Viagra dosage and strength
Viagra comes in strengths of 25 mg, 50 mg, and 100 mg. Most men are prescribed a dose of 50 mg, but lower and higher doses are available to suit different situations. You should never exceed the dose you were prescribed. If you feel your dose is wrong, speak to us rather than changing it yourself.
Viagra contraindications
DO NOT take Viagra if you:
- Are under 18 years old
- Are a woman
- Don’t have erectile dysfunction
- Have been advised by your doctor to avoid sexual activity
- Are allergic to Sildenafil Citrate or any of the other ingredients in the medication (see the leaflet in the Viagra packaging for a full list of ingredients)
- Are taking nitrate medicines
- Are taking medicines called nitric oxide donors such as amyl nitrite (poppers)
- Are taking guanylate cyclase stimulators like Adempas (riociguat), for hypertension
- Have had surgery in the last six months
- Have recently had a heart attack or stroke
- Have low blood pressure, or high blood pressure which is not controlled
- Have inherited eyes diseases, like retinitis pigmentosa
- Have ever had a loss of vision caused by non-arteritic anterior ischaemic optic neuropathy (NAION)
Talk to us if you are unsure if you can take Viagra.
Taking other medications with Viagra
Viagra can interact with other meds. Don’t take it if you are taking any of the medications listed in Viagra interactions. You should also tell your prescriber about any other medications you are taking, including vitamins and herbal supplements.
Viagra interactions
DO NOT take Viagra if you are taking:
- Other erectile dysfunction treatments, including any pills or creams or ointments
- Any treatments for pulmonary arterial hypertension (PAH) containing Sildenafil or other PDE5 inhibitors
- Nitrate medicines, often prescribed for chest pain
- Guanylate cyclase stimulators like Adempas (riociguat), prescribed for hypertension
- Medicines called alpha-blockers
- Medicines called HIV protease inhibitors
- Medicines to treat high blood pressure
Viagra and grapefruit
Don’t eat grapefruit or drink grapefruit juice if you’re taking Viagra. Research has shown that grapefruit juice contains a molecule that can both delay the effects of Viagra and also make them stronger. This could interfere with how your Viagra works and could lead to you experiencing more severe side effects.
Who can take Viagra?
Viagra can be taken by adult men over the age of 18 who have ED. It isn’t suitable for everyone though, and you should check with us before taking it if you:
- Have blood cells conditions like sickle cell disease, multiple myeloma, or leukaemia
- Have a deformity of the penis, such as Peyronie’s Disease
- Have heart problems
- Have liver problems
- Have kidney problems or are having dialysis
- Have pulmonary hypertension
- Have problems with bleeding
- Have had stomach ulcers
Viagra and driving and using machines
Viagra can cause side effects which can impair your ability to drive and use machinery, such as dizziness and vision problems. If you experience these side effects, you shouldn’t drive or use any machinery. Only do so when you’re sure how your body reacts to the meds and that you don’t experience these side effects.
Possible side effects of Viagra
Just like any other medication, Viagra can have side effects, which vary from man to man. You might get some or none at all. It all depends on you as a person. These were the side effects found in clinical testing:
Common side effects of Viagra (may affect up to 1 in 10 people):
- Headache (very common, may affect more than 1 in 10 people)
- Nausea
- Facial flushing
- Hot flushes
- Indigestion
- Visual disturbances, including seeing colour tinges and blurred vision
- Stuffy nose
- Dizziness
Uncommon side effects of Viagra (may affect up to 1 in 100 people):
- Vomiting
- Skin rash
- Eye effects, including eye irritation, bloodshot eyes/red eyes, eye pain, seeing flashes of light, visual brightness, light sensitivity, and watery eyes
- Pounding heartbeat and rapid heartbeat
- High blood pressure and low blood pressure
- Muscle pain
- Feeling sleepy
- Feeling tired
- Reduced sense of touch
- Vertigo
- Ringing in the ears
- Dry mouth
- Blocked or stuffy sinuses
- Runny nose, sneezing, and stuffy nose
- Upper abdominal pain
- Reflux/heartburn
- Presence of blood in urine
- Pain in the arms or legs
- Nosebleed
- Feeling hot
Rare effects of Viagra (may affect up to 1 in 1,000 people):
- Fainting
- Stroke
- Irregular heartbeat
- Heart attack
- Temporarily decreased blood flow to parts of the brain
- A feeling of tightening of the throat
- Numb mouth
- Eye effects, including bleeding at the back of the eye, double vision, reduced sharpness of vision, abnormal sensation in the eye, swelling of the eye or eyelid, small particles or spots in your vision, seeing halos around lights, dilation of the pupil of the eye, and discolouration of the whites of the eye
- Penile bleeding
- Presence of blood in semen
- Dry nose
- Swelling of the inside of the nose
- Feeling irritable
- Sudden decrease or loss of hearing
If you experience any of the following side effects stop taking Viagra and seek medical help immediately:
- The rapid onset of allergic reaction side effects, such as flushing, itchy skin and/or a rash, sudden wheeziness, swelling of the lips, face, neck, and throat making it difficult to breathe
- Chest pains
- An erection that lasts for longer than four hours
- A sudden decrease or loss of vision
- Seizures or fits
Although rare, unstable angina (a heart condition) and sudden death have been reported after taking Viagra. Most of the men who experienced these side effects had pre-existing heart problems.
How long can I keep Viagra tablets for?
You can keep Viagra tablets up until the date of expiry on the packaging (the expiry date refers to the last day of the month). Never use any ED meds after the expiry date.
How to store Viagra tablets at home or when travelling
Whether at home or travelling, keep your Viagra in its original packaging to avoid any moisture getting to the tablets. Also make sure you store your meds in a cool, dry place and keep them below a temperature of 30°C. Wherever you store your ED meds, always keep them out of sight and reach of children.
How to dispose of unused Viagra tablets
Although it might seem like the easy option, don’t just throw your unwanted or expired meds in the bin with your household waste. You also shouldn’t flush them down the sink or toilet, as medication can cause harm to the environment. To get rid of them responsibly and safely, take them to your local pharmacy.
Arrange a check-up with your GP after 6 months
Make sure you book in with your GP for a check-up after you’ve been taking Viagra for six months. Even if it’s working and you feel healthy, it’s important not to miss this appointment. ED may be an early sign of something much more serious, including heart problems, high cholesterol, high blood pressure, and diabetes. It’s important to rule these conditions out.