ED Pills Compared: Which Works Fastest, Lasts Longest and Costs Least

There are four FDA-approved ED pills, and they all work the same way: they block the PDE5 enzyme so blood flow increases when you're aroused. The differences are practical. Tadalafil lasts the longest (up to 36 hours), avanafil works fastest (about 15 minutes), and generic sildenafil and tadalafil are the cheapest, with telehealth plans starting in the low teens per month.

The four ED pills side by side

	Sildenafil (Viagra)	Tadalafil (Cialis)	Vardenafil (Levitra)	Avanafil (Stendra)
Usual starting dose	50 mg	10 mg (or 2.5–5 mg daily)	10 mg	100 mg
Dose range	25–100 mg	5–20 mg	5–20 mg	50–200 mg
Take before sex	About 1 hour (30 min–4 hours)	Any time up to 36 hours	About 1 hour	About 15 minutes (100–200 mg)
Half-life	About 4 hours	17.5 hours	4–5 hours	About 5 hours
Daily-use option	No	Yes	No	No
High-fat meal	Delays and weakens it	No effect	Weakens it	Delays and weakens it
Generic in the US	Yes	Yes	Yes	Generic label exists; availability limited

All four are taken no more than once a day.

Side effects

The most common side effects are shared across the class, and they rise with dose:

Side effect	Sildenafil 50 mg	Tadalafil 10 mg	Vardenafil	Avanafil 100 mg
Headache	21%	11%	15%	6.9%
Flushing	19%	3%	11%	4.3%
Indigestion	9%	8%	4%	—
Nasal congestion	4%	3%	9% (rhinitis)	2.9%
Back or muscle pain	3–4%	5% back pain	2%	2%

Sildenafil is the one most likely to cause a temporary blue-green tinge to vision, especially at 100 mg (11% in trials). Tadalafil is the one most associated with back and muscle aches.

Who should not take them

• Anyone using nitrates (nitroglycerin, isosorbide) or riociguat: the combination can drop blood pressure dangerously. With tadalafil, at least 48 hours must pass before a nitrate can be given.
• Alpha-blockers (for prostate or blood pressure) require a lower starting dose.
• Strong CYP3A4 inhibitors such as ritonavir, ketoconazole or clarithromycin sharply raise levels; doses are capped (for example, sildenafil at 25 mg per 48 hours with ritonavir). Avanafil shouldn't be used with them at all.

"Long-lasting in bed": ED or premature ejaculation?

People searching for a pill to last longer usually mean one of two different problems:

1. Keeping an erection. That's ED, and tadalafil gives the longest window.
2. Finishing too quickly. That's premature ejaculation, and ED pills aren't the main treatment. Clinicians may prescribe an SSRI such as sertraline or paroxetine off-label, or a numbing spray or cream applied before sex.

Some men have both. An online clinician can sort out which treatment fits.

Skip the gas station pills

The FDA has repeatedly found sexual enhancement products sold as "natural" in gas stations and online that contain hidden prescription drugs, sometimes at unpredictable doses. They're especially dangerous for men on nitrates. Real generic sildenafil or tadalafil through a telehealth service usually costs less and contains exactly what the label says.

What generic ED pills cost through telehealth

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