Sildenafil

Sildenafil is an FDA-approved, clinically proven treatment for erectile dysfunction (ED) and pulmonary arterial hypertension (PAH). Available in strengths of 20 mg, 50 mg, 100 mg, 150 mg, and 200 mg, it delivers reliable, on-demand results backed by decades of research. Every order from Staminite ships discreetly to your door. Browse our full range below.

What Is Sildenafil?

Sildenafil citrate is a PDE5 inhibitor — a drug that blocks the phosphodiesterase type 5 enzyme in the body. During sexual arousal, the body releases nitric oxide, which produces cGMP (cyclic guanosine monophosphate). cGMP relaxes blood vessel walls in the penis, allowing increased blood flow and a firm erection. Sildenafil prevents cGMP from breaking down too quickly, prolonging and strengthening this natural response.

It was first approved by the FDA in 1998 under the brand name Viagra for ED. A separate approval followed for pulmonary arterial hypertension under the brand name Revatio. Today, the generic version — sildenafil citrate — is widely available and equally effective.

Uses of Sildenafil

1. Erectile Dysfunction (ED)

The primary and most well-known use. Sildenafil helps men achieve and maintain an erection sufficient for sexual activity. It does not cause an erection on its own — sexual stimulation is still required.

2. Pulmonary Arterial Hypertension (PAH)

Sold as Revatio, sildenafil 20 mg is used to relax blood vessels in the lungs, reducing the strain on the heart. It improves exercise capacity in PAH patients.

3. Off-Label Uses

Doctors may also prescribe it for:

• Performance anxiety-related ED — restores physical function when psychological factors contribute to ED
• Raynaud’s phenomenon — improves blood circulation in extremities
• High-altitude pulmonary edema (HAPE) — used off-label by climbers and mountaineers

Recommended Dosage Guide

For Erectile Dysfunction:

Strength	Recommended For	When to Take	Max Per Day
25 mg	Elderly, liver/kidney issues, first-timers	30–60 min before activity	Once
50 mg	Standard starting dose for most men	30–60 min before activity	Once
100 mg	When 50 mg is insufficient	30–60 min before activity	Once
150 mg / 200 mg	Higher-strength generics (use under guidance)	30–60 min before activity	Once

For Pulmonary Arterial Hypertension (PAH):

• 20 mg taken 3 times daily, approximately 4–6 hours apart
• Available as tablets, oral suspension (10 mg/mL), or injectable form

Important Dosage Notes

• Take on an empty stomach or after a light meal — heavy/fatty meals delay absorption
• Do not exceed one dose in 24 hours
• Elderly patients (65+) and those with liver or severe kidney problems should start at 25 mg
• Effects typically begin in 30–60 minutes and last 4–6 hours

Side Effects of Sildenafil

Common Side Effects

These affect a notable portion of users and are generally mild and temporary:

• Headache
• Facial flushing (warmth or redness)
• Nasal congestion or runny nose
• Indigestion or upset stomach
• Dizziness
• Blue-tinted or blurred vision (cyanopsia) — caused by mild PDE6 inhibition in the retina

Serious Side Effects (Seek Medical Help Immediately)

• Sudden vision loss in one or both eyes (may indicate NAION — Non-Arteritic Anterior Ischaemic Optic Neuropathy)
• Sudden hearing loss or ringing in the ears (tinnitus)
• Chest pain or irregular heartbeat
• Severe drop in blood pressure — especially if combined with nitrates
• Priapism — an erection lasting more than 4 hours (medical emergency; can cause permanent damage if untreated)

Rare but Reported

• Skin rash or allergic reaction
• Urinary tract infection
• Fainting (syncope)

Drug Interactions

Sildenafil interacts with several drug classes. Always inform your doctor about all medications before use.

Drug / Drug Class	Interaction	Risk Level
Nitrates (nitroglycerin, isosorbide)	Combined vasodilation causes severe BP drop	CONTRAINDICATED
Alpha-blockers (tamsulosin, doxazosin)	Additive blood pressure lowering, risk of fainting	Caution / Adjust Dose
CYP3A4 inhibitors (ketoconazole, ritonavir, erythromycin)	Increase sildenafil blood levels significantly	Reduce sildenafil dose
Other ED medications (tadalafil, vardenafil)	Additive hypotension, overlapping side effects	Do Not Combine
sGC stimulators (riociguat)	Dangerous hypotension	CONTRAINDICATED
Grapefruit / Grapefruit juice	Inhibits CYP3A4 enzyme, raises drug levels unpredictably	Avoid
Alcohol	Can worsen dizziness and blood pressure drop	Limit or Avoid
HIV protease inhibitors (saquinavir)	Increases sildenafil exposure up to 3-fold	Reduce to 25 mg max
Blood pressure medications	Additive hypotensive effects	Caution

Advantages

• Proven & FDA-Approved
• Fast-Acting (30–60 min)
• Affordable (generic)
• Dual Approval (ED + PAH)
• Well-Tolerated
• High Success Rate (70–85%)
• Accessible via telehealth

Disadvantages

• Not Spontaneous (planning required)
• Food-Dependent
• Short Duration (4–6 hrs)
• Cardiovascular Contraindications
• Side Effects at Higher Doses
• Prescription Required
• No Effect Without Arousal

How to Use It Safely

Timing: Take 30–60 minutes before sexual activity. Avoid heavy meals beforehand.

Grapefruit: Avoid completely — it raises drug levels unpredictably via CYP3A4 inhibition.

Alcohol: Limit consumption — alcohol amplifies blood pressure drop and dizziness.

Heart conditions: Do not use if you take any nitrate medication. Consult a doctor if you have a cardiac history.

Switching to tadalafil: Wait at least 24 hours after your last sildenafil dose before taking tadalafil.

Expiration: Tablets are stable for approximately 2 years from manufacture. Do not use expired pills — potency degrades.

Storage: Keep at room temperature (20–25°C), away from moisture and direct sunlight.

Who Should Not Take It?

• Men currently using nitrate medications (any form)
• Men who have had a heart attack or stroke in the past 6 months
• Those with severely low blood pressure (hypotension) or uncontrolled high blood pressure
• Men with severe liver impairment
• Those with a history of NAION (vision-threatening optic condition)
• Men with conditions that predispose to priapism (sickle cell disease, multiple myeloma, leukaemia)
• Anyone allergic to sildenafil citrate or any excipients in the tablet

Frequently Asked Questions

Q: How quickly does sildenafil work?

It typically takes effect within 30–60 minutes. On an empty stomach, some men notice effects as early as 20 minutes.

Q: Can I take sildenafil daily?

It is approved for on-demand use (not daily) for ED. Daily use is only for PAH patients under the 20 mg Revatio dosing protocol.

Q: What is the difference between 50 mg and 100 mg?

50 mg is the standard starting dose. 100 mg is for men who find 50 mg insufficient. Higher dose = higher efficacy but also higher side effect risk. Never self-escalate without medical guidance.

Q: Does it work if I’m not aroused?

No. Sildenafil only enhances the physiological response to sexual stimulation. It does not create desire or erections independently.

Q: Can I drink alcohol while taking it?

Moderate alcohol is unlikely to cause problems, but heavy drinking increases the risk of low blood pressure, dizziness, and reduced effectiveness. Best avoided.

Medical Disclaimer: The information on this page is for educational purposes only and does not constitute medical advice. Sildenafil is a prescription medication in the United States. Always consult a licensed healthcare provider before starting, stopping, or changing any medication. Staminite does not provide medical diagnoses or prescriptions.

References

1. MedlinePlus Sildenafil Monograph | National Library of Medicine / NIH
2. Mayo Clinic — Sildenafil Dosage and Safety Guide | Mayo Clinic
3. PubMed — Sildenafil: Two Decades of Benefits or Risks? | NCBI / National Library of Medicine
4. StatPearls — Sildenafil | NCBI Bookshelf