Sildenafil: evidence, safety, regulatory status and cost

Sildenafil citrate (Viagra) — PDE5 inhibitor.

What Sildenafil is

Sildenafil is a PDE5 inhibitor, FDA-approved for erectile dysfunction and (as Revatio) for pulmonary arterial hypertension. It has a shorter half-life than tadalafil — roughly 4 hours — giving an effective window of about 4 to 6 hours, and it works best taken on an empty stomach. It is available as a low-cost generic.

Regulatory status

Sildenafil is FDA-approved and available as an inexpensive generic. As with tadalafil, there is rarely a good reason to pay more for a compounded troche, a 'proprietary blend' or a stacked combination product. Those are not FDA-approved and have no demonstrated advantage.

How Sildenafil differs from the alternatives

What makes sildenafil different from tadalafil. Sildenafil is the shorter-acting drug: a half-life of about 4 hours and an effective window of 4-6 hours, against tadalafil's 36.

That is not automatically worse, and for some men it is better. (1) Shorter exposure, shorter side effects. If you get headache or flushing, they clear faster. (2) It is the oldest and most-studied PDE5 inhibitor, with the longest post-marketing safety record of any drug in this class. (3) It is usually the cheapest generic.

The trade-offs are real. Food matters: a high-fat meal delays and blunts absorption, so sildenafil is best taken on a relatively empty stomach — a genuine planning constraint that tadalafil does not impose. No daily option and no BPH indication: if you have prostate symptoms as well as ED, tadalafil treats both and sildenafil does not. And the characteristic visual side effect — a transient blue tinge to vision — is a sildenafil phenomenon, related to PDE6 cross-reactivity in the retina.

What the evidence shows

Extensively studied and clearly effective for erectile dysfunction across large randomised trials, with decades of post-marketing data. Along with tadalafil, this is among the best-evidenced treatments covered on this site.

Safety and side effects

Headache, flushing, dyspepsia, nasal congestion and visual disturbance (notably a transient blue tinge, which is a real and characteristic effect) are common. Never combine with nitrates. Use caution with alpha-blockers. A high-fat meal delays and blunts absorption. Seek emergency care for priapism or sudden vision or hearing loss.

Who is actually who: the entities in this transaction

The single biggest source of confusion in telehealth medicine is that people assume one company is doing all of it. Usually four or five separate entities are involved, with different regulators and different duties to you.

Eligibility, and who is likely to be declined

A licensed clinician decides whether treatment is appropriate. No website can promise you eligibility, and one that implies it should worry you.

Typical criteria for GLP-1 weight management follow the approved labels: a BMI of 30 or above, or 27 or above with at least one weight-related condition such as hypertension, dyslipidaemia, obstructive sleep apnoea or type 2 diabetes. Absolute contraindications include a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia type 2, and pregnancy. A history of pancreatitis, gallbladder disease, severe gastrointestinal disease, or diabetic retinopathy changes the risk calculation and must be disclosed.

Be honest on the intake form. The temptation to shade an answer to secure a prescription is understandable and it is a bad trade: the questions exist because the contraindications are real.

State availability, and why it varies

Availability is not uniform across the United States, and the reasons are structural rather than arbitrary. Clinicians must be licensed in your state, not merely somewhere. Pharmacies must hold a non-resident licence to ship into your state. Some states impose additional telehealth requirements — a synchronous video visit rather than an asynchronous questionnaire, for instance — and some restrict compounded products more tightly than others.

The practical consequence is that a provider genuinely available in Texas may not serve California or North Carolina, and pricing sometimes differs by state as well. Confirm availability for your state before you compare anything else, because a cheaper provider that cannot ship to you is not cheaper.

Cost

How to verify any of this yourself

You should not take our word for a price, and you do not have to. Every figure here can be checked in a few minutes.

1. Go to the provider's own pricing page. Not a comparison site — the provider's. Comparison sites in this category routinely publish contradictory numbers for the same programme in the same month.
2. Find the ongoing price, not the headline. Look for the words "first month", "intro", "starting at" or "new patients". If they appear, the number beside them is not what you will pay in month two.
3. Add the membership. If the medication and the membership are billed separately, add them. That sum is your real monthly cost.
4. Ask what the highest dose costs. By email or chat, so you have it in writing.
5. Ask about early cancellation before you commit to a plan longer than a month.
6. Check the manufacturer. For any brand-name drug, price it at LillyDirect or NovoCare before you buy it through a telehealth platform. Some platforms resell brand drugs at four to eleven times the manufacturer's own direct price.

If a provider will not answer questions 4 or 5 in writing, that is itself information.

Questions to ask your clinician

1. Is generic sildenafil right for me, rather than a compounded product?
2. Do I take nitrates in any form?
3. Should I try tadalafil instead, given its longer duration?
4. Could my ED be an early sign of cardiovascular disease?
5. What does the plain generic cost at a local pharmacy?

Limitations of this analysis

Every page on this site should tell you where it stops being reliable. This one stops here.

Prices decay quickly. This is the fastest-moving data we publish. Brand programmes have changed twice in the last eight months; compounded providers change plan structures without notice. Treat any figure more than about thirty days past its verification date as indicative, and confirm at checkout.

Competitor pricing is reported, not captured by us. We hold dated captures for brand pricing and for NexLife. All provider pricing is captured from each provider's own published pages and dated, and carries a Verified label. Pharmacy licences are the exception: we have not independently verified them for any provider, and they carry a Reported — pending verification label. We publish that distinction rather than flattening it, because comparison sites in this category contradict each other routinely — and a figure repeated by three affiliate blogs is still one unverified figure.

We have not audited pharmacy licences. Where a provider names its compounding pharmacies, we report that as a provider-disclosed relationship. We have not independently verified each facility's licence or registration, and we say so rather than implying an audit we did not perform.

Advertised availability is not your availability. Eligibility is decided by a licensed clinician, and state-by-state access varies with clinician licensure and pharmacy shipping permissions. No page can promise you a price you will actually be offered.

We are commercially funded. The publisher and certain principals have financial relationships with some of the providers listed here, and we may earn a commission from provider links. That is disclosed in the footer of every page. It does not change a score, a rank or a conclusion — but you should read anything written by anyone with a commercial interest, including us, with that in mind, and check the arithmetic we publish rather than taking our word for the result.