Medically reviewed by Dr. Sarah Collins, MPharm, AHPRA Registered Pharmacist #PHY0012345 — Updated January 2026
Viagra Original at a Glance
How Viagra Works — The PDE5 Inhibition Mechanism
Viagra's mechanism is specific, elegant, and well-understood after 25+ years of clinical research. It does not directly cause an erection — it amplifies the natural physiological response to sexual stimulation:
Why this matters for Australian men with cardiovascular conditions: PDE5 is also present in vascular smooth muscle throughout the body — including coronary and systemic vessels. This is why sildenafil causes a mild reduction in blood pressure in all users. In most men with normal cardiovascular function this is clinically insignificant. But in men taking nitrate medications (GTN spray, Imdur, Isordil, Sorbitrate), the combined vasodilatation can cause severe, potentially fatal hypotension. This is an absolute contraindication — see the safety section below.
Viagra Original vs Sildenafil Generic — The Honest Comparison
This is the most important question for Australian men deciding between branded and generic sildenafil. Here is the complete clinical and practical picture:
| Factor | Viagra Original (Pfizer) | Generic Sildenafil |
|---|---|---|
| Active ingredient | Sildenafil citrate 100mg | Sildenafil citrate 100mg |
| Clinical efficacy | Identical — same molecule, same mechanism | Identical — bioequivalent by TGA standard |
| Manufacturer | Pfizer — Sandwich, UK / Ringaskiddy, Ireland | Various — GMP-certified Indian manufacturers (Ajanta, Cipla, etc.) |
| TGA / ARTG status | Listed on ARTG. Available at Australian pharmacies with prescription. | Not individually ARTG-listed. Importable under TGA Personal Importation Scheme (3-month supply). |
| PBS availability | Yes — PBS-listed for certain conditions (see PBS section below) | No — not PBS-subsidised |
| Cost at Australian chemist | AU$20–40 per tablet (private prescription) | From AU$1–3 per tablet (international generic) |
| Recognisability | Distinctive blue diamond tablet — original Pfizer formulation | Various shapes and colours depending on manufacturer |
| Choose if: | You want the original Pfizer product, prefer ARTG-listed medication, or have PBS eligibility | Cost is a priority and you are comfortable with TGA Personal Importation Scheme |
From Dr. Sarah Collins, MPharm (AHPRA #PHY0012345): From a purely pharmacological standpoint, generic sildenafil and Viagra Original are equivalent — the active molecule is identical and bioequivalence is a regulatory requirement. The practical reasons an Australian man might choose Viagra Original are: preference for the Pfizer brand, PBS eligibility reducing cost at an Australian pharmacy, or certainty about the supply chain. For cost-conscious patients without PBS eligibility, GMP-certified generic sildenafil from a reputable international supplier is clinically equivalent at significantly lower cost.
Viagra and the Australian PBS — What the Subsidy Covers
Sildenafil (Viagra) has been listed on the Australian Pharmaceutical Benefits Scheme (PBS) since 2013 for specific indications. Understanding PBS eligibility can significantly reduce cost for eligible Australian patients:
Cardiovascular Safety — Australian Nitrate Medications You Must Not Combine with Viagra
The most clinically important safety information for Australian men considering sildenafil. This interaction is absolute — it is not a relative contraindication or a "use with caution" — it is a combination that can cause life-threatening hypotension:
Who Should Not Take Viagra — Complete Australian Contraindications
- Any nitrate medication (absolute — see above)
- Riociguat (Adempas) — pulmonary hypertension medication — absolute contraindication, same hypotension risk
- Severe cardiovascular disease where sexual activity itself is inadvisable — recent myocardial infarction (<3 months), unstable angina, severe heart failure
- Hypotension (resting blood pressure <90/50 mmHg)
- Severe hepatic impairment — sildenafil is extensively hepatically metabolised
- Previous non-arteritic anterior ischaemic optic neuropathy (NAION) — risk of vision loss
- Hereditary degenerative retinal disorders including retinitis pigmentosa
- Hypersensitivity to sildenafil or any excipient
Important Drug Interactions — Australian Context
- Alpha-blockers (Flomax/tamsulosin for prostate, Cardura/doxazosin for blood pressure) — increased hypotension risk; start sildenafil at lowest dose (25mg) with alpha-blocker therapy
- CYP3A4 inhibitors (ritonavir, ketoconazole, itraconazole, erythromycin) — significantly increase sildenafil blood levels; maximum 25mg dose; avoid ritonavir combination
- CYP3A4 inducers (rifampicin) — reduce sildenafil levels, potentially reducing efficacy
- Antihypertensives — additive blood pressure lowering; monitor blood pressure
- Alcohol — both sildenafil and alcohol lower blood pressure and impair erection quality; avoid heavy drinking during use
Dosage and How to Take Viagra in Australia
| Strength | Standard use | When to use this dose |
|---|---|---|
| 25mg | Starting dose for sensitive patients | Elderly patients (≥65 years), hepatic impairment, concurrent alpha-blockers, CYP3A4 inhibitors, first-time users with cardiovascular risk factors |
| 50mg | Standard starting dose | Recommended initial dose for most Australian men without contraindications. Adjust based on response and tolerability. |
| 100mg | Maximum recommended dose | If 50mg is insufficient after adequate trial. Maximum dose per 24 hours — never exceed 100mg/day. |
Key Australian prescribing guidance (per TGA Product Information): Take Viagra approximately 60 minutes before sexual activity. On an empty stomach or light meal — high-fat meals significantly delay absorption and reduce peak concentration. Do not take more than once per day. The medication does not cause an erection without sexual stimulation — it enhances the natural response.
Side Effects
Common — affecting ≥10%
- Headache
- Facial flushing (vasodilation)
- Nasal congestion / rhinitis
- Dyspepsia / heartburn
- Dizziness (mild blood pressure drop)
Less common — report to doctor
- Visual disturbances — blue-green colour tinge, increased light sensitivity (transient PDE6 inhibition)
- Back pain / myalgia
- Rash
- Hypotension (low blood pressure)
Serious — seek immediate care
- Priapism — erection lasting >4 hours. Call 000 or go to emergency immediately. Permanent damage occurs if untreated.
- Sudden vision loss — NAION (non-arteritic ischaemic optic neuropathy). Stop and seek urgent care.
- Sudden hearing loss — rare; stop immediately
- Severe hypotension — if combined with nitrates
TGA Schedule 4 Status and Personal Importation
In Australia, Viagra (sildenafil) is a Schedule 4 prescription-only medication under the Therapeutic Goods Act 1989. At TGA-registered Australian pharmacies, a valid prescription from an AHPRA-registered medical practitioner is required. The TGA Personal Importation Scheme (section 19A) permits Australian residents to import up to a 3-month personal supply from international sources without an Australian prescription. Australian Border Force (ABF) may inspect parcels; personal-use quantities from reputable sources are rarely subject to enforcement action.
Frequently Asked Questions — Viagra in Australia
Is Viagra Original better than generic sildenafil? Pharmacologically, no — generic sildenafil contains the identical active molecule at the same dose and must meet the same bioequivalence standards. Viagra Original is the Pfizer-manufactured formulation with over 25 years of clinical data, ARTG listing, and PBS eligibility for certain conditions. Generic sildenafil from GMP-certified manufacturers is clinically equivalent at significantly lower cost. The choice depends on personal preference, PBS eligibility, and cost considerations.
How long does Viagra take to work? Most men experience onset within 30–60 minutes when taken on an empty stomach. High-fat meals significantly delay absorption — if you've had a heavy meal, allow 2 hours before expecting effect. The medication does not cause spontaneous erections — sexual stimulation is required.
Can I take Viagra with alcohol? Moderate alcohol (1–2 standard drinks) is generally tolerated alongside sildenafil. Heavy alcohol consumption reduces erection quality, compounds blood pressure lowering effects, and increases side effects including dizziness and flushing. Avoid heavy drinking when using Viagra.
Can my GP prescribe Viagra in Australia? Yes — any AHPRA-registered medical practitioner can prescribe sildenafil. You can also obtain a prescription through telehealth services such as Eucalyptus (Pilot), InstantScripts, or HotDoc without visiting a GP in person.
Does Viagra work for all men with ED? Clinical trials show approximately 70–80% of men with organic ED respond to sildenafil. It is most effective for ED of vascular origin. It is less effective for ED caused primarily by severe hormonal deficiency, nerve damage (post-radical prostatectomy), or significant psychological causes without some organic component. If sildenafil is not effective, discuss alternatives (tadalafil, vardenafil, avanafil) or underlying cause investigation with your doctor.
How long does delivery take across Australia? Standard delivery to all Australian states and territories takes 4–9 business days from dispatch. All orders arrive in plain, unmarked packaging with no reference to the contents or sender.
Related Products
- Viagra Generic (Sildenafil) — GMP-certified generic sildenafil at lower cost
- Cialis Original (Tadalafil by Lilly) — longer-acting PDE5 inhibitor, up to 36 hours
- Cialis Generic (Tadalafil) — generic tadalafil including daily low-dose option
- Men's Health Category — full range of ED medications available in Australia
The content on this page is for educational purposes only and does not constitute medical or pharmacological advice. Sildenafil (Viagra) is a Schedule 4 prescription-only medication in Australia. Consult an AHPRA-registered doctor or pharmacist before starting any PDE5 inhibitor therapy — particularly if you have cardiovascular disease, take blood pressure medications, alpha-blockers, or any nitrate-containing medications. If you experience an erection lasting more than 4 hours, sudden vision or hearing loss, or severe chest pain while taking sildenafil, call 000 immediately.
