Sildenafil, sold under the brand name Viagra, is a prescription medication for erectile dysfunction and the first drug of its class to be approved in the United States. It is taken before sexual activity, it depends on sexual stimulation to do anything at all, and it must not be combined with nitrate medications. Most of what follows is about those points and about where a compounding pharmacy does and does not fit.
What is sildenafil and how does it work?
Sildenafil is a phosphodiesterase type 5 inhibitor, usually shortened to PDE5 inhibitor. Tadalafil, vardenafil, and avanafil belong to the same class.
An erection depends on blood flow. Sexual stimulation triggers the release of nitric oxide in the tissue of the penis, which raises levels of a signalling molecule called cyclic GMP. Cyclic GMP relaxes the smooth muscle in the blood vessel walls, letting more blood flow in. An enzyme called PDE5 breaks cyclic GMP down again. Sildenafil blocks that enzyme, so cyclic GMP persists longer and the relaxation is sustained.
The practical consequence is worth stating clearly, because it is widely misunderstood: sildenafil does not create arousal. It acts on a pathway that sexual stimulation starts. Without stimulation, the drug has little to do.
Where did sildenafil come from?
Sildenafil was developed by Pfizer in the early 1990s as a candidate for angina and high blood pressure. It performed unremarkably for those, but trial participants reported an unexpected effect, and the programme was redirected. The FDA approved it for erectile dysfunction in 1998, and it became one of the most recognised prescription medicines in the world.
The same molecule was later approved separately, at different dosing, for pulmonary arterial hypertension, where relaxing blood vessels in the lungs is the point.
How is sildenafil taken?
Follow your prescriber's directions rather than a general rule. Typically it is taken about 30 to 60 minutes before sexual activity, with effects lasting up to around four hours. Common starting doses are in the 25 to 100 mg range, and prescribers adjust based on response and other medications.
A heavy or high-fat meal can slow absorption and delay onset. It is not taken more than once a day. If nothing happens the first time, that is worth reporting to your prescriber rather than increasing the dose yourself; dose, timing, and expectations around stimulation are all common explanations.
Prescribers commonly ask patients to try a PDE5 inhibitor on several separate occasions before drawing a conclusion, because timing, food, alcohol, anxiety and the amount of stimulation all vary between attempts. One disappointing evening is not usually enough information to change a prescription.
Dose, dose form and whether any of this is appropriate for you are the prescriber's decisions, not the pharmacy's. Bayview Pharmacy dispenses what is written on a prescription for a named patient and does not run consultations or recommend a dose.
How do sildenafil, tadalafil and vardenafil differ?
All three are PDE5 inhibitors and all three depend on sexual stimulation. What separates them in practice is how long the effect lasts and which dose forms exist. The table below covers the manufactured tablets alongside the compounded preparations a prescriber may specify when a manufactured form does not fit.
| Preparation | Route | Typical onset | Status |
|---|---|---|---|
| Sildenafil tablet | Oral | 30 to 60 min | FDA-approved |
| Tadalafil tablet | Oral | 30 to 120 min | FDA-approved |
| Vardenafil tablet | Oral | 30 to 60 min | FDA-approved |
| Sildenafil dissolve tablet | Oral, dissolved | Set by prescriber | Compounded, not FDA-approved |
| Alprostadil combination injection | Intracavernosal | Set by prescriber | Compounded, not FDA-approved |
| Apomorphine troche | Sublingual | Set by prescriber | Compounded, off-label |
Tadalafil is the outlier on duration: its window is measured in hours to more than a day rather than a single evening, which is why it is sometimes prescribed on a daily schedule instead of before activity. Vardenafil sits closer to sildenafil in timing. Avanafil is manufactured but is not part of what Bayview prepares.
Who should not take sildenafil?
Nitrates are the critical one. Sildenafil must not be taken with nitrate medications such as nitroglycerin, isosorbide mononitrate or dinitrate, including sprays and patches, or with recreational nitrites, sometimes called poppers. The combination can cause a severe and dangerous drop in blood pressure. If you carry nitroglycerin for chest pain, tell your prescriber before starting a PDE5 inhibitor.
Alpha-blockers used for blood pressure or prostate symptoms can also lower blood pressure in combination, so timing and dose need to be considered. Tell your prescriber about heart disease, a recent heart attack or stroke, low blood pressure, liver or kidney problems, retinitis pigmentosa, and every medication you take.
Sexual activity itself places demand on the heart. If you have been advised to limit exertion, that conversation belongs with your prescriber before any PDE5 inhibitor is started, not after.
What side effects should you watch for?
Common side effects include headache, facial flushing, indigestion, nasal congestion, dizziness, and changes in colour vision or light sensitivity. Most are dose-related and are the reason prescribers often start low.
Seek emergency care for an erection lasting more than four hours, which can cause permanent damage, and for sudden loss of vision or hearing, chest pain, or fainting. A prolonged erection is a urological emergency and is not something to wait out.
Does alcohol or grapefruit change how sildenafil behaves?
Alcohol can contribute to erectile difficulty on its own, and it lowers blood pressure, so it adds to the same effect the drug has. A large amount before sexual activity works against the reason the tablet was prescribed. How much, if any, is reasonable for you is a question for your prescriber.
Grapefruit and grapefruit juice inhibit the CYP3A4 enzyme that clears sildenafil from the body, which can raise blood levels and make side effects such as flushing and headache more noticeable. The interaction is documented on the manufactured product labeling. If grapefruit is a regular part of your diet, mention it rather than assuming it is irrelevant.
Is erectile dysfunction worth investigating on its own?
Often, yes. ED can be an early sign of cardiovascular disease, diabetes, or hormonal problems, and it also has psychological and medication-related causes. Treating the symptom without asking why it appeared can mean missing something that matters more.
Low serum testosterone is one of the causes a prescriber may look for, and it is evaluated with bloodwork rather than assumed; our overview of testosterone replacement therapy covers how that workup usually runs.
Herbal and over-the-counter products are a common first stop and are worth understanding before you spend money on them. We looked at how horny goat weed compares with sildenafil in a separate article, including what the published evidence on the herb actually consists of.
What are the options if a sildenafil tablet is not the right fit?
Some patients cannot swallow tablets, cannot tolerate the oral route, or have a prescriber who wants a different dose form for reasons specific to them. In those situations a prescriber may write for sildenafil oral dissolve tablets, which are placed in the mouth and allowed to disintegrate rather than swallowed whole.
Dissolve tablets and troches sit in a family of dose forms that behave differently from swallowed tablets; our article on sublingual and dissolve dose forms explains what changes and what does not.
Where oral therapy is not an option at all, prescribers sometimes turn to injectable preparations such as alprostadil, papaverine and phentolamine injection, which is administered into the penis and is prepared only on a prescription written for an individual patient. These are compounded preparations and are not FDA-approved.
Another preparation a prescriber may specify is apomorphine sublingual troches. Apomorphine acts on dopamine pathways rather than on PDE5, and it is not an FDA-approved product for erectile dysfunction in the United States, so any such prescription is an off-label use and the published evidence is limited.
None of these are interchangeable and none should be combined with each other unless a prescriber has said so in writing. Stacking an oral PDE5 inhibitor with an injectable preparation raises the risk of a prolonged erection, which is the complication that sends people to an emergency department.
Why would sildenafil be compounded at all?
Sildenafil tablets are commercially manufactured and widely available, and where a manufactured product fits the prescription, that is what should be dispensed. Compounding is not a route to a cheaper version of an available product and we do not present it as one.
There is a legal reason as well as an ethical one. Under section 503A of the Federal Food, Drug, and Cosmetic Act, a compounding pharmacy may not prepare a drug product that is essentially a copy of a commercially available product. A compounded sildenafil preparation is dispensed when the prescriber documents a specific clinical need the manufactured tablet does not meet.
In practice that means a dosage form that does not exist commercially, such as an oral dissolve tablet, or a strength or combination a prescriber specifies for an individual patient. Those preparations are compounded, are not FDA-approved, and require a prescription. You can browse the wider set of sexual health and urology preparations to see what that category covers.
What does a compounded sildenafil preparation cost?
Compounded sildenafil prepared by our pharmacy starts at $47, with the final price depending on the strength, the dose form and the quantity your prescriber writes. Oral dissolve tablets are priced separately and start higher.
Compounded preparations are not billed through insurance. Because each one is made to a specific prescription rather than assigned a national drug code, they are paid for directly, and we quote the price before anything is prepared. Questions about pricing, shipping and the states where Bayview is licensed are answered in our frequently asked questions.
What Bayview compounds for erectile dysfunction
On a prescriber's order, Bayview Pharmacy prepares the sildenafil strengths and dose forms listed on our formulation page, along with tadalafil and vardenafil in oral and dissolve forms, intracavernosal injections combining alprostadil, papaverine and phentolamine, urethral gels, and apomorphine sublingual troches. Strengths and combinations are set by the prescription, not by a menu.
These are non-sterile and sterile preparations made in our compounding lab in Warwick, Rhode Island, using USP 795 non-sterile compounding standards and, for injectables, our USP 797 sterile lab. Our erectile dysfunction compounding service describes how prescribers work with us.
If you want to see the wider range first, the searchable catalog of compounded medications lists every preparation we can make, organised by category.
Talk to your prescriber
If erections have changed, start with a clinician who can look at the whole picture: cardiovascular risk, medications you already take, hormones, sleep, and mood. That conversation decides whether a PDE5 inhibitor belongs in the plan, which one, and at what dose.
If a prescription is written for a preparation we make, it can be sent to Bayview Pharmacy, 3844 Post Rd, Warwick, RI 02886, by e-prescribing or by fax to 401-284-4506. We will confirm the price and the details with you before we prepare anything.
Frequently asked questions
How fast does sildenafil work?
Usually within 30 to 60 minutes, with effects lasting about 4 to 6 hours. Taking it on an emptier stomach helps it absorb faster, since a heavy or fatty meal can delay onset. Sexual stimulation is still needed; the medication enables the response rather than causing an erection on its own.
How does compounded sildenafil compare to the FDA-approved tablet?
Viagra® and its generics are FDA-approved conventional tablets. Bayview dispenses those manufactured tablets, and separately compounds sildenafil as cheek-and-gum troches and under-the-tongue rapid dissolve tablets in the strength your provider specifies. Compounded preparations are not FDA-approved and have not been evaluated by FDA for safety or effectiveness. Your prescriber decides which form is appropriate for you.
What forms can I get?
Swallowed tablets, cheek-and-gum troches, and under-the-tongue rapid dissolve tablets. The troche and rapid dissolve forms are taken without water and suit men who dislike swallowing pills or want a more discreet option. Your provider picks the form and strength that fit you.
Who should not take sildenafil?
Anyone taking nitrates or riociguat, or allergic to sildenafil. Combining with nitrates can dangerously lower blood pressure. Tell your provider about heart conditions and other medicines.
Are there side effects?
Most side effects are mild and short-lived: headache, facial flushing, a stuffy nose, or mild indigestion. Seek care right away for an erection lasting more than 4 hours, or sudden changes in vision or hearing. Never combine sildenafil with nitrates; the combination can drop blood pressure dangerously.
How do I get it from Bayview?
Your provider sends a prescription, we compound your order to their exact strength and form, and we ship it discreetly to your door. Bayview fills for patients in RI, MA, CT, NY, NJ, NH, FL, and ME. If you do not have a prescriber yet, your primary care provider or a telehealth visit is a good starting point.
Does food affect how it works?
It can. Sildenafil generally absorbs faster on an emptier stomach, and a heavy or high-fat meal can delay how quickly it takes effect. Take it as your prescriber directs, and tell them if the timing has been inconsistent for you.
What if it does not work the first time?
Do not take an extra dose or change your timing on your own. Response can depend on dose, timing, food, and individual factors, and sexual stimulation is still needed for the medication to work. Contact your prescriber, who can review whether a different strength or form is appropriate.
How is this different from the dissolve form?
The active ingredient is the same sildenafil; only the dosage form differs. These tablets are swallowed with water, while our rapid dissolve tablets and troches dissolve in the mouth without water. Your provider chooses the form and strength that fit you.
What are oral dissolve tablets?
Oral dissolve tablets are compounded tablets designed to dissolve in the mouth, usually on or under the tongue. They may be useful for patients who require faster onset, have difficulty swallowing capsules or prefer a dosage form that does not require water.
How do oral rapid dissolve tablets work?
The tablet dissolves in the mouth and releases the medication. Depending on the medication and how it is absorbed, this dosage form may allow for a faster onset compared with swallowing a traditional tablet.
Why is tadalafil called the weekend pill?
One dose can last up to 36 hours, so intimacy does not have to be timed around a pill; a Friday evening dose can still be working Sunday morning. That long window is tadalafil's signature difference from sildenafil and vardenafil. It still requires sexual stimulation, and the duration is a window of readiness, not a continuous effect.
How is it different from sildenafil?
They work the same way, blocking the PDE5 enzyme, with similar onset and duration. The practical difference is individual response: some men get better results or fewer side effects from one than the other, so vardenafil is a common next step when sildenafil has not been the right fit.
Why are ED injections compounded?
ED injections are often compounded because prescribers may need a specific combination, strength, or dose that is not available as a standard manufactured product. Compounding allows the medication to be prepared according to the prescriber’s instructions and adjusted to the patient’s individual response.
What is priapism and what should I do if it happens?
Priapism is an erection that lasts too long and does not go away normally. An erection lasting 4 hours or longer is a medical emergency because it can cause permanent injury if not treated promptly. Follow your prescriber’s emergency instructions and seek urgent medical care if this occurs.
What Bayview compounds for this
Important: Compounded medications are prepared to a prescriber's order for an individual patient. They are not FDA-approved, and the FDA has not evaluated them for safety, effectiveness, or manufacturing quality. This article is educational and is not a substitute for advice from your prescriber or pharmacist.
This preparation contains a controlled substance. Controlled-substance prescriptions carry refill limits, must be e-prescribed, and can only be shipped to states where Bayview holds the required licensure.
Uses discussed here may be off-label, meaning they are not part of any FDA-approved labeling. Off-label use is a decision for you and your prescriber, based on the available evidence.
Veterinary preparations are compounded to a veterinarian's order for a specific animal and are not FDA-approved animal drugs. Never give a compounded human medication to an animal without veterinary direction.
Compounded prescriptions are paid for directly rather than billed through insurance. Most are HSA/FSA-eligible, and many patients submit the receipt to their plan for possible reimbursement. Pricing depends on the strength, dose form and quantity your prescriber orders. Read more about cost and insurance.
Compounded sildenafil starts at $47, with the final price set by the strength, dose form and quantity on the prescription. Oral dissolve tablets are priced separately and start higher. Compounded preparations are not billed through insurance: each is made to an individual prescription rather than carrying a national drug code, so they are paid for directly and we quote the price before anything is prepared.
Bayview Pharmacy is an NABP-accredited compounding pharmacy in Warwick, Rhode Island, licensed to fill and ship compounded prescriptions for patients in Rhode Island, Massachusetts, Connecticut, New Jersey, New Hampshire, Florida, New York and Maine. Controlled substances are not shipped to New York addresses. See where we ship and how to get started.
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