Zenegra is a tablet form of sildenafil citrate, a phosphodiesterase‑5 (PDE5) inhibitor used to treat erectile dysfunction (ED), typically supplied in 100mg tablets and approved by the Australian Therapeutic Goods Administration (TGA).
Sildenafil blocks the enzyme PDE5, which normally breaks down cyclic guanosine monophosphate (cGMP). By preserving cGMP, blood vessels in the penis relax, allowing increased blood flow during sexual stimulation. The effect starts within 30‑60minutes and peaks around 90minutes.
The most common alternatives belong to the same drug class. Below are concise definitions of each, marked up for semantic clarity.
Viagra is a brand‑name formulation of sildenafil citrate, originally launched by Pfizer in 1998 and widely recognized as the first oral ED treatment.
Cialis contains tadalafil, a longer‑acting PDE5 inhibitor that can provide up to 36hours of erectile support, earning the nickname "the weekend pill".
Levitra is a vardenafil‑based medication introduced in 2003, offering a rapid onset (as quick as 15minutes) and a duration of about 4‑5hours.
Stendra (avanafil) is the newest FDA‑approved PDE5 inhibitor, known for an ultra‑fast onset (around 10minutes) and a moderate duration of 6‑12hours.
L‑arginine is an amino‑acid supplement that boosts nitric oxide production, indirectly supporting penile blood flow but with modest efficacy for most men.
Yohimbine is an alkaloid extracted from the bark of African Yohimbe trees, used in low doses as an herbal aid for ED, though it can cause anxiety and blood‑pressure spikes.
PDE5 inhibitors represent a drug class that includes sildenafil, tadalafil, vardenafil and avanafil; they share a common mechanism but differ in pharmacokinetics and side‑effect profiles.
| Medication | Active Ingredient | Typical Dose | Onset | Duration | Approx. Cost (AU$) |
|---|---|---|---|---|---|
| Zenegra | Sildenafil citrate | 50‑100mg | 30‑60min | 4‑6hrs | ≈30 per pack |
| Viagra | Sildenafil citrate | 50‑100mg | 30‑60min | 4‑6hrs | ≈45 per pack |
| Cialis | Tadalafil | 10‑20mg | 15‑30min | Up to 36hrs | ≈55 per pack |
| Levitra | Vardenafil | 10‑20mg | 15‑30min | 4‑5hrs | ≈50 per pack |
| Stendra | Avanafil | 50‑200mg | ≈10min | 6‑12hrs | ≈70 per pack |
| L‑arginine (supplement) | Amino‑acid | 2‑5g daily | Varies | Continuous | ≈20 per month |
| Yohimbine (herbal) | Alkaloid | 5‑10mg as needed | 30‑60min | 2‑4hrs | ≈15 per month |
Clinical trials consistently show that sildenafil‑based drugs (Zenegra, Viagra) achieve successful erections in about 60‑70% of men with mild‑to‑moderate ED. Tadalafil (Cialis) edges slightly higher (≈75%) for men who need spontaneity because the long window reduces timing anxiety. Vardenafil (Levitra) and avanafil (Stendra) sit in the same 65‑70% range but shine for men who want a quicker onset.
Natural options such as L‑arginine or yohimbine often report modest improvements (10‑20% response) in studies with small sample sizes. They may be useful as adjuncts for men with mild symptoms or those who cannot tolerate PDE5 inhibitors due to cardiovascular concerns.
All PDE5 inhibitors share a core side‑effect profile: headache, facial flushing, nasal congestion, dyspepsia, and rare visual disturbances. The risk of priapism (prolonged erection) is <1% across the class.
Key contraindications include:
Herbal supplements have their own red flags. Yohimbine can raise heart rate and blood pressure, making it unsuitable for men with anxiety disorders or hypertension. L‑arginine is generally safe but may interact with certain blood‑pressure medications.
Zenegra is sold by accredited online pharmacies and often costs 30‑35AU$ for a 4‑week supply of 100mg tablets. Viagra, being a brand under stricter patent control, sits closer to 45‑60AU$. Cialis and Stendra are the priciest, reflecting longer half‑lives and newer patents.
All prescription‑only PDE5 inhibitors require a valid doctor’s script in Australia. However, many telehealth services now offer rapid assessment, and some online pharmacies can dispense Zenegra after a virtual consult. Supplements like L‑arginine and yohimbine are over‑the‑counter but lack the same regulatory oversight.
Follow this quick decision flow:
Remember that lifestyle changes - weight loss, regular exercise, quitting smoking - boost the success of any medication.
Understanding the broader context helps you stay informed. Key related topics include:
Future articles could dive deeper into "How to Talk to Your Doctor About ED" or "Evaluating Shockwave Therapy for Refractory ED" - both natural progressions from what we covered here.
Clinical data shows that both contain the same active ingredient (sildenafil) and deliver comparable erection rates when taken at the same dose. The main differences lie in price and brand perception.
No. Combining any PDE5 inhibitor with nitrates can cause a dangerous drop in blood pressure. Talk to your doctor for safe alternatives.
Typical sexual activity can be supported for 4‑6hours after ingestion. Effects begin within 30‑60minutes.
L‑arginine may help men with mild‑to‑moderate ED, but studies show limited benefit for severe cases. It’s best used as a supplement alongside, not instead of, prescription medication.
Seek emergency medical care immediately. Prolonged erections (priapism) can damage penile tissue if not treated promptly.
1 Comments
Joshua Agabu September 24, 2025
Zenegra is basically the generic version of Viagra, so it gives you the same punch without the brand premium.