BorderFreeHealth Sildenafil Medication Overview

Sildenafil is a prescription medicine used to treat erectile dysfunction and, in different dosing, pulmonary arterial hypertension. This page summarizes how the medication works, dosage basics, and important safety points in plain language. It also explains how prescriptions are handled for cash-pay access for people without insurance, including US shipping from Canada.

Information here is meant to help with navigation and expectations, not to replace the instructions from a licensed prescriber. For condition-specific browsing, see the Erectile Dysfunction and Pulmonary Hypertension hubs, which list related options and strengths.

What Sildenafil Is and How It Works

This medicine belongs to a class called phosphodiesterase type 5 (PDE5) inhibitors. In erectile dysfunction (ED), PDE5 inhibition helps preserve cyclic GMP, a signaling molecule involved in smooth-muscle relaxation and blood flow to penile tissue during sexual stimulation. Because the pathway depends on arousal, the tablet does not “create” an erection on its own; it supports the body’s normal response.

For pulmonary arterial hypertension (PAH) (high blood pressure in the lung arteries), the same drug class can help relax blood vessels in the lungs to improve exercise capacity in some people. Prescriptions are confirmed with the original prescriber before dispensing.

Who It’s For

Sildenafil is most commonly prescribed for ED in adult men. It is also prescribed under different brand names and dosing schedules for PAH in adults, and in select cases in pediatrics under specialist care. The specific indication matters because dosing, frequency, and monitoring can differ. A clinician will choose the appropriate regimen based on diagnosis, other conditions, and current medications.

This treatment is not appropriate for everyone. It should not be used with nitrate medicines (often used for chest pain) because the combination can cause dangerous hypotension (low blood pressure). Caution is also important for people with certain heart conditions where sexual activity is not advised, those with recent stroke or heart attack, significant liver or kidney impairment, certain inherited eye disorders, or a prior episode of non-arteritic anterior ischemic optic neuropathy (NAION) (sudden optic nerve injury). If there is any uncertainty, the prescriber and pharmacist should review the full medication list and history.

Dosage and Usage

For erectile dysfunction, Sildenafil tablets are typically taken “as needed,” not on a fixed daily schedule, and are generally used before sexual activity. Labels often recommend a single dose in a 24-hour period, with timing that may be around an hour before activity, though some people notice effects sooner or later. High-fat meals can delay onset for some PDE5 inhibitors, so instructions may mention food considerations.

For PAH, dosing is commonly lower per dose and taken on a regular schedule (often three times daily) to support steady effects in the pulmonary circulation. The exact product and directions differ by indication, so it is important to follow the prescription label rather than copying a regimen from ED instructions.

• Read the label each refill: directions may change by indication.
• Take only the prescribed amount: do not combine with other ED drugs.
• Record side effects: share patterns with the prescriber.

Strengths and Forms

This medicine is most often supplied as oral tablets. For ED, tablets are commonly available in 25 mg, 50 mg, and 100 mg strengths, while PAH regimens may use different strengths such as 20 mg; availability can vary by pharmacy and by the specific prescription. Sildenafil is also manufactured in other forms in some markets (for example, an oral suspension for PAH), but the ordered form depends on what is written on the prescription.

The strength matters for more than “how strong it feels.” It can change the likelihood of side effects, the impact on blood pressure, and the suitability alongside other medications. If a prescriber changes dose, pharmacies may dispense a different tablet size or directions, and patients may be asked to avoid splitting tablets unless the product is designed for it.

Storage and Travel Basics

Store tablets at room temperature, away from heat, moisture, and direct light. Bathrooms and hot cars can expose medicines to humidity and temperature swings that may degrade tablets over time. Keep the product in the original blister pack or bottle until use, and store it out of reach of children and pets.

Quick tip: Keep a photo of the label for refill and travel reference.

For travel, carry the medication in hand luggage with the pharmacy label attached, since loose tablets can be hard to identify and may raise questions at security. If a dose is missed for a scheduled PAH regimen, follow the prescriber’s instructions; do not double up unless specifically directed on the label. If a tablet becomes discolored, crumbles, or smells unusual, ask a pharmacist before using it.

Side Effects and Safety

Like other PDE5 inhibitors, Sildenafil can cause side effects related to blood vessel relaxation and smooth-muscle effects. Commonly reported effects include headache, facial flushing, nasal congestion, indigestion, nausea, dizziness, and mild visual changes (such as a blue tinge or increased light sensitivity). Some people notice muscle aches or back discomfort. These effects are often dose-related and may be more noticeable when starting or when combined with alcohol.

More serious reactions are uncommon but require urgent attention. Seek emergency care for chest pain, fainting, severe shortness of breath, sudden vision loss, sudden hearing loss or ringing with hearing changes, or signs of an allergic reaction (swelling of the face or throat, hives, trouble breathing). Priapism (an erection lasting longer than four hours) is a medical emergency because it can cause lasting injury. People with significant cardiovascular disease should discuss whether sexual activity is safe before using any ED medicine.

Drug Interactions and Cautions

Drug interactions are a major safety issue for PDE5 inhibitors. Nitrates (including nitroglycerin tablets, sprays, and patches) must not be used with this medicine because blood pressure can drop to dangerous levels. Riociguat, used for certain pulmonary hypertension conditions, is also generally contraindicated with PDE5 inhibitors. Alpha-blockers for prostate symptoms or blood pressure may increase the risk of dizziness or fainting, so prescribers may adjust timing or dosing.

Why it matters: Mixing nitrates with ED drugs can cause life-threatening low blood pressure.

Some medications can raise blood levels of the drug by inhibiting CYP3A4 (a liver enzyme), including certain HIV medicines (for example, ritonavir) and some antifungals or macrolide antibiotics; others may lower levels. Grapefruit products can also affect metabolism for some people. Disclose over-the-counter drugs and supplements, and avoid taking multiple ED therapies at the same time unless explicitly directed. Medicines are dispensed through licensed Canadian partner pharmacies.

Compare With Alternatives

Several prescription options treat ED by targeting the same physiologic pathway, but they differ in how long effects may last, how food affects timing, and how dosing is commonly written. Sildenafil is often used as an on-demand option, while tadalafil may be chosen when a longer window of effect is preferred. Vardenafil and avanafil are other oral PDE5 inhibitors with their own labeling and interaction cautions.

Non-oral options may be considered when tablets are not appropriate, such as alprostadil (an intraurethral pellet or injection in some settings) or vacuum erection devices. For reading that compares common ED choices, see Cialis Vs Viagra, Viagra And Cialis Differences, and Levitra Vs Cialis. Alcohol can also affect side effects and performance; Cialis And Alcohol provides practical context that often applies across this medication class.

For site browsing, related prescription products include Tadalafil and Viagra. A clinician can help select an option based on medical history, other medications, and treatment goals.

Pricing and Access

Costs can vary by strength, quantity, and the specific manufacturer dispensed. Many people compare options when paying cash; BorderFreeHealth supports cross-border access to prescription medication for U.S. patients through Canadian partner pharmacies, with prescription verification before dispensing. Cash-pay access supports those without insurance.

To explore related categories on the site, browse the Mens Health collection. If available, Current Promotions may reduce out-of-pocket costs for eligible prescriptions, depending on product and rules. Sildenafil still requires a valid prescription, and the pharmacy may contact the prescriber to confirm details or clarify directions.

Authoritative Sources

The most reliable details on indications, contraindications, and interactions come from official labeling and regulator-supported references. For clinical decisions, patients should use these sources alongside advice from a licensed healthcare professional who can account for individual risk factors and the full medication list.

The links below provide baseline safety information and label-aligned warnings. They are useful for checking interaction red flags (like nitrates), reviewing serious side effects, and understanding why ED and PAH dosing differ across products.

• FDA product and labeling overview for Viagra: Drugs@FDA Application Overview
• NIH consumer medication information summary: MedlinePlus Drug Information

To place a refill request through the site, upload your prescription and select prompt, express shipping at checkout when available.

This content is for informational purposes only and is not a substitute for professional medical advice.