side effects	May be insufficient	Good starting dose in complex cases
High dose 100 mg	Non-responders to 50 mg	Stronger erectile response	Higher adverse effect risk	Max once daily
Switch to tadalafil	Men wanting longer duration	Up to 36-hour window	Similar class risks	May be taken daily (low dose)
Lifestyle + medication	Cardiometabolic ED	Improved long-term outcomes	Slow onset of benefit	Exercise, weight loss, smoking cessation

For related treatment pathways, see ED treatment options overview.

Common mistakes and misconceptions when choosing

• “If it doesn’t work once, it never will.” Response may improve after several attempts under optimal conditions.
• Taking it after a heavy meal. High-fat meals can delay absorption.
• Ignoring psychological factors. Anxiety can reduce effectiveness.
• Using without medical evaluation. ED may signal cardiovascular disease.
• Mixing with nitrates or recreational drugs. This can cause dangerous hypotension.

Mini-guide to preparing for a consultation

Before seeing a healthcare provider, prepare:

• Medication list: including nitrates, antihypertensives, antidepressants
• Medical history: heart disease, diabetes, surgery, hormonal disorders
• Symptom record:
  • Onset (sudden or gradual)
  • Consistency (always or sometimes)
  • Morning erections present or absent
• Lifestyle factors: smoking, alcohol, exercise level
• Questions to ask:
  • What dose should I start with?
  • What side effects should prompt urgent care?
  • Are lab tests needed (testosterone, glucose, lipids)?

FAQ

1. How long does sildenafil last?

Typically 4–6 hours, though this varies by individual metabolism and dose.

2. Can I take it every day?

Usually no more than once per 24 hours unless specifically advised. If daily treatment is preferred, ask about alternative regimens in our daily vs on-demand ED therapy guide.

3. Does it increase sexual desire?

No. It improves blood flow but does not increase libido. Sexual stimulation is still required.

4. Is it safe with high blood pressure?

Often yes, but caution is required—especially with certain antihypertensives. Always review medications with a doctor.

5. What if it doesn’t work?

Ensure correct timing, adequate stimulation, and multiple attempts. If still ineffective, dose adjustment or alternative PDE5 inhibitors may help.

6. Can younger men use it?

Yes, if clinically indicated. However, psychological factors are more common in younger patients and should be assessed.

7. Are there serious side effects?

Rare but serious effects include priapism (erection >4 hours), sudden vision or hearing loss. Seek urgent care if these occur.

8. Is ED always a sexual problem?

No. It may be an early sign of vascular disease. A cardiovascular risk assessment is often recommended.

Sources

• U.S. Food and Drug Administration (FDA). Viagra (sildenafil) prescribing information.
• European Medicines Agency (EMA). Sildenafil-containing medicinal products.
• American Urological Association (AUA). Erectile Dysfunction Guideline.
• National Institute for Health and Care Excellence (NICE). Erectile dysfunction: management.
• Mayo Clinic. Erectile dysfunction – diagnosis and treatment.