Cialis 20 mg: What You Need to Know Before Starting It

March 29, 2024

You might have seen Cialis® — the erectile dysfunction (ED) drug — available in doses ranging from 2.5 mg to 20 mg. Surely, more is better right?

Well, not always. Cialis 20 mg is an effective erectile dysfunction treatment, but so are the lower doses.

Below, we’ve covered what Cialis 20 mg is used for, the benefits and side effects of this dose of Cialis and how it stands up against other strengths.

(Related: The Best ED Pills for Men)

What is Cialis 20 mg Used for?

Cialis is the brand name for tadalafil. Tadalafil is a phosphodiesterase type 5 inhibitor or, if you want less of a mouthful, a PDE5 inhibitor.

Cialis is FDA-approved to treat:

Erectile dysfunction
Benign prostatic hyperplasia (BPH), or an enlarged prostate

Cialis dosages include 2.5 mg, 5 mg, 10 mg and 20 mg.

You can take Cialis on an as-needed basis and pop a pill before sex, or you can take a daily dose of Cialis, so you’re always ready for action.

If you’re taking it as needed, you’re likely going to be prescribed 5mg, 10mg or 20mg. 10mg is the typical starting dose, and it can be adjusted up or down depending on efficacy and side effects.

But you won’t be taking 20 mg Cialis daily. Daily doses of Cialis are the lower doses of 2.5 mg and 5 mg.

How does Cialis work? For ED — which is when you struggle to get or keep an erection — Cialis works by dilating the blood vessels in the penis, which leads to a firmer erection.

Cialis — 20 mg or otherwise — doesn’t just give you an erection though. Some form of sexual stimulation is required to get hard.

Cialis 20 mg may be a more effective treatment of ED than the 10 mg version. Clinical trials found that 68 percent to 77 percent of men taking 10 mg Cialis were able to have penetrative sex with their partner. Of those taking 20 mg Cialis, 76 percent to 85 percent were able to have penetrative sex.

But not all research agrees — a smaller daily dose may be just as effective as the as-needed Cialis treatment.

A systematic review and meta-analysis looked at six randomized controlled trials with a total of over 1,500 patients and compared an as-needed tadalafil treatment to a once-a-day dose. The results showed that both treatments had about the same effectiveness.

Tadalafil can also be used to treat pulmonary arterial hypertension, a form of high blood pressure that affects the blood vessels in the lungs.

A 20 mg dose may come in handy here. A 2006 study found that a single dose of 20 mg of tadalafil lowered average blood pressure over 26 hours in patients with uncontrolled high blood pressure.

You can learn more in our guide to tadalafil uses.

(Related: How Much Does Viagra Cost?)

The Benefits of Cialis

Cialis benefits include:

Cialis lasts a long time. While Cialis is just as effective as Viagra, 20mg Cialis lasts longer in your body and is known as the “weekend pill” for a reason. Because you can pop one pill and have sex whenever you like over the next 36 hours (give or take a few hours), it offers more spontaneity.
In comparison, avanafil only lasts up to six hours and Viagra® only lasts up to four hours.
Cialis is effective. Clinical trials show that Cialis can be effective for all severities and types of ED, including difficult-to-treat ED. If you find Cialis 10 mg isn’t working for you, a Cialis 20 mg tablet might do the trick.
You don’t need to take it every day. Depending on your preference and lifestyle, you may not want to take Cialis day in and day out. In fact, the 20mg dose should only be taken as needed.
Side effects are typically mild. Side effects of Cialis are usually mild and should go away on their own — although they may be worse with higher doses. For example, research shows that 11 percent of people taking tadalafil 10 mg got a headache, whereas 15 percent of those taking tadalafil 20 mg got a headache.
Some side effects have the same likelihood in both doses, such as flushing and limb pain. If the side effects of Cialis 20 mg are too much, a healthcare provider may reduce your dose.
Less flushing. If this is a particularly annoying side effect of ED drugs for you, switching to Cialis may be the answer. A 2017 systematic review and meta-analysis compared sildenafil (the generic of Viagra) and tadalafil. It found that tadalafil caused lower rates of flushing.
Muscle aches and back pain were more common in tadalafil than sildenafil, though. You can’t win ‘em all. Overall, tadalafil and sildenafil had similar efficacy and safety, but men and their partners tended to prefer tadalafil. You can learn more about the two ED treatments in our Cialis vs. Viagra guide.