Which ED Medication Is Best? Viagra vs Cialis vs Levitra – Doctor-Reviewed Comparison

“I don’t feel as confident as I used to.”
“I’ve started feeling anxious about my intimate life.”
Do these concerns sound familiar?

Erectile dysfunction (ED) is experienced by approximately 1 in 3 adult Japanese men,
making it a surprisingly common condition.
It is also increasing among men in their 20s and 30s,
and in today’s stress-heavy society it can happen to anyone.

The good news: when treated properly,
ED medications are effective for roughly 80% of patients,
making ED one of the most treatable conditions in men’s health.
In this article, reviewed by a board-certified urologist,
we will thoroughly explain the different types of ED medications,
how to choose one, possible side effects,
and how an online consultation leads to a prescription.

What is erectile dysfunction (ED)?
The basics to know first

Erectile dysfunction (ED) refers to
the inability to achieve or maintain an erection sufficient for sexual intercourse.
It is not limited to a complete inability to get an erection.

The following symptoms are also considered forms of ED:

According to the Japanese Society for Sexual Medicine,
an estimated 11.3 million or more adult Japanese men are affected by ED.
It is not limited to men over 40 —
psychogenic ED is also on the rise among men in their 20s and 30s,
making it a condition that can affect anyone in today’s stressful society.

A simple look at the mechanism of erection

A normal erection occurs through the following process:

ED occurs when a breakdown arises somewhere in this process.
ED medications work by inhibiting PDE5, the enzyme that breaks down cGMP in STEP 3,
which improves blood flow and supports erection.

The 4 causes of ED —
which one applies to you?

The causes of ED are broadly classified into four types.
Check which one best matches your situation.

1. Psychogenic ED (functional ED)

This type of ED is caused by psychological factors such as
stress, anxiety, and pressure.
It is the most common type in men in their 20s and 30s,
often triggered by work stress, relationship issues with a partner,
or previous negative sexual experiences.

2. Organic ED

Organic ED is caused by
physical factors such as blood vessels, nerves, or hormones.
It is common in men over 40,
with major risk factors including atherosclerosis from aging and
lifestyle-related diseases such as diabetes, hypertension, and dyslipidemia.

3. Mixed ED

Mixed ED develops when
both psychological and physical factors are intertwined.
In reality, mixed ED is the most common type.
For example, an age-related decrease in erectile function leads to anxiety,
which then worsens the ED further — a negative cycle.

4. Drug-induced ED

This type of ED is caused as a
side effect of medications you are currently taking.
Certain drugs — antihypertensives, antidepressants,
medications for benign prostatic hyperplasia,
and AGA (androgenetic alopecia) treatments such as finasteride — can cause ED.

ED by age group:
men in their 20s, 30s, 40s, and 50s

Do you think of ED as something that only affects middle-aged or older men?
In fact, ED can occur at any age.
Let’s look at the characteristic causes for each age group.

ED in your 20s — more than 1 in 4 have experienced it

It may come as a surprise, but data show that
about 26.6% of men in their 20s have experienced some form of ED.
Anxiety about a first sexual experience, pressure to perform for a partner,
and reduced response to a real partner due to excessive porn use
are mostly psychogenic factors.

ED in younger men tends to
respond well to medications and has a high improvement rate.
Rather than telling yourself, “I’m too young to have ED”,
speaking with a doctor early is the fastest route to resolution.

ED in your 30s — caught between work and family

In your 30s, career responsibilities grow
and major life events such as marriage and raising children often pile up.
Many men experience
“timing ED”, a form of psychogenic ED
triggered by the pressure of trying to conceive.
Lack of sleep and irregular lifestyle habits are also common at this age.

ED in your 40s to 50s — physical changes add up

From your 40s onward, in addition to psychological factors,
physical factors such as
hypertension, diabetes, and dyslipidemia as well as
a decline in testosterone (the male hormone)
intertwine and “mixed ED” becomes more common.
This is exactly the age at which medical support matters most.

In-depth comparison of the 3 ED medications:
Viagra, Cialis, and Levitra

In Japan, there are currently three main ED medications that can be prescribed.
All three are in the category known as PDE5 inhibitors,
and although they share the same mechanism of action,
they differ in duration of effect, speed of onset, and how food affects them.

Characteristics of Viagra (sildenafil)

Released in the United States in 1998, it is
the world’s first ED medication.
With more than 20 years of clinical experience,
it has by far the largest body of data of any ED drug.
The effect tends to be relatively clear and distinct,
giving many users a strong sense that “the medicine is working”.

On the other hand, it
is strongly affected by food,
so it is ideally taken on an empty stomach.
Care is needed when using it after a meal on a date.

Characteristics of Cialis (tadalafil)

Its greatest strength is a long duration of up to 36 hours.
It holds the #1 global market share among ED medications,
and because a dose taken Friday night can last into Sunday morning,
it is nicknamed the “weekend pill” overseas.

It is also minimally affected by food,
making it a popular choice for men who want
to engage in intimacy at a natural timing.
Because the effect is mild and you are unlikely to feel that you have taken a drug,
it is often chosen by first-time ED-medication users.

Characteristics of Levitra (vardenafil)

Of the three medications, it has the fastest onset.
The effect appears in just 15-30 minutes after dosing,
making it well suited to sudden situations.
This is because its active ingredient dissolves easily in water
and is absorbed rapidly.

How to choose the right ED medication for you

For those still wondering, “Which one should I actually pick?”, here are
recommendations by use case.

Side effects of ED medications and
precautions when taking them

ED medications have more than 20 years of clinical experience,
and when used under a doctor’s prescription, they are considered safe.
Still, there are some side effects and precautions to be aware of.

Common side effects (mild and temporary)

These side effects generally subside on their own as the drug wears off.
If you are worried about side effects, you can also start with a low dose and monitor the response.

Contraindications (medications that must never be combined)

Drug-specific side effects

Each of the three medications has characteristic side-effect tendencies.

For those who want a medication with fewer side effects,
Cialis (tadalafil) tends to have a milder side-effect profile and is a good choice.

The dangers of personal imports and online shops

Self-check:
5 signs that may indicate ED

For those who wonder, “Could I have ED?”, we have prepared a
simple self-check based on
the International Index of Erectile Function short form (IIEF-5 / SHIM).

A quick check using the EHS (Erection Hardness Score)

Another simple tool is the
Erection Hardness Score (EHS),
which rates the hardness of an erection on a simple 0-4 scale.

Getting ED medication through
an online consultation

“It feels embarrassing to go to a clinic for ED treatment…”
For anyone who feels this way, online medical consultations are a popular option.
You can see a doctor from home with just a smartphone,
and the medication is delivered in privacy-friendly packaging.

Cost of ED treatment —
generics start at just a few hundred yen per tablet

In principle, ED treatment is private-pay (not covered by public insurance).
However, since April 2022, insurance coverage has been granted for fertility-treatment purposes only.
For general ED treatment, the typical cost is as follows.

In addition, initial and follow-up consultation fees or shipping fees may apply.
At our clinic, for online consultations,
the initial consultation fee is free.

Lifestyle changes that
prevent and improve ED

Rather than relying solely on ED medications,
reviewing your daily lifestyle habits can help prevent and improve ED.
This is especially important for those with organic or mixed ED,
where addressing the root cause is essential.

1. Moderate aerobic exercise

At least 150 minutes of aerobic exercise per week (walking, jogging, swimming, etc.) is recommended.
Exercise is effective for
improving vascular endothelial function and
maintaining testosterone levels.
Research from Harvard University has reported that regular exercise
reduces the risk of ED by about 30%.

2. Reviewing your diet

A Mediterranean-style diet (centered on vegetables, fruits, fish, and olive oil)
is considered effective for preventing ED.
In particular, zinc (oysters, beef, and nuts) and
citrulline (watermelon, cucumber) are
nutrients known to help support male sexual function.

3. Quitting smoking and moderating alcohol

Smoking constricts blood vessels and promotes atherosclerosis,
making it a major risk factor for ED.
In some cases, vascular function improves within a few months of quitting.
Excessive alcohol also worsens ED.
Keep alcohol intake moderate (around one medium bottle of beer a day).

4. Quality sleep and stress management

Testosterone is secreted mainly during sleep.
Chronic sleep deprivation lowers testosterone
and raises the risk of ED.
Aim for 7-8 hours of quality sleep, and
build in stress reduction practices (hobbies, meditation, bathing, etc.).

Frequently asked questions (FAQ)

Here are the questions we most often receive from patients about ED treatment.

Summary: ED is a treatable condition —
take the first step

Let us recap the key points of this article.

ED is not something to be embarrassed about —
it is a medically treatable condition.
You do not have to suffer on your own.
With the right medication and lifestyle improvements,
it is entirely possible to regain your confidence.

Why not start by consulting a doctor?

Medical supervision: Men’s Care Clinic physicians
This article has been created under the supervision of board-certified urologists, based on the latest medical evidence.

* This article is intended to provide medical information and does not constitute diagnosis or treatment.
* For details about symptoms or treatment, always consult a physician.
* The information was current as of March 2026.