NEW2026 · Text us +1 272-529-4722
A fast-acting, FDA-approved option for ED treatment.
Reviewed by:
Dr. Steve Malen, PharmD
Dr. Steven Blikstein, PharmD
Strength
How would you like to get this medication?
Choose a strength and quantity to continue.
Sildenafil (Viagra) is a prescription medication used to treat erectile dysfunction (ED) in men. It works by boosting blood flow to the penis during sexual stimulation, helping achieve and maintain an erection. Sildenafil belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors, which relax blood vessels and improve circulation. It is taken by mouth as needed, typically 30 minutes to 1 hour before sexual activity, and should not be used more than once per day.
Complete a health screening
A short questionnaire about your health history and current symptoms — takes about 2 minutes.
Provider reviews your answers
A licensed provider reviews your screening answers, typically within 24 hours.
Prescription fulfilled
If approved, your Rx is sent to Invictus Pharmacy and you're notified by text or email. Free nationwide shipping.
Important safety information
There are specific contraindications for Viagra use, ensuring safety and reducing the risk of severe adverse effects.
The following conditions are absolute contraindications for the use of Viagra:
In these contexts, Viagra is not recommended due to the high potential for adverse outcomes.
Several conditions and factors warrant the precautionary use of Viagra:
Considering these warnings allows for informed decision-making and enhances patient safety when Viagra is prescribed, ensuring it aligns with the individual’s health profile.
Sildenafil is the generic version of Viagra. It is chemically identical to Viagra and is used to treat erectile dysfunction by enhancing blood flow to the penis. Sildenafil is often less expensive than brand-name Viagra, making it an accessible option for many patients.
Sildenafil, like Viagra, is used primarily to treat erectile dysfunction. It is also available as a separate formulation, Revatio, used for other medical conditions. The cost-effectiveness of sildenafil makes it a popular choice for those seeking ED treatment.
Sildenafil works by inhibiting specific enzymes in the body, thereby widening blood vessels and improving blood flow. This action is key to helping individuals with erectile dysfunction achieve the desired results. As with any medication, understanding the proper use and potential side effects is essential for safe and effective treatment.
⚠️ Critical Safety Warning:
Sildenafil should never be taken with nitrates (such as nitroglycerin or isosorbide) or nitric oxide donors. This combination can cause a life-threatening drop in blood pressure, leading to fainting, a heart attack, or a stroke. Always inform your doctor about nitrate use before starting sildenafil.
Note: This medication’s generic and brand-name formulations are used interchangeably throughout this article.
Viagra is a well-known medication used to treat erectile dysfunction (ED) in men. The active ingredient in Viagra is sildenafil citrate, which belongs to a group of medicines known as phosphodiesterase type 5 (PDE5) inhibitors.
Viagra was first introduced in 1998 and quickly became one of the most popular treatments for male impotence. It works by increasing blood flow to the penis, helping men achieve and maintain an erection.
Viagra is primarily prescribed for the management of erectile dysfunction for those who experience difficulty achieving or maintaining an erection. Its effectiveness has been demonstrated in numerous clinical trials, thereby establishing its prominent role in the treatment of ED.
Beyond its primary use, Viagra is sometimes used off-label for other conditions:
While Viagra is mainly prescribed for ED, these off-label uses demonstrate its broader potential in managing certain vascular conditions. However, off-label use should always be considered under the guidance of a healthcare professional, as the risks and benefits can vary among individuals.
Uses & Mechanism of Action
Viagra is usually taken orally in tablet form. It should be consumed as needed, generally about 30 minutes to 1 hour before sexual activity. The medication should not be taken more than once within a 24-hour period to avoid potential overdosing.
Viagra is a medication prescribed for treating erectile dysfunction by enhancing blood flow to the penis. It operates as a phosphodiesterase type 5 (PDE5) inhibitor, helping achieve and maintain erections during sexual arousal by relaxing blood vessel muscles.
A prescription from a healthcare provider is typically necessary to obtain Viagra. This ensures proper usage and dosage tailored to the individual's medical condition and any other medications they may be taking, safeguarding health and effectiveness.
Viagra is not classified as a controlled substance. However, it is still prescribed due to the specific medical condition it targets and potential contraindications with other medications, thus necessitating medical advice before use.
Viagra is not approved for women and does not provide the intended benefits for them. If a woman takes Viagra, it might lead to adverse reactions such as nausea or headaches, with no corresponding improvement in sexual function.
Viagra functions effectively through its unique mechanism of action and pharmacokinetics, which together work to alleviate symptoms of erectile dysfunction and support its other uses.
Viagra’s active ingredient, sildenafil, works by targeting an enzyme known as phosphodiesterase type 5 (PDE5) in the body. During sexual arousal, nitric oxide is released in the corpus cavernosum of the penis.
This chemical triggers the production of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscle and dilates blood vessels, increasing blood flow to the penis and causing an erection.
PDE5 hydrolyzes cGMP, thereby promoting muscle contraction and reducing blood flow. Viagra inhibits PDE5, effectively slowing cGMP degradation and enhancing erectile function in the presence of sexual stimulation.
The pharmacokinetic profile of Viagra is characterized by its rapid absorption and metabolism.
Viagra’s effectiveness relies significantly on correct dosage and administration. Prescribed thoughtfully, it can offer optimal efficacy with manageable side effects, tailored to individual patient needs.
Tailoring the dose allows for flexibility in treatment, accommodating individual responses and preferences. It is crucial not to exceed the prescribed daily dose, as higher doses may increase the risk of adverse effects without enhancing therapeutic benefit.
Proper administration enhances Viagra’s efficacy and ensures that patients can experience the desired effects with minimal risk. Following provider instructions is vital to achieving the best therapeutic outcomes while minimizing potential complications.
As with all medications, Viagra may lead to side effects, ranging from mild to severe. Understanding these potential outcomes helps manage expectations and ensures prompt attention when adverse effects occur.
Users of Viagra may experience several common side effects, which are typically mild and temporary:
These side effects are usually self-limiting and tend to subside as the body adjusts. If they persist or cause significant discomfort, seek medical advice.
Serious side effects, though less common, require immediate medical attention due to potential complications:
Monitoring for these symptoms and understanding their significance are essential for the safe use of Viagra, helping mitigate risks associated with its use.
Monitoring and Safety Considerations:
Medications can interact with Viagra, altering its effects and increasing the risk of side effects. Being aware of these interactions is critical for preventing adverse outcomes.
Several medications are known to interact with Viagra, necessitating caution or avoidance:
Discussing all medications and substances with a healthcare provider ensures safe Viagra use by tailoring treatment to individual needs and minimizing interactions.
Viagra is not intended for treating retrograde ejaculation; its primary use is in addressing erectile dysfunction by facilitating penile blood flow. Retrograde ejaculation typically requires different treatments, focusing on the underlying cause rather than employing Viagra.
Viagra can be effective following prostate surgery, though its success varies depending on factors like nerve preservation during the procedure. Individual responses can vary, making it essential to discuss post-operative treatment with a healthcare provider for optimal results.
Administration & Dosage
Viagra typically begins to work within 30 to 60 minutes after ingestion. However, its effectiveness might be delayed if taken with a high-fat meal. For best results, it is recommended to take Viagra on an empty stomach or after a light meal.
The usual recommended dose for Viagra is 50 mg, which can be adjusted based on individual response and tolerance. Depending on the user’s needs and response, this dose can be reduced to 25 mg or increased up to 100 mg as prescribed by a healthcare provider.
Viagra remains in the system for about 4 to 5 hours, during which it helps maintain erection ability upon sexual stimulation. Although its presence can last up to 5 hours, its effectiveness typically diminishes within 2 to 3 hours.
Viagra can be taken daily if prescribed at the appropriate dosage by a healthcare professional, although daily use may not be necessary for those who do not have everyday sexual activities. Consultation with a healthcare provider is advisable to determine the need for daily usage.
Viagra should be stored at room temperature, away from excessive moisture and heat to maintain its effectiveness. Keeping the medication in its original container also helps protect it from humidity and light, which can affect its potency.
Side Effects & Safety
Common side effects associated with Viagra use include headaches, facial flushing, indigestion, nasal congestion, and dizziness. These effects are generally mild and transient but should be reported to a healthcare provider if persistent or bothersome.
Headaches are among the most frequently reported side effects when using Viagra. This side effect, which affects blood vessels, can vary in intensity and duration, generally being mild and resolving without additional treatment.
Individuals with high cholesterol can generally take Viagra, although it's crucial to consult a healthcare provider. Understanding the individual’s cardiovascular health and current medications helps ensure safety and mitigate potential risks of complications.
Viagra may induce a mild, temporary decrease in blood pressure, thus posing a potential risk for those on blood pressure medications. Therefore, consulting a healthcare provider is vital to assess compatibility and manage risk appropriately.
Excessive Viagra intake can heighten the risk of severe side effects like sudden vision changes, dizziness, or prolonged erections, known as priapism, which require urgent medical intervention. It's crucial to adhere to prescribed dosages to avoid these risks.
Interactions & Contraindications
Moderate alcohol consumption is generally safe with Viagra, but excessive drinking can counteract the drug's effectiveness and heighten the risk of side effects such as dizziness or headache, requiring cautious intake for optimal results.
Viagra and lisinopril are usually taken together, as lisinopril manages blood pressure while Viagra treats erectile dysfunction. Monitoring blood pressure levels is essential, as both may lower it, and consulting a healthcare provider is advised.
Cialis and Viagra should not be used concurrently, as this increases the risk of adverse effects without enhancing benefits. Each medication has a different duration of action, requiring separate administration as determined by a medical professional.
Viagra can be used by those with Parkinson's disease, but it's important to consult a healthcare provider due to possible interactions with medications used for Parkinson's, ensuring safety and efficacy in treating erectile dysfunction symptoms.
Combining Viagra with blood thinners can potentially increase bleeding risks and cardiovascular complications. Medical consultation should guide concurrent use to ensure safe management of both erectile dysfunction and any pre-existing health conditions.
Generic & Alternatives
Sildenafil is the generic name for Viagra, sharing the same active ingredient and offering identical therapeutic effects for erectile dysfunction. It is commonly prescribed as a more cost-effective alternative to the brand-name drug.
The key difference between Viagra and Cialis lies in their duration of action; Cialis lasts significantly longer, up to 36 hours, compared to Viagra's 4-6 hours. These differences inform the choice of treatment based on individual needs.
Cialis 20mg and Viagra 100mg are not directly equivalent in dosing, as their formulations affect the body's response differently. A healthcare provider can determine the most appropriate dosage based on therapeutic needs and individual tolerability.
Coverage for Viagra with Blue Cross Blue Shield varies by plan and policy. It's advisable to check directly with your insurance provider for details on coverage, co-pays, and any potential pre-authorization requirements.
Viagra is not typically available over the counter and usually requires a prescription in most regions. This prescription-only status ensures proper dosage and monitoring, maintaining user safety and treatment effectiveness through professional guidance.
