Viagra is used to treat erectile dysfunction (ED), but it wasn’t always intended for this purpose. It was created by Pfizer to treat hypertension and angina, but it turned out to be more successful at inducing erections than helping patients with their heart. 

So, the little blue pill was launched, and since then, it’s gone on to help millions of men regain their confidence in the bedroom and enjoy a fulfilling sex life.  

How does Viagra work

Viagra contains the active ingredient sildenafil citrate, which is part of a group of drugs known as PDE5 inhibitors. It works by relaxing the smooth muscles that line the blood vessels at the base of the penis to increase blood flow

This expands the tissue in the penis for a hard, long-lasting erection. 

Who can take Viagra? 

Viagra is well tolerated by most men, but it isn’t suitable for everyone. In some people, it can interfere with their other medications and cause dangerous side effects. 

Some of the reasons for which you should not take Viagra is if you are:   

  • Allergic to sildenafil or any of the ingredients listed on the pack
  • Taking any medicine that contain nitrates for the treatment of chest pain
  • Using nitric oxide donors (also called “poppers”) 
  • Taking Riociguat to treat high blood pressure in the lungs 

Tell your doctor or pharmacist if you have a severe liver or heart problem, you’ve recently had a stroke or heart attack, you suffer with low blood pressure, or you have any problems with your eyes or ever had a loss of vision.  

How to take Viagra

If you’re taking Viagra for the first time then undoubtedly, you’ll have lots of questions, so in this section we answer the top five most frequently asked by our patients:  

How much Viagra should I take?
Viagra comes in strengths of 25mg, 50mg, and 100mg.
For those who are new to this treatment, the recommended dose is 50mg. Your doctor may decide that you need a lower strength depending on your age and health.
You should never take more than one dose of Viagra in any 24-hour period.  

How long does Viagra take to work?
Viagra usually takes effect within 60 minutes, but in some people, it can be as quick as 30 minutes or less. We recommend taking it at least one hour before sexual activity.
It remains active in your system for between four to five hours, so you can take it earlier if you wish, but its potency will start to fade the longer you leave it to have sex.  

Can I take Viagra with food?
It’s best to take Viagra on an empty stomach, but if this isn’t possible, stick to a light meal. Food slows down the absorption of the medicine and can delay its effects.  

Can I drink alcohol with Viagra?
Alcohol doesn’t directly interact with Viagra, but it is a known cause of erectile dysfunction so drinking would be counterproductive. For the best results, limit your alcohol intake to two to three units (one or two drinks). 

Do I need to be sexually aroused?
It’s important to remember that Viagra only works if you are sexually aroused. Without stimulation you won’t be able to achieve an erection. If you’re suffering from low libido, contact your GP or make an appointment with a sexual health specialist. 

viagra tablets in packet

The side effects of Viagra 

Like all prescription drugs, there are some side effects to taking Viagra. Not everyone will experience these unwanted symptoms, but you should be aware of them.   

The most common side effects include: 

  • Facial flushing 
  • Nasal congestion 
  • Headaches 
  • Indigestion 
  • Nausea

In most cases, the side effects are mild and wear off quickly. It is possible to suffer an allergic reaction to Viagra. If you experience any of the following symptoms, you should stop taking the tablets and seek immediate medical attention

  • Sudden wheeziness 
  • Dizziness
  • Difficulty breathing 
  • Swelling of the eyelids, face, lips, or throat 

Erectile dysfunction medication can cause a painful and prolonged erection in rare cases. If this happens, seek the help of an experienced healthcare professional. It may be difficult to talk about, but left untreated it can permanently damage the penis.  

Alternatives to Viagra

Pfizer’s patent on Viagra expired in 2013, which has allowed other manufacturers to use the same formula to make their own generic versions of the pill. 

Sildenafil – the unbranded alternative to Viagra – is cheaper to buy and just as effective. 

Other ED medications available to buy from Post My Meds include: 

These tablets are all PDE5 inhibitors, so they work in the same way as Viagra by increasing blood flow to the penis. Though they are part of the same class of drugs, their active ingredients are different and some men find that they get on better with one brand over another – the only way of knowing which is better, is to try for yourself. 

You should never take more than one erectile dysfunction tablet at the same time. Leave at least 24 hours between each dose.

The key takeaway how to take Viagra  

Viagra is an effective treatment for erectile dysfunction. For the best results it should be taken on an empty stomach one hour before you plan to have sex. You can expect it to start working within 30 to 60 minutes, but for it to work you must be aroused. 

Before you can buy Viagra, your pharmacist or GP will ask you about any other medications you are taking and your medical history to ensure it’s safe for you to take.  

Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Nov 30, 2021 by Joseph Issac, MPharm
Reviewed Nov 30, 2021 by Prabjeet Saundh, MPharm