ED Pills Compared: Sildenafil, Tadalafil, Vardenafil and Avanafil

Below: one table from the four labels, the price per dose today, and how to think about which pill fits. We give no doses. Your prescriber picks the drug and the strength.

Types of ED pills: one class, four drugs

All four pills are PDE5 inhibitors. PDE5 is an enzyme that ends an erection. Blocking it lets more blood stay in the penis when you are aroused. None of them causes an erection on its own. The Viagra label says it works "only when he is sexually excited" (DailyMed: Viagra label, read 14 November 2026).

Because they share one action, they share one big warning. None may be taken with nitrates, the chest pain drugs such as nitroglycerin. The mix can drop blood pressure to a dangerous level. Our ED pill side effects guide quotes those warnings in full.

Viagra vs Cialis vs Levitra vs Stendra: the label table

Sources, all read 14 November 2026: the Viagra label, the Cialis label, the vardenafil label and the Stendra label on DailyMed.

What the labels actually say

Each label sets its own timing. Viagra "may be taken anywhere from 30 minutes to 4 hours before sexual activity" (Viagra label). Stendra "should be taken orally as needed as early as approximately 15 minutes before sexual activity" (Stendra label). That makes avanafil the fastest on paper.

Tadalafil is the long-lasting one. Its label says it "Improves erectile function compared to placebo up to 36 hours post dose" (Cialis label). A placebo is a dummy pill. Tadalafil is also the only one approved for daily use, and for an enlarged prostate.

Food matters for one of the four. The Viagra label says "When VIAGRA is taken with a high fat meal, the rate of absorption is reduced" (Viagra label). In plain words, a heavy meal can slow sildenafil. The other three labels say food makes no real difference. Cialis "may be taken without regard to food", and Stendra "may be taken with or without food".

Side effects overlap a lot. The Stendra label lists "headache, flushing, nasal congestion, nasopharyngitis, and back pain" as most common (Stendra label). Nasopharyngitis means a sore nose and throat, like a cold. Back pain and muscle aches stand out on the tadalafil label. Brief vision changes stand out on the sildenafil label.

Price per dose today

The labels decide what each pill does. The market decides what it costs. Here is the cheapest dose we can read for each, with the online visit included where a program sells it.

Prices checked November 14, 2026. Generic sildenafil and tadalafil cost a few dollars or less a dose. Vardenafil and avanafil cost far more, because few companies make them. Our vardenafil cost guide and Stendra cost guide give every price we found for those two.

Many programs sell both cheap generics. These are three of them, read on their own pages:

Which ED pill is best?

No label claims to beat the others. Each drug was tested against a dummy pill, not in a head-to-head race. So "best" depends on what matters to you.

• Lowest price: generic sildenafil or generic tadalafil. Both cost a few dollars or less per dose online.
• Longest window: tadalafil, with up to 36 hours on its label. It also has a daily form; our daily tadalafil cost guide prices it.
• Fastest on the label: avanafil, from about 15 minutes. It is also the hardest to find and the most expensive.
• Big meal near the time: tadalafil, vardenafil and avanafil labels say food does not matter much. Sildenafil can be slowed by a high fat meal.
• Enlarged prostate too: tadalafil is the only one approved for that as well.

For the two most common pills in depth, see sildenafil vs tadalafil. For vardenafil against sildenafil, see vardenafil vs sildenafil.

Viagra alternative drugs

The three other FDA-approved pills are the real Viagra alternatives. Tadalafil is the one most programs offer. Vardenafil and avanafil exist but are sold by few programs.

Many sellers also offer compounded chews, mints and multi-drug tablets. These are not FDA-approved, and a pharmacy mixes each one to order. Our guide to compounded ED medication explains what that means for you.

Supplements sold as natural Viagra are a different matter. The FDA warns that male enhancement and stamina pills "are likely to be contaminated with dangerous hidden ingredients" (FDA: tainted sexual enhancement products, read 14 November 2026). Those hidden ingredients are often the same ED drugs, at unknown strengths. Only a licensed program with a prescription gives you a known drug at a known strength.

How we rank programs

Payment never moves a rank. Ro is our top-scored ED program today, on price, openness, care, access and reputation. See every score on our best ED programs page.