Can you take multiple Viagra pills safely?

Can you take multiple Viagra pills safely? No: the dose is one tablet, once a day at most, and 100 mg is the ceiling. Taking two or more at once does not give a better erection. In studies, 200 mg worked no better than lower doses but caused more side effects, and single doses of up to 800 mg brought the same side effects, more often and more severely. If you have taken too many, the Australian leaflet says to phone the Poisons Information Centre on 13 11 26 straight away.

How many Viagra tablets can you take at once?

One. The Australian leaflet's dose is one tablet a day, of 25, 50 or 100 mg, chosen by your doctor "depending on your condition and response", and it says: "Do not take more than one dose of VIAGRA a day" (Viagra CMI). The usual dose starts at 50 and can be raised to 100 mg or lowered to 25 mg; 100 mg is the maximum recommended dose, and once a day the maximum frequency (EMA product information). healthdirect puts it the same way: no more than one sildenafil tablet in 24 hours (healthdirect). A second tablet later the same day is answered in can I take Viagra twice in one day?

Would two tablets work better than one?

No. Between 25 and 100 mg, the amount of sildenafil in the blood rises in step with the dose, but doses of 200 mg "did not result in increased efficacy" (EMA product information). The European leaflet says it plainly: "Doses above 100 mg do not increase the efficacy", and "You should not take more tablets than your doctor tells you to" (EMA package leaflet). Two tablets of the starting strength hold as much sildenafil as one 100 mg tablet, but that is a dose change for your doctor to make, not a way round the limit; see the difference between 50 mg and 100 mg Viagra. If one tablet is not enough, the leaflet's advice is to tell your doctor, who "may decide that you need a higher dose" (Viagra CMI). Other things that help are in how to increase the effects of Viagra.

What happens if you take too many?

More of the same side effects, and worse. In single-dose studies in volunteers of up to 800 mg, side effects were similar to those at lower doses, but more frequent and more severe; at 200 mg, headache, flushing, dizziness, indigestion, a blocked nose and altered vision all became more common (EMA product information). There is no antidote: the label's treatment is "standard supportive measures", and kidney dialysis does not speed up clearance, because sildenafil is highly bound to proteins in the blood. Sildenafil also lowers blood pressure a little on its own, by 8.4/5.5 mmHg on average after 100 mg (EMA product information), and with nitrates, the medicines for angina, the drop can be sudden and hard to treat (healthdirect). An erection that lasts more than 4 hours needs the nearest hospital emergency department (healthdirect).

What should you do if you have taken too many?

Get advice now rather than waiting to see. The Australian leaflet says to immediately phone the Poisons Information Centre on 13 11 26, contact your doctor, or go to the emergency department at your nearest hospital, and to do this "even if there are no signs of discomfort or poisoning" (Viagra CMI). Tell your doctor or go straight to the emergency department if you notice chest pain, fainting, an unusual or fast heartbeat, sudden vision problems, or an erection that is painful or lasts longer than four hours (Viagra CMI). Do not take another tablet in the next 24 hours (healthdirect).

Can you take Viagra with another ED tablet?

No. The safety and efficacy of sildenafil combined with other PDE5 inhibitors, with Revatio (the sildenafil brand for high blood pressure in the lungs) or with other treatments for erectile dysfunction "have not been studied", so the label does not recommend it (EMA product information). The European leaflet also says not to take Viagra tablets with any other sildenafil product (EMA package leaflet), and the Australian leaflet asks you to tell your doctor if you use "any other treatment for impotence" (Viagra CMI). More in can you mix Viagra and Cialis?

Can other medicines act like a double dose?

Some can, by slowing the breakdown of sildenafil in the liver. With the antibiotic erythromycin, exposure to a 100 mg dose rose by 182%; with the HIV medicine ritonavir it rose elevenfold, and levels were still high 24 hours later. Sildenafil is not advised with ritonavir, and with medicines of this kind a 25 mg starting dose should be considered (EMA product information). Grapefruit juice may raise levels modestly. See can you take Viagra with antibiotics?, does grapefruit juice enhance the effects of Viagra? and the half-life of Viagra.

The short answer

One tablet, once a day, 100 mg at most. Taking more does not make Viagra work better; it brings more side effects. If you have taken too many, phone the Poisons Information Centre on 13 11 26 or go to the nearest emergency department, even if you feel fine. More in our guide to Viagra and Cialis with other medicines.