2D structure · PubChem CID 135413523Sildenafil citrate

ZionovaSexual healthSKU Zionova Viagra

Zionova Viagra

Sildenafil citrate · Oral tablet

5.0 from 31 reviews

$132CAD

In stock, ships from Vancouver

Strength50 mg per tablet

Pack50 tablets

Total per order2,500 mg

Half-life≈ 4 hours

Add $168 more for free Xpresspost.

Delivery guaranteeLost or seized: reshipped free
Tracking in 72 hPacked in Vancouver
Interace-TransferFrom any Canadian bank
Plain packagingNo product names outside

Overview

Viagra is sildenafil citrate, the first PDE5 inhibitor approved for erectile dysfunction.

How it works

It blocks PDE5 so that blood flow to the penis increases after sexual stimulation.

Chemistry

From PubChem, the US National Library of Medicine’s chemistry database.

Sildenafil citrate

Formula: C₂₈H₃₈N₆O₁₁S
Molecular weight: 666.7 g/mol
CAS: 171599-83-0
PubChem CID: 135413523 ↗

Clinical reference

The label starting amount is 50 mg about an hour before sex, adjusted between 25 and 100 mg, at most once a day.

Label and guideline amounts are shown for reference only. They are not a recommendation, and we never give cycle or performance amounts. Any use belongs under a doctor’s care, with bloodwork.

Measuring calculator

Converts an amount you enter into what to measure. It does not suggest an amount.

Your amountEnter an amount to see the conversion.

Strength used: 50 mg per tablet · pack: 50 tablets

Combinations and interactions

Prescribed or used alongside

Not combined with other PDE5 inhibitors unless a doctor directs it.

Drug interactions

Nitrates and poppers: never combine; blood pressure can crash.
Alpha blockers: extra blood pressure lowering.
CYP3A4 inhibitors: raise sildenafil levels.

Risks and bloodwork

Check the strength

Compare the tablet strength with the 100 mg label maximum.

Headache, flushing, stuffy nose

Common.

Blue-tinted vision

Temporary colour changes are possible.

Priapism

Over four hours is an emergency.

Bloodwork doctors check

Blood pressure
A heart check if you have heart disease or chest pain

Not for

People under 18, anyone pregnant or breastfeeding, and anyone with liver disease, heart disease, uncontrolled blood pressure or a hormone-sensitive cancer, unless a doctor directs otherwise.

Canadian legal status

In Canada this is a prescription drug under the Food and Drugs Act. Using it under a doctor’s care, with bloodwork, is how it is meant to be used. This is general information, not legal advice.

References

Oral sildenafil in the treatment of erectile dysfunction. Sildenafil Study GroupGoldstein I et al. · N Engl J Med, 1998 · PMID 9580646
Phosphodiesterase Type 5 Inhibitors and Oral Nitrates in Male Patients with Ischemic Heart DiseaseMorrisette MJ, Dunn SP · Curr Cardiol Rep, 2023 · PMID 37074567

Reviews

5.031 reviews from customers

Reviews are published after a quick check. Only customers who bought this product can review it.

Paul G.Verified buyerOct 15, 2025

Rated without a written review.