What Is Sildenafil? How It Works & What to Expect

Sildenafil is one of the most well-known medications for erectile dysfunction — it's the active ingredient behind the brand name Viagra®, and it's been helping men get and keep stronger erections for decades.

In this guide, we'll break down exactly what sildenafil is, how it works, the benefits it can bring (sexual and otherwise), and how BlueChew makes it available in a fast-acting sublingual tablet called SIL.

Key Takeaways

• Sildenafil is a PDE5 inhibitor that increases blood flow to the penis, supporting stronger, longer-lasting erections.
• It's the same active ingredient found in brand-name Viagra, with a safety and effectiveness track record spanning almost 30 years and success rates up to 80%.
• BlueChew offers sildenafil as SIL, a compounded sublingual tablet that may start working in as little as 15 minutes — no water or swallowing required.
• Beyond erections, ongoing research points to a range of other potential health benefits, from exercise capacity to mood and cardiovascular protection.
• Ready to see if SIL is right for you? Take the quiz.

What is Sildenafil?

Sildenafil is a prescription medication first made popular as the original erection-enhancing treatment, better known under the brand name Viagra. It belongs to a class of drugs called phosphodiesterase-5 (PDE5) inhibitors, and it works by increasing blood flow to the penis to support a firm, lasting erection.

BlueChew offers sildenafil as SIL — a convenient, compounded sublingual tablet prescribed for as-needed use. What makes SIL unique is that it's a compounded medication, which means it's custom-made in the dosage and form best suited to our patient's needs, rather than a one-size-fits-all pill.

Why a Sublingual Tablet Instead of a Pill?

Sublingual tablets have a few distinct advantages over traditional pills:

• Convenience — take it anywhere, let it dissolve under your tongue, and you're done. No water, no swallowing, no bad taste.
• Speed — research has shown sublingual medications like SIL may kick in faster than standard pills, with sublingual sildenafil potentially taking effect in as little as 15 minutes.
• Discretion — a small, easy-to-carry tablet that doesn't look like a prescription bottle.

How Does Sildenafil Work?

SIL, containing the active ingredient sildenafil, is a type of medication known as a phosphodiesterase-5 inhibitor or PDE5i for short.

It works by blocking the action of an enzyme called phosphodiesterase-5 (PDE5). This enzyme typically breaks down a molecule called cyclic guanosine monophosphate (cGMP), which is crucial for releasing nitric oxide (NO). When NO is released, it helps to dilate blood vessels.

By stopping PDE5 from breaking down cGMP, sildenafil increases NO levels. This uptick in NO relaxes the smooth muscles in blood vessels, allowing more blood to flow to the penis.

As blood flow increases, the tissue becomes engorged, making it easier to achieve and maintain a hard, long-lasting erection during sexual stimulation.

What are the Sexual Health Benefits?

Thanks to its blood-flow-enhancing properties, sildenafil can help you achieve and maintain harder erections, with patients reporting significant improvements in erection quality and erectile function. The rate of improvement has also been found to be higher in younger patients, so gains may be faster and more pronounced if you're under 60.

Beyond erection quality, sildenafil has been linked to increased intercourse success rates, sexual satisfaction, orgasms, and even improved quality of life — benefits reported by both patients and their partners. These improvements in sexual performance can also boost confidence and self-esteem in and out of the bedroom, and have been linked to stronger sexual and social relationships.

What are the Potential Health Benefits of Sildenafil?

Sildenafil gained FDA approval over thirty years ago for erectile dysfunction, but research has since found it may support a variety of other health parameters — though it's important to note these uses are not FDA-approved. Possible additional benefits include:

• Reduces inflammation and damage from oxidative stress
• Improves skeletal muscle oxygenation during exercise and exercise capacity
• Increases muscle protein synthesis and reduces muscle fatigue
• Increases testosterone levels
• Enhances mood
• Reduces heart rate during exercise
• Protects nerves, prevents their degeneration, and promotes their growth
• Improves kidney function and protects kidneys from damage
• Reduces chronic pain and neuropathic pain
• Prevents gastric ulcers and cardiac remodeling
• Protects the heart from damage
• Reduces risk of heart attack, stroke, and risk of death due to such events
• Improves urinary tract function
• Reduces blood pressure
• Protects against harmful effects of stress
• Improves cognitive function
• Improves recovery from jet lag

But did you know that sildenafil, in addition to its better-known health-boosting properties, may also help treat cancer, reduce the risk of Alzheimer’s disease, and prevent altitude sickness?

Interested in learning more about the wide range of potential health benefits of taking sildenafil? Check out our blog post here.

How Often Can I Take SIL?

SIL is prescribed for on-demand use, so it's best taken before an evening out or date night when the opportunity for intimacy might arise. Your BlueChew provider will give you specific instructions, but generally, SIL is taken about 15 minutes before sexual activity. Avoid taking it more often than your provider recommends.

How long does SIL last?

Once taken, SIL can produce erections for anywhere between 4 to 6 hours. It's best taken 15 minutes to 1 hour before an expected intimate moment, and it will only cause an erection with sexual stimulation.

A few tips for best results:

• Take SIL on a relatively empty stomach — high-fat meals may slow absorption.
• Skip the cocktail — alcohol can reduce the medication's effectiveness.
• Avoid grapefruit juice, which may alter how sildenafil works in your body.

Because SIL requires precise timing and has a shorter duration of action than some other options, it may not be the right fit for everyone.

If you're weighing your choices, our side-by-side comparison of BlueChew's medications can help you decide, or you can talk it through directly with a BlueChew provider.

What are the Potential Side Effects of Sildenafil (SIL)?

While SIL is typically well-tolerated, like all prescription medications, it carries a risk of side effects. Sildenafil has a solid safety and effectiveness track record spanning almost 30 years, with success rates up to 80%, but it's still worth knowing what to look out for.

Common side effects:

• Skin flushing
• Headache
• Indigestion
• Light nasal congestion
• Muscle pain

Less common but more serious: a prolonged erection lasting more than 4 hours, low blood pressure, sudden vision loss, irregular heartbeat, or sudden decrease in hearing. If you experience any of these, contact your doctor or a member of the BlueChew medical team right away. Although rare, allergic reactions are also possible — seek emergency care immediately if symptoms are severe. For the full list, see our safety information page.

How To Get Erectile Dysfunction Medications from BlueChew

Ready to see if SIL is the right fit? BlueChew makes it simple: select a plan, complete an online intake, and you're done. A licensed provider reviews your information and, if appropriate, prescribes your plan, which ships directly to your door — no in-person appointments or extra support charges.

Plans start as low as $25/month, with no commitment — cancel or switch anytime. Explore all plan options →

FAQ

Is sildenafil the same as Viagra?

Both SIL and Viagra contain the active ingredient sildenafil. SIL is a compounded medication available in sublingual form; compounded medications are custom-made by state-licensed pharmacies and are not FDA-approved, but contain the same active ingredient as their brand-name counterparts.

Why use a sublingual tablet instead of a pill?

Sublingual SIL offers unmatched convenience — no water needed, easy to take anywhere, and shown to work faster than traditional pills.

What are the sexual health benefits of sildenafil?

SIL enhances blood flow to the penis for harder, longer-lasting erections, and has been linked to improved sexual satisfaction and confidence for both users and partners. Note: SIL does not protect against sexually transmitted diseases, so continue practicing safe sex.

What are the potential health benefits of sildenafil?

Beyond erection enhancement, research (though not FDA-approved for these uses) suggests sildenafil may reduce inflammation, improve exercise capacity and muscle oxygenation, enhance mood and cognitive function, lower blood pressure, protect nerves, and reduce cardiovascular risk. It's also used to treat pulmonary arterial hypertension.

See our full health benefits post for more.

How long does SIL make you last?

Effects typically last 4 to 6 hours, best taken 15 minutes to 1 hour before intimacy. Avoid high-fat meals, alcohol, and grapefruit juice for best results.

How do I get a prescription for SIL through BlueChew?

Select your plan, create an account, and complete a medical intake form. A licensed provider reviews your history and prescribes SIL if appropriate.

What are the potential side effects of sildenafil?

Possible side effects include severe headache, indigestion, blurred vision, prolonged erection, hearing loss, low blood pressure (especially combined with other blood-pressure-lowering drugs), chest pain, and irregular heartbeat. Contact your doctor immediately if you experience any of these. Those with certain conditions, like sickle cell anemia or pulmonary veno-occlusive disease, should discuss suitability with a provider, and any current medications should be disclosed to avoid interactions.

This article is provided for informational purposes only and does not constitute medical advice. The information presented is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider to discuss the risks, benefits, and appropriateness of any treatment.

BlueChew offers access to healthcare providers who may prescribe compounded medications for the treatment of erectile dysfunction.

The featured products include compounded medications that have not been approved by the FDA. Compounded medications may be prescribed under federal law but are not the same as, nor are they generic versions of, any FDA-approved medication. The FDA does not review compounded medications for safety, effectiveness, or manufacturing quality of compounded products. A prescription will only be written if deemed appropriate after the digital consultation by the licensed medical provider. Individual results may vary.

BlueChew is not a compounding pharmacy but a telemedicine service that links patients to licensed medical providers.