Is generic sildenafil the same as Viagra?
Yes — sildenafil is the medicine in Viagra. Viagra is a trade name for sildenafil, a prescription medicine for erectile dysfunction, and other brands of the same medicine are also available in Australia (healthdirect — Sildenafil (Viagra)). Viagra has been on the Australian Register of Therapeutic Goods (ARTG) since 1998, as 25, 50 and 100 mg tablets (ARTG search), and its Australian sponsor is Viatris (Viagra consumer medicine information).
The tablets on this page are generic sildenafil in the same three strengths: 25, 50 and 100 mg. "Generic" means they are sold under the medicine's name, sildenafil, not as Viagra. The doses, the rules for taking it, the people who must not take it and the side effects are those of sildenafil, whatever name is on the pack.
How does sildenafil work?
Sildenafil relaxes the blood vessels in the penis when you are sexually excited, so more blood can flow in and an erection can happen (Viagra CMI). It belongs to the PDE5 inhibitors, the group of erectile dysfunction medicines available in Australia, alongside tadalafil, vardenafil and avanafil (healthdirect — Erectile dysfunction medicines). Two practical points follow:
- It needs arousal. Sexual stimulation is required for it to work; a tablet on its own does nothing (EMA).
- It works for hours, not days. It usually starts working in 30 to 60 minutes, and its effects can last up to 4 hours (healthdirect).
Sildenafil is a treatment for erectile dysfunction — trouble getting or keeping an erection. It is not made to delay ejaculation. Whether it helps you last longer is answered in does Viagra make you last longer in bed?, and the medicines aimed at coming too soon are in our guide to pills to last longer.
How much does generic sildenafil cost?
The price table at the top of this page is the current price list, in Australian dollars, with one tab for each strength: 25, 50 and 100 mg. Within each strength the price per tablet falls as the pack gets bigger, so compare the per-tablet column, not the pack total. Prices are read live when the page loads.
Pick the strength before the pack. The usual starting dose is 50 mg, 25 mg is the lower dose and 100 mg is the maximum — the dosage table below explains when each one applies.
Do you need a prescription for sildenafil in Australia?
Yes. Sildenafil is a prescription-only medicine in Australia. You need a prescription from a doctor to get it, and the doctor assesses you first, because it is not suitable for people with certain medical conditions (healthdirect — sildenafil, healthdirect — ED medicines). The TGA says the same: sildenafil "can only be supplied to Australians with a prescription" (TGA, February 2024). That covers Viagra and every generic.
The rule behind it is safety, and one point outweighs the rest: never take sildenafil if you use nitrates — angina medicines such as glyceryl trinitrate sprays or tablets. Together they can cause a severe drop in blood pressure that may be difficult to treat (Viagra CMI). The full list is under who must not take sildenafil. If you have no prescription, see your GP: that is the person who can check whether sildenafil is safe with your heart, your blood pressure and the medicines you already take.
Can you buy Viagra over the counter in Australia?
No. Every erectile dysfunction medicine needs a prescription in Australia, so sildenafil, tadalafil, vardenafil and avanafil are not sold over the counter (healthdirect). That includes Viagra and every generic sildenafil. Herbal products marketed as "natural Viagra" are a separate category; what is known about them is in our natural Viagra guide.
Is it safe to buy sildenafil online?
The risk online is the tablet itself. healthdirect warns against buying sildenafil online without a prescription, because you cannot be sure whether the pills contain the medicine or are counterfeit — and counterfeit medicines can be very dangerous (healthdirect). The TGA adds that products not listed in the ARTG are not approved for supply in Australia and have not been reviewed for safety or quality (TGA). Four checks that are yours to make, whoever you buy from:
- Look up the name on the pack. Anyone can search the ARTG — Viagra is listed there, and a product that is not has not been assessed by the TGA.
- Know your dose before you order: 50 mg to start, 100 mg at most, one dose a day.
- Tell your GP everything you take, above all nitrates, amyl nitrite ("poppers") and blood-pressure medicines.
- Know where the parcel comes from. Orders from this shop are sent from India or Hong Kong.
Sildenafil dosage: 25, 50 or 100 mg?
The recommended dose is 50 mg, which can be raised to a maximum of 100 mg or lowered to 25 mg depending on how well it works and which side effects you get (EMA). Your doctor prescribes the dose that suits your situation (healthdirect).
| Strength | Place in the label | When it applies |
|---|---|---|
| 25 mg | The lower dose | When 50 mg causes side effects that bother you |
| 50 mg | The recommended dose | Starting sildenafil |
| 100 mg | The maximum dose | When 50 mg does not work well enough |
Whatever the strength, take no more than one tablet in 24 hours (healthdirect). A second tablet the same day, or more than 100 mg at once, is above the maximum.
How to take sildenafil
Swallow one tablet whole with a full glass of water, about one hour before sex (Viagra CMI).
- Timing. It normally takes between half an hour and one hour to start working, and the time varies from person to person (Viagra CMI).
- Food. Taken with a heavy meal, it can take longer to work (EMA, Viagra CMI).
- Alcohol. Be careful: drinking alcohol can itself temporarily make it harder to get an erection (Viagra CMI).
- Driving. If sildenafil makes you dizzy or changes your vision, do not drive (Viagra CMI).
- Other ED treatments. If you already use another treatment for erectile dysfunction, check with your doctor first (Viagra CMI).
Who must not take sildenafil
Sildenafil is not for you if any of the following is true (EMA, healthdirect, Viagra CMI):
- you use nitrates for angina or chest pain, amyl nitrite, or a guanylate-cyclase stimulator such as riociguat;
- you have recently had a heart attack or stroke, or your heart could not safely take the exertion of sex;
- your blood pressure is unusually high or low, or is not effectively treated;
- you have severe liver disease;
- you have an inherited eye condition such as retinitis pigmentosa, or have lost sight in the past from NAION (reduced blood flow to the optic nerve).
Blood-pressure and prostate medicines need a doctor's check first. healthdirect lists blood-pressure medicines among those that can combine with sildenafil to cause a sudden drop in blood pressure that is hard to treat, and the Viagra leaflet lists alpha-blockers — used for high blood pressure or prostate problems — among the medicines that may interfere with it. Two common combinations have their own guides: sildenafil with amlodipine and other blood-pressure medicines and alfuzosin with sildenafil. Sildenafil is not for use in women (Viagra CMI).
Generic sildenafil or brand Viagra: what differs?
The medicine is the same; the name on the pack, the maker and the price are not. What to compare:
| Viagra (brand) | Generic sildenafil | |
|---|---|---|
| Active ingredient | sildenafil | sildenafil |
| Strengths | 25, 50 and 100 mg | 25, 50 and 100 mg on this page |
| On the ARTG? | Yes, since 1998 | Depends on the brand — search its name on the ARTG |
| Prescription in Australia | Required | Required |
| Dose, timing, who must not take it | The same rules — they belong to sildenafil, not to the brand | |
A higher price does not make one sildenafil stronger than another: 100 mg is 100 mg. The same goes for Kamagra, which is also sildenafil but is not included in the ARTG.
Sildenafil side effects
The most common side effects are headache, flushed skin, a stuffy or runny nose, indigestion or heartburn, and dizziness; back pain and muscle aches also occur. They usually go away after a few hours (healthdirect).
Serious side effects are rarer: changes in or loss of vision, sudden hearing loss, dizziness or fainting, seizures, migraines and allergic reactions (healthdirect — ED medicines, healthdirect — sildenafil). Any of them needs medical help straight away. An erection that lasts more than 4 hours needs the nearest hospital emergency department: prolonged erections can be dangerous.
Sildenafil vs Kamagra, Cialis and vardenafil
| Medicine | Active ingredient | On the ARTG? | When to take it | How long it can work |
|---|---|---|---|---|
| Viagra / generic sildenafil | sildenafil 25, 50 or 100 mg | Viagra: yes | About 1 hour before sex, once a day at most | Up to 4 hours |
| Kamagra | sildenafil 50 or 100 mg; oral jelly 100 mg | No | As sildenafil | As sildenafil |
| Cialis / generic tadalafil | tadalafil 2.5, 5, 10 or 20 mg | Cialis: yes | At least 30 minutes before sex (allow 1 hour the first time), or a low dose once a day | Up to 36 hours |
| Generic vardenafil | vardenafil 5, 10 or 20 mg | Yes (the Levitra brand is not) | As prescribed | — |
Sources: ARTG search, healthdirect (sildenafil), EMA (tadalafil), Cialis consumer medicine information. Every one of them is prescription-only in Australia. The real choice is timing: sildenafil suits sex you can plan an hour ahead, tadalafil a longer window. What causes erectile dysfunction, and the options besides tablets, are in our erectile dysfunction overview.
Delivery to Australia
Every order is dispatched from India or Hong Kong, not from an Australian warehouse, and there is no shopfront. Express parcels take 5–9 days and regular parcels 10–14 days; orders from A$320 ship free. The full terms are on the delivery conditions page.
Sources
- healthdirect — Sildenafil (Viagra) (last reviewed February 2025), read 25 September 2026
- healthdirect — Erectile dysfunction medicines (last reviewed February 2025)
- Viagra Consumer Medicine Information (Australia), Medsinfo (prepared October 2024), read 25 September 2026
- TGA — Australian Register of Therapeutic Goods (search: Viagra, Cialis, vardenafil, Levitra, Kamagra), read 25 September 2026
- TGA — NSW individual fined for alleged offences relating to unapproved erectile dysfunction medicines (20 February 2024)
- European Medicines Agency — Viagra (sildenafil): EPAR medicine overview
- European Medicines Agency — Cialis (tadalafil): EPAR medicine overview
