Tadalafil 2.5 mg vs 5 mg

May 20, 2025/Andrew Le

Both tadalafil 2.5 mg and 5 mg help improve erections, but they don’t work the same for everyone. 

Does the higher dose mean more effective? Or more side effects? 

In this article, you’ll learn how these two doses compare in terms of effectiveness, safety, and how they’re used.

🔑 Key Takeaways

➤ The 5 mg dose of tadalafil works better for more men and helps relieve urinary symptoms more than the 2.5 mg dose.

➤ Some men see help with erections on 2.5 mg, but it is less consistent for younger or older men, smokers, and those with higher body weight.

➤ Men taking 5 mg often notice stronger erection improvements by the second or third day of treatment.

➤ Both doses are generally safe, with most side effects being mild, like headache or back pain, and very few serious issues.

➤ The 5 mg dose has a slightly higher chance of mild side effects than 2.5 mg but still rarely causes people to stop treatment.

➤ You take either dose once a day at the same time, with or without food, and you do not have to plan it around sexual activity.

➤ If you miss a tablet, you simply take it as soon as you remember and do not take two doses at once.

Efficacy

Tadalafil 2.5 mg helps some men with erections but works less well for urinary symptoms and certain groups, while 5 mg works better and helps more people.

Tadalafil 2.5 mg Efficacy

According to a study, tadalafil 2.5 mg taken once daily for 12 weeks helped improve erections in men with erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). The International Index of Erectile Function (IIEF-EF) score went up significantly compared to placebo (which means it worked better than no treatment). But for urinary symptoms, the improvement was small. On average, the symptom score dropped by about 4.6 points, compared to a 3.8-point drop with placebo — and this difference was not considered statistically strong.

According to a study, the 2.5 mg dose worked, but it was weaker in some groups. For example, in men under age 50 and over age 65, the improvement was much less than with the higher dose. In men who were obese (body mass index of 30 or more), smokers, or men who had never used similar medications before, the 2.5 mg dose often failed to make a meaningful difference. For obese men, the chance of reaching meaningful improvement (called MCID, or minimal clinically important difference) was about the same as placebo, meaning it likely didn’t help much. Among smokers, the benefit was also very small.

Another study reported that with 2.5 mg, men began seeing more successful intercourse attempts by day 3 of treatment. Before that, there wasn’t much difference from placebo.

In men with diabetes, one study showed that tadalafil 2.5 mg still led to clear improvements in erection scores and sexual activity, with success rates much better than placebo.

Tadalafil 5 mg Efficacy

Tadalafil 5 mg once daily showed stronger and more consistent benefits. According to the same study above, erections improved significantly, and urinary symptoms improved as well. The average urinary symptom score dropped by about 6.1 points, which was clearly better than placebo.

The same study also showed that the 5 mg dose worked across almost all groups. For example, in men under 50, about 79% reached meaningful improvement, and among men aged 50–64, around 69% improved. In obese men, about 67% improved, and even among smokers, about 72% improved — all much better than placebo.

Also, another study reported that tadalafil 5 mg started working fast. By day 2, almost 49% of men were already having successful intercourse attempts, compared to about 37% on placebo. That’s nearly a 12% difference in just two days!

In diabetic men, the same study found that the 5 mg dose also worked well, boosting erection scores and improving sexual activity significantly compared to placebo.

Safety and Tolerability

Tadalafil 2.5 mg and 5 mg are generally safe, with mostly mild side effects like headache and back pain, and very few serious problems.

Tadalafil 2.5 mg Safety and Tolerability

Study showed that tadalafil 2.5 mg was well tolerated over 12 weeks of daily use. The number of men reporting side effects was low, and most of the side effects were mild. The most common ones were headache, back pain, and indigestion (dyspepsia). Serious side effects were rare and did not happen more often than with placebo. 

Importantly, there were no dangerous changes in blood pressure when standing (orthostatic vital signs) or in measures of how well the bladder empties (uroflowmetry and postvoid residual volume).

So, while you might get a mild headache or backache, the 2.5 mg dose overall has a good safety profile and causes very few serious problems.

Tadalafil 5 mg Safety and Tolerability

Tadalafil 5 mg also showed a good safety profile, but as expected with the higher dose, there were slightly more side effects compared to 2.5 mg. In the same study, the 5 mg group reported more headaches, back pain, and indigestion, but again, most cases were mild. Importantly, no serious safety problems were reported, and blood pressure and bladder function remained stable.

The same study also tested tadalafil 5 mg and found that although side effects were more common than with placebo, they were mild and didn’t lead to many people stopping the treatment.

Administration

Tadalafil 2.5 mg and 5 mg are taken once daily at the same time, with or without food, and are not timed around sex.

Tadalafil 2.5 mg Administration

Tadalafil 2.5 mg is used as a once-daily treatment for ED. According to the NHS, you should take one 2.5 mg tablet at about the same time every day, without worrying about when you plan to have sex. You should swallow the tablet whole with water or juice — but avoid grapefruit juice, as it can interact with the medicine.

The starting dose is usually 2.5 mg daily, and it may be increased to 5 mg if needed, depending on how well it works and how well you tolerate it. You can take it with or without food. If you forget a dose, just take it as soon as you remember, but never take two doses at once.

Importantly, this low-dose regimen is meant to provide continuous background improvement, so it does not require you to time the dose around sexual activity.

Tadalafil 5 mg Administration

The NHS recommends taking one 5 mg tablet once daily, ideally at the same time each day. Just like the 2.5 mg dose, swallow the tablet whole with water or juice (again, skip the grapefruit juice), and you can take it in the morning or evening.

5 mg is the usual maintenance dose for once-daily ED treatment and for BPH. If you’re also taking medications like finasteride for BPH, you should still take only 5 mg of tadalafil once daily, typically for up to 26 weeks. You don’t need to time the dose around sexual activity because the daily use is designed to provide steady improvement.

If you miss a dose, the advice is similar: take it as soon as you remember, but do not double up on doses.

Wrap Up

Choosing between tadalafil 2.5 mg and 5 mg depends on how well each works for your needs and how your body handles it. The 5 mg dose often brings stronger and faster results, especially for men with more severe symptoms or other health issues like obesity or diabetes. On the other hand, the 2.5 mg dose may suit those who only need mild help or want to start low to see how they react.

The daily dosing gives steady improvement without needing to plan around sex. 

So, which dose is right for you? That choice is best made with your doctor, who can help match the treatment to your body and lifestyle.

Frequently Asked Questions

What happens if I take too much?

You may get a headache, dizziness, or vision changes. Call NHS 111 or go to A&E right away.

Can I drink grapefruit juice with tadalafil?

No, avoid grapefruit juice. It can affect how the medicine works in your body.

How long does tadalafil last?

For ED, it can work up to 36 hours after you take it.

Do I need to be sexually excited for it to work?

Yes, sexual excitement is needed for the medicine to help with erections.

What if I have trouble swallowing the tablets?

Talk to your pharmacist. They can suggest tips or help you get an easier-to-open container.

Can anyone take tadalafil?

No, people with certain heart, kidney, or liver problems may need a lower dose or should avoid it. Ask your doctor.

Sources

  • Egerdie, R. B., Auerbach, S., Roehrborn, C. G., Costa, P., Sanchez Garza, M., Esler, A. L., Wong, D. G., & Secrest, R. J. (2012). Tadalafil 2.5 or 5 mg administered once daily for 12 weeks in men with both erectile dysfunction and signs and symptoms of benign prostatic hyperplasia: Results of a randomized, placebo-controlled, double-blind study. The Journal of Sexual Medicine, 9(1), 271–281. https://doi.org/10.1111/j.1743-6109.2011.02504.x
  • Brock, G., Ni, X., Oelke, M., Mulhall, J., Rosenberg, M., Seftel, A., D’Souza, D., & Barry, J. (2016). Efficacy of continuous dosing of tadalafil once daily vs tadalafil on demand in clinical subgroups of men with erectile dysfunction: A descriptive comparison using the integrated tadalafil databases. The Journal of Sexual Medicine, 13(5), 860–875. https://doi.org/10.1016/j.jsxm.2016.02.171
  • Seftel, A., Goldfischer, E., Kim, E. D., Dula, E., Zeigler, H., & Burns, P. (2011). Onset of efficacy of tadalafil once daily in men with erectile dysfunction: A randomized, double-blind, placebo-controlled trial. The Journal of Urology, 185(1), 243–248. https://doi.org/10.1016/j.juro.2010.09.035
  • Hatzichristou, D., Gambla, M., Rubio-Aurioles, E., Buvat, J., Brock, G. B., Spera, G., Rose, L., Lording, D., & Liang, S. (2008). Efficacy of tadalafil once daily in men with diabetes mellitus and erectile dysfunction. Diabetic Medicine, 25(2), 138–146. https://doi.org/10.1111/j.1464-5491.2007.02338.x
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