What are the most common side effects?

It’s important to know that not everyone experiences side effects. Many men use erectile medication without any complaints. When side effects do occur, they are usually mild and well tolerated. The most commonly reported side effects with both sildenafil and tadalafil are⁷,⁸:

Headache: This is the most frequently reported side effect. It occurs because blood vessels dilate - the same mechanism that improves erections. The headache is usually mild and disappears within a few hours.

Flushing and warmth: Your face may become red and feel warm. This is caused by increased blood flow to the skin. It’s temporary and harmless.

Nasal congestion: The nasal lining can swell due to blood vessel dilation. A blocked or runny nose is a common but harmless side effect.

Stomach upset: Nausea, heartburn, or stomach pain may occur. This can often be reduced by taking the medication with a light meal.

Back pain or muscle pain: Especially with tadalafil, some users report pain in the lower back or legs. The exact cause isn’t fully understood, but it usually resolves on its own.

Dizziness: Because these medications can lower blood pressure slightly, you may feel lightheaded. This is usually mild - stand up slowly after sitting or lying down.

How long do side effects usually last?

The duration of side effects is related to how long the medication remains active in your body. With sildenafil, which works for 4–6 hours, side effects usually resolve within the same timeframe. Often, they become less noticeable after 2–3 hours.

With tadalafil, which can work for up to 36 hours, side effects may last longer. This doesn’t mean you’ll have a headache for 36 hours - the intensity usually decreases quickly - but mild symptoms may persist longer than with sildenafil.

Importantly, side effects often decrease with repeated use as your body adapts to the medication. What feels noticeable the first few times may become barely perceptible after a week or two.

Are side effects different between sildenafil and tadalafil?

Both medications have largely similar side effects because they work in a similar way³. Still, there are subtle differences.

Sildenafil slightly more often causes:
• Facial flushing
• A temporary blue tint to vision (very rare)
• Shorter-lasting side effects (4–6 hours)

Tadalafil relatively more often causes:
• Back pain or muscle aches in the legs
• Longer-lasting side effects (due to its 36-hour duration)
• With daily use: often milder side effects because of the lower dose

These differences are small. Most men experience similar side effects with both medications. However, on an individual level, you may tolerate one better than the other.

How can you reduce side effects?

There are several ways to limit or prevent side effects:

Start with a low dose: Begin with 50 mg sildenafil or 10 mg tadalafil. If this works well, a higher dose isn’t necessary. Higher doses increase the risk of side effects without always providing more benefit.

Watch your meals: Fatty meals can slow absorption and may worsen side effects. Take the medication on an empty stomach or with a light meal if possible.

Limit alcohol: Alcohol enhances the blood pressure–lowering effect, which can worsen dizziness and headache. Limit intake to one or two drinks.

Stay hydrated: Drink enough water. Dehydration can make headaches worse.

Timing: Take sildenafil about one hour before sex so peak levels coincide with sexual activity. This maximizes effectiveness and may reduce side effects.

Consider daily tadalafil: If you experience significant side effects with on-demand use, daily tadalafil (5 mg) may help. Because the dose is lower, side effects are often milder.

When are side effects dangerous?

Most side effects are harmless, but certain situations require immediate medical attention. Be aware of these warning signs:

Priapism (erection lasting longer than 4 hours): This is a medical emergency. An erection lasting more than 4 hours without sexual stimulation can cause permanent damage to erectile tissue. Seek immediate medical help.

Sudden vision changes: If you suddenly experience blurred vision, changes in color perception, or partial vision loss, stop the medication and contact a doctor immediately. This is very rare but serious.

Hearing loss: Sudden hearing loss or ringing in the ears can occur, although rarely. Stop the medication and seek medical care.

Chest pain: Chest pain during or after use may indicate heart problems and requires immediate medical evaluation. Never use nitrates (heart medication) together with erectile medication.

Severe allergic reaction: Skin rash, itching, swelling of the face or throat, or difficulty breathing are signs of an allergic reaction. Seek emergency care immediately.

When should you contact a doctor? In addition to emergency situations, consult your doctor if:

Side effects don’t improve: Mild side effects during the first few uses are normal. If they remain just as strong after one or two weeks, talk to your doctor. A lower dose or a different medication may be better.

The medication doesn’t work: No effect after 3–4 attempts? Discuss this with your doctor. A different dose, another active ingredient, or a combined approach may help.

Other medications change: Some medications interact with erectile drugs. Always inform your doctor which erectile medication you’re using so potential interactions can be assessed.

New health issues arise: If you develop heart problems, blood pressure issues, or other new medical conditions, have your doctor review whether continued use is safe.

Research shows that erectile medication is safe for most men when used correctly⁵,⁶. If you’re unsure about anything, contact your doctor - it’s always better to check than to take unnecessary risks.

Safe and effective use

For most men, erectile medication is a safe and effective solution. Side effects are usually mild and not a reason to avoid treatment. By paying attention to dosage, timing, and alcohol intake, you can often minimize discomfort.

What matters most: for nearly all users, the benefits of effective treatment far outweigh the inconvenience of mild side effects. Just be aware of the rare warning signs that require immediate medical attention.

At Menkind, you receive guidance from registered doctors who help you choose the right treatment and adjust it if needed.

References

1. Carson, C. C., et al. (2004). The efficacy and safety of tadalafil: an update. BJU International, 93(9), 1276-1281. https://pubmed.ncbi.nlm.nih.gov/15180622/

2. Brock, G. B., et al. (2002). Efficacy and safety of tadalafil for the treatment of erectile dysfunction: results of integrated analyses. The Journal of Urology, 168(4), 1332-1336. https://pubmed.ncbi.nlm.nih.gov/12352386/

3. Saigal, C. S., et al. (2006). "Predictors and prevalence of erectile dysfunction in a racially diverse population." Archives of Internal Medicine, 166(2), 207-212. https://pubmed.ncbi.nlm.nih.gov/16432090/

4. McMahon, C. G. (2005). Comparison of efficacy, safety, and tolerability of on-demand tadalafil and daily dosed tadalafil for the treatment of erectile dysfunction. The Journal of Sexual Medicine, 2(3), 415-425. https://pubmed.ncbi.nlm.nih.gov/16422873/

5. Jackson, G., et al. (2005). Past, present, and future: a 7-year update of Viagra (sildenafil citrate). International Journal of Clinical Practice, 59(6), 680-691. https://pubmed.ncbi.nlm.nih.gov/15924597/

6. Porst, H. (2002). IC351 (tadalafil, Cialis): update on clinical experience. International Journal of Impotence Research, 14(Suppl 1), S57-S64. https://pubmed.ncbi.nlm.nih.gov/11850737/

7. Apotheek.nl. Sildenafil bijsluiter. https://www.apotheek.nl/medicijnen/sildenafil 

8. Apotheek.nl. Tadalafil bijsluiter. https://www.apotheek.nl/medicijnen/tadalafil