Sildenafil vs Tadalafil: Cost per Dose and Label Differences

Below: what each FDA label says, which one is safer, and what a dose costs at each program we track. We give no doses. Your prescriber picks the drug and the strength.

Viagra vs Cialis: the short version

Both drugs block an enzyme called PDE5. That lets more blood flow into the penis when you are aroused. Neither one causes an erection on its own. The Viagra label says it "helps a man with erectile dysfunction get and keep an erection only when he is sexually excited" (DailyMed: Viagra label, read 14 November 2026).

The main differences sit in three places: how long the effect lasts, whether food slows it, and whether it is approved for daily use.

Sources: the Viagra label and the Cialis label on DailyMed, read 14 November 2026. Our ED pills compared guide adds vardenafil and avanafil.

How long each one lasts

The Viagra patient guide says to "Take VIAGRA about 1 hour before sexual activity." (Viagra label) That makes it a plan-ahead pill. Our guide to how long Viagra lasts has the timing.

Tadalafil lasts longer. In the Cialis trials, men compared it with a dummy pill (a placebo). The label says "CIALIS for use as needed was shown to improve erectile function compared to placebo up to 36 hours following dosing." (Cialis label) That long window is why some men call it the weekend pill. See how long Cialis lasts for more.

Longer is not always better. A drug that stays in the body longer also keeps any side effect around longer. Talk this through with your prescriber.

Does food matter?

For sildenafil, yes. The 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 it down.

For tadalafil, no. Its label says "The rate and extent of absorption of tadalafil are not influenced by food" (Cialis label). Grapefruit is a different story; see Cialis and grapefruit.

Daily use and the prostate

Tadalafil is the only one of the two approved for daily use. The label also lists a second use: "CIALIS is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH)." (Cialis label) BPH means an enlarged prostate, which can make you pass urine often or weakly. Men with both problems sometimes ask about tadalafil for that reason. Our daily tadalafil cost guide prices the daily plans.

Tadalafil vs sildenafil: which is safer?

Neither label calls one safer. Both carry the same main warning. The Viagra guide says "Do not take VIAGRA if you take any other medicines called" nitrates (Viagra label). The Cialis guide says "Do not take CIALIS if you take any medicines called" nitrates (Cialis label). Nitrates are heart drugs such as nitroglycerin. Taken together with either pill, they can cause a big drop in blood pressure.

The side effects overlap too. Headache and flushing show up on both labels. Our ED pill headache guide has the rates. Back pain and muscle aches are listed more for tadalafil. Our Viagra vs Cialis side effects guide puts the label tables side by side.

Which one is safer for you depends on your heart, your other medicines and your history. That is a question for the clinician who reviews your answers.

Cost per dose: sildenafil vs tadalafil

Both are cheap as generics. These are the per-dose prices each program publishes, read on its own page.

The lowest figures often need a set pack, a longer supply or the lowest strength. Each program's full plan list, with read dates, is on our sildenafil price page and tadalafil price page.

With your own prescription, a cash pharmacy is cheaper still. Cost Plus Drugs listed 30 tablets of generic sildenafil at $6.69 and 30 tablets of generic tadalafil at $6.69, before shipping (Cost Plus Drugs).

Brand Viagra vs brand Cialis

The brand names cost far more than the generics. Brand Viagra at Ro is $90 a dose. Brand Cialis at Rex MD starts at $29 a dose. The generic holds the same active ingredient. The FDA says "Generic drugs are FDA-approved copies of brand drugs." (FDA: generic drugs questions and answers, read 14 November 2026) Our guide to generic Viagra vs Viagra explains what changes and what does not.

Chews and mints are a third choice

Many programs also sell chews, mints and dissolving tablets with sildenafil or tadalafil in them. These are compounded, which means a pharmacy mixes them to order. They are not FDA-approved. Our guide to compounded ED medication explains the difference. PT-141 is a shot that works on the brain instead; see PT-141 vs Viagra.