ED pills, compared honestly
The four FDA-approved erectile-dysfunction pills, side by side — how fast each works, how long it lasts, whether food matters, and our independent recall-safety rating. They are equally effective for most men; the real choice is about timing. We rate medications; we don’t sell them or prescribe them.
The rules that apply to all four
Never combine an ED pill with a nitrate (nitroglycerin and similar heart medicines) — together they can drop blood pressure dangerously. There is a second absolute rule people miss: never with a guanylate-cyclase stimulator — riociguat (Adempas) for pulmonary hypertension or vericiguat (Verquvo) for heart failure. Both are labeled contraindications on all four pills.
An erection lasting more than 4 hours is an emergency — go to an emergency room. Untreated priapism can permanently damage the penis, and every one of these labels carries that instruction. Stop the drug and get care for sudden vision loss in either eye(NAION) or sudden loss of hearing. Sildenafil’s temporary blue tinge is a different, harmless effect — do not let it blur the two.
On an alpha-blocker for blood pressure or the prostate, start at the lowest dose and only once the alpha-blocker dose is stable — the combination can drop blood pressure and cause fainting; tadalafil is specifically not recommended with an alpha-blocker when used for the prostate. If your heart condition already makes sexual activity inadvisable, these drugs are not recommended at all — a labeled warning separate from the nitrate rule. And because new erectile dysfunction can be an early warning of heart or blood-vessel disease, it is a reason to see a doctor, not just to order a pill online.
Sildenafil (Viagra)
70/100- Starts in
- About 30-60 minutes
- Lasts
- About 4-6 hours
- With food
- A high-fat meal delays it — best taken on a relatively empty stomach.
The original and most-recognised. It can cause a temporary blue-ish tinge to vision at higher doses. The generic (sildenafil) is inexpensive and identical in active ingredient. Start at 25 mg if you are over 65 or have significant kidney or liver impairment, and the dose also needs lowering with strong CYP3A4 inhibitors such as ritonavir.
VIAGRA (sildenafil citrate) tablet — FDA label, DailyMed ↗- Starts in
- About 30-60 minutes
- Lasts
- Up to 36 hours — the longest, hence the 'weekend pill'
- With food
- Not affected by food — can be taken with or without a meal.
Its long window and food-independence make it the most flexible. It also comes as a low daily dose for men who want spontaneity, and Its restrictions are the broadest of the four, not the narrowest: with a creatinine clearance under 30 or on dialysis, the as-needed dose must not exceed 5 mg every 72 hours and daily dosing is not recommended; it is not recommended in severe liver impairment; and it is specifically NOT recommended alongside an alpha-blocker when used for the prostate. The same molecule is FDA-approved for an enlarged prostate (BPH).
CIALIS (tadalafil) tablet — FDA label, DailyMed ↗- Starts in
- About 30-60 minutes
- Lasts
- About 4-5 hours
- With food
- A high-fat meal can delay it — take on a lighter stomach.
Similar in profile to sildenafil. It should be used with extra caution in men with certain heart-rhythm (QT) issues, and the label bars it outright in severe liver impairment (Child-Pugh C) and in anyone on dialysis.
LEVITRA (vardenafil) tablet — FDA label, DailyMed ↗- Starts in
- About 15-30 minutes — the fastest
- Lasts
- About 4-6 hours
- With food
- Can be taken with or without food.
The newest of the four; its fast onset is its selling point. A generic avanafil is now available in the US. Do not use it in severe kidney or severe liver impairment.
STENDRA (avanafil) tablet — FDA label, DailyMed ↗See a clinician online
Licensed online providers — consult & get prescribed if eligible.
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Frequently asked questions
Which ED pill is the best?
There is no single best — they are all PDE5 inhibitors and all effective; the difference is timing. Tadalafil (Cialis) lasts up to 36 hours and is not affected by food, so it suits spontaneity. Avanafil (Stendra) starts fastest (~15-30 minutes). Sildenafil (Viagra) and vardenafil (Levitra) last a few hours and work best on an emptier stomach. The right one depends on your health, other medicines and what you want from it — a prescriber's decision.
What is the one safety rule for all ED pills?
There are two absolute rules, not one. Never take any of them with nitrate heart medicines (like nitroglycerin), and never with a guanylate-cyclase stimulator — riociguat (Adempas) or vericiguat (Verquvo). Either combination can cause a sudden, dangerous drop in blood pressure. Separately, an erection lasting more than 4 hours is an emergency: go to an emergency room, because untreated priapism can cause permanent damage. Tell your prescriber about every medicine you take, especially nitrates and alpha-blockers for blood pressure or the prostate. And because ED can be an early sign of heart or blood-vessel disease, new ED is a reason to see a doctor, not just to buy a pill.
Do ED pills work without arousal?
No. All four need sexual stimulation to work — they improve the blood-flow response to arousal, they do not create it on their own. They are also not approved for or effective in women.
Is generic sildenafil the same as Viagra?
Yes — generic sildenafil has the same active ingredient as Viagra and must meet the FDA's bioequivalence standard, usually at a fraction of the price. The same is true of generic tadalafil versus Cialis. Ask your pharmacist which your plan covers.
Sources: each drug’s FDA label (openFDA / DailyMed), linked on its card. General reference information, not medical advice, and not a recommendation to take any drug. ED is worth a conversation with a clinician — both to choose safely and because it can signal something treatable.