# Sildenafil — Research Liquid

> Reference entry for a short-acting PDE5 inhibitor — 30 mg/mL solution, 30 mL bottle

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/sildenafil-research/
- Brand: Peptide Medix EU
- Category: [Hormonal & PDE5 Compounds](https://peptidemedixeu.com/en/collections/hormonal-compounds/)
- from €46 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 30 mL · 30 mg/mL | €46 | SILDENAFIL-RESEARCH-30-ML-30-MG-ML |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **Product status:** Prescription-only medicine; reference listing supplied only against valid authorisation
- **Compound class:** Pyrazolo[4,3-d]pyrimidinone; selective PDE5 inhibitor — a small molecule, not a peptide
- **Molecular target:** Phosphodiesterase type 5 (PDE5A), with lower-affinity activity at PDE6 and PDE1
- **CAS number (free base):** 139755-83-2
- **Molecular formula (free base):** C22H30N6O4S
- **Molecular weight (free base):** 474.58 g/mol
- **Common salt form:** Sildenafil citrate — different CAS and formula weight from the free base
- **Presentation:** 30 mL oral solution at 30 mg/mL
- **Approved indications (regulatory fact):** Erectile dysfunction; pulmonary arterial hypertension at separately approved strengths
- **Mechanism:** Blocks cGMP hydrolysis, prolonging nitric-oxide-driven smooth-muscle relaxation
- **Reported pharmacokinetics:** Rapid oral absorption; hepatic metabolism principally by CYP3A4; terminal half-life reported around 3–4 hours
- **Known interaction class (regulatory fact):** Contraindicated with nitrates and nitric-oxide donors in approved labelling
- **Storage:** Controlled room temperature, tightly closed and protected from light; do not freeze
- **Intended use:** Reference listing — dispensed only under valid prescription or institutional authorisation

## Description

Sildenafil is a selective blocker of phosphodiesterase type 5 (PDE5). Chemically a pyrazolo[4,3-d]pyrimidinone, it emerged from a Pfizer research programme on angina at the start of the 1990s. It was later authorised under the name Viagra for erectile dysfunction, in 1998, and — at different strengths — under the name Revatio for pulmonary arterial hypertension. We cite these authorisations only as public regulatory facts; they are not a recommendation to use it.

Sildenafil may be supplied only on prescription. This page is part of an institutional and demonstration reference catalogue, and we release material solely against a valid prescription or an institution's documented authorisation. You will find no information on where else to obtain it, how to take it or what dose to use — neither here nor from our staff.

In its free-base form sildenafil is C22H30N6O4S, weighing 474.58 g/mol. Tablets on the market normally contain the citrate salt instead, which is registered under another CAS number and has a higher formula weight. The product described here is an oral solution: 30 mg per millilitre in a 30 mL bottle. Because it is among the most thoroughly understood probes of nitric oxide–cGMP signalling, laboratories also use sildenafil widely as a pharmacological tool in vascular, lung and heart research.

## Frequently asked questions

### Can it be obtained without a prescription?

No — sildenafil can only be supplied on prescription. This page belongs to an institutional and demonstration reference catalogue; we release the material exclusively against a valid prescription or an institution's documented authorisation and offer no route around that requirement.

### What separates sildenafil base from sildenafil citrate?

Sildenafil base (CAS 139755-83-2) weighs 474.58 g/mol. Commercial tablets usually contain sildenafil citrate, which has a CAS number of its own and a greater formula weight. Whenever a concentration is quoted, it should say which of the two forms it means.

### Why is one drug authorised for two such different conditions?

Both uses stem from one mechanism: blocking PDE5 extends cGMP signalling and relaxes smooth muscle, which matters in the penile blood vessels and in the pulmonary arteries. The two indications have separate marketing authorisations and different authorised strengths.

### Is dosing information provided?

No. How much to give, how to adjust it and how to administer it are questions for the prescriber and the authorised product information in each country. This page limits itself to chemistry, mechanism, regulatory status and storage, and our team gives no advice about use.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/sildenafil-research/