Is Viagra safe? The rules on its label
Its safety depends on who takes it and what else they take, and the label spells out who must not. Sildenafil, the medicine in Viagra, is prescription-only in Australia: a doctor assesses you before prescribing it (healthdirect). These are the rules that decide whether it is safe for you.
| Rule | Why |
|---|---|
| Never with nitrates (angina medicines) or amyl nitrite ("poppers") | Together they can cause "a sudden drop in your blood pressure that is hard to treat" (healthdirect). This is the one rule with no exceptions. |
| Not where sex itself is a risk to the heart | It "must not be used where sexual activity is inadvisable (e.g. men with severe heart disease such as unstable angina or severe heart failure)" (EMA). |
| Not within 6 months of a heart attack or stroke, or with blood pressure that is unusually high or low | Both are on the leaflet's "Do not take" list, with severe liver problems (Viagra CMI). |
| Not with riociguat, or after vision loss from NAION, or with retinitis pigmentosa | Named in the European label (EMA). |
| One tablet in 24 hours at most | "You should not take any more than one sildenafil tablet in 24 hours" (healthdirect). |
| An erection lasting more than 4 hours | Go to the nearest hospital emergency department (healthdirect). |
Sources: healthdirect — Sildenafil (Viagra); Viagra CMI; EMA — Viagra. Blood-pressure medicines and alpha-blockers also interact with it; every combination is in our guide to Viagra with other medicines.
Can you travel with Viagra, on a plane or abroad?
Each travel question has its own page; this guide takes no position on airline, customs or import rules. Flying with ED tablets is taken up in can you travel with Viagra on a plane?, and the destinations in can I bring Viagra to Thailand?, bringing Viagra into the USA through customs and on a plane and can Viagra be taken across the border?
What we can state is the medicines' status in Australia. Sildenafil and tadalafil "can only be supplied to Australians with a prescription", and products not listed in the Australian Register of Therapeutic Goods (ARTG) "are not approved for supply in Australia, have not been reviewed for safety or quality" (TGA). Viagra is on the ARTG; Kamagra is not.
What happens if you take expired Viagra?
It may be weaker, and it could be unsafe: the Australian leaflet says "Do not take this medicine after the expiry date." (Viagra CMI). "Medicines lose their effectiveness over time because they are made up of chemicals that break down as time passes", and "They may also become dangerous due to a change in their chemical makeup"; you can return them to your local pharmacy (healthdirect). A weaker tablet is no reason to take a second one — one in 24 hours is the limit. Until the date on the pack, store Viagra below 30°C in a cool, dry place. The details are in what happens if you take expired or out-of-date Viagra?, and for tadalafil in does expired Cialis still work?
Is it safe for a healthy man to take Viagra?
It is not made for that: Viagra "is used to treat adult men with erectile dysfunction" (EMA), and in Australia a doctor decides whether you need it. It works only with sexual stimulation, and it has side effects: headache, facial flushing, a blocked nose and indigestion are common; changes in vision, an erection that will not go down and sudden hearing loss are rarer and serious (healthdirect). More in is it safe for a healthy man to take Viagra?
It is not for teenagers either: "VIAGRA is not indicated for individuals below 18 years of age" (EMA product information) — see can minors take Viagra?
Does Viagra affect the heart, and is it safe for heart patients?
It lowers blood pressure a little, and it is ruled out for men whose heart cannot take the strain of sex. The European label says sildenafil causes "mild and transient decreases in blood pressure" (EMA product information); the danger comes when something else lowers it too — nitrates above all. The Australian leaflet says do not take it if "you have heart or blood vessel problems that make sexual intercourse inadvisable", or have had a heart attack or stroke in the last 6 months (Viagra CMI), and healthdirect adds: avoid ED medicines if sexual exertion could put you at risk. Whether Viagra suits your heart is a question for your GP or cardiologist, who knows your medicines. The heart questions are answered in does Viagra affect the heart, and is it safe for heart patients?; the medicines in can nitrates be taken with Viagra? and can you take Viagra after a heart attack or with heart medication?
Can Viagra cause death?
Deaths have been reported after sildenafil, mostly in men who already had heart risk factors, and the label says it cannot be determined whether the medicine caused them. In its words: "Serious cardiovascular events, including myocardial infarction, unstable angina, sudden cardiac death … have been reported post-marketing in temporal association with the use of VIAGRA. Most, but not all, of these patients had pre-existing cardiovascular risk factors" (EMA product information). Read it together with the heart rules above. What is known about the cases: can Viagra cause death or sudden death?
How can you tell real Viagra from a fake?
Start with the pack: the name on it should be on the ARTG. Viagra is listed there as 25, 50 and 100 mg tablets, and anyone can search the ARTG. The Australian leaflet describes the 50 mg tablet as "blue, rounded diamond shaped film coated tablets, debossed with 'VGR 50'" — VGR 25 and VGR 100 for the other strengths (Viagra CMI). The checks, step by step, are in how to identify real and fake Viagra pills, and the colour question in what colour are Viagra pills?
healthdirect is blunt about the risk: "Some people buy sildenafil online without a prescription. This isn't a good idea, as you can't be sure whether these pills contain the medicine or are counterfeit" (healthdirect). What a fake can do is covered in what are the dangers of counterfeit Viagra?; "herbal" pills with hidden sildenafil are in our natural Viagra guide. Kamagra, which we sell, is not on the ARTG; what that means before you order is on our Kamagra page.
Are Hims ED pills legitimate? And the other questions
Three more questions have their own pages. Whether a telehealth brand's tablets are the real medicine: are Hims ED pills effective and legitimate? How members of the armed forces get ED medicines, a question asked mostly about the US military: can military personnel use and access Viagra? And why generic sildenafil is sold alongside Viagra: when does the patent for Viagra expire? — generic and brand are compared in our comparisons guide.
Sources
- healthdirect — Erectile dysfunction medicines; healthdirect — Sildenafil (Viagra) (both last reviewed February 2025); healthdirect — Out-of-date medicines (last reviewed September 2024)
- Viagra Consumer Medicine Information (Australia) (prepared October 2024)
- EMA — Viagra, medicine overview (updated 17 September 2025); EMA — Viagra product information
- TGA — NSW individual fined for alleged offences relating to unapproved erectile dysfunction medicines (20 February 2024); TGA — Australian Register of Therapeutic Goods search (searched 25 September 2026)
