ED Medicines and Nitrates: What to Tell Your Prescriber

By UTCardiothoracicSurgery.com Editorial Team | September 2026

Disclosure: This article may contain affiliate links. If you purchase through a link, a commission may be earned at no additional cost to you. Product-specific statements in this article are attributed to the seller and are not medical evidence.

This article is educational and is not medical advice. It cannot tell you whether any medicine is right or safe for you. Do not start, stop, or change any prescription without guidance from the clinician who prescribes it.

Quick answer: FDA-approved labeling for the ED medicines sildenafil, tadalafil, and vardenafil (PDE5 inhibitors) contraindicates use with nitrate medicines. In plain terms, that means the combination must not be used, because it can cause a sudden, unsafe drop in blood pressure. Tell every prescriber, including a telehealth prescriber, about all nitrate medicines and every other prescription, over-the-counter medicine, and supplement you use before ED treatment begins. If a compounded formula contains several active ingredients, ask for the exact list, because each one matters to this safety review.

ED Medicines and Nitrates: The Short Answer

Can ED medication be taken with nitrates? No. The FDA-approved labels for sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) each list nitrates as a contraindication. That is the strongest warning category in drug labeling.

Labeling describes the concern in direct terms. The sildenafil patient information says the blood pressure drop can be sudden and unsafe and can cause dizziness, fainting, or a heart attack or stroke. The vardenafil label uses similar language for patient counseling. The tadalafil label contraindicates use with any form of organic nitrate, whether taken regularly or only occasionally.

Those warnings are why the first job of an ED prescriber is a complete medication review. The rest of this guide covers what to disclose, why the exact ingredients of a compounded formula matter, and how to prepare for that conversation.

Why Sildenafil and Tadalafil Interact With Nitrates

Both drug groups act on the same body pathway. Nitrates release nitric oxide, and PDE5 inhibitors amplify the effect of nitric oxide signaling. The sildenafil label states that, consistent with these effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the blood-pressure-lowering effect of nitrates. The tadalafil label describes the same finding in clinical pharmacology studies.

Blood-pressure effects also appear without nitrates. The sildenafil label reports that in healthy volunteers a single dose lowered blood pressure modestly, and that larger effects were recorded in patients also receiving nitrates. The nitrate combination is the one labeling treats as off-limits.

Why There Is No Do-It-Yourself Timing Rule

Readers often ask how long to wait between an ED medicine and a nitrate. The labels do not give a safe timing rule for patients. The sildenafil label says it is unknown when nitrates can be safely given after sildenafil, and that it is unknown whether they can be safely co-administered even 24 hours after a dose. The vardenafil label says a suitable time interval has not been determined. The tadalafil label discusses a rare, clinician-managed emergency situation in which a physician decides a nitrate is medically necessary, and says nitrates should then be given only under close medical supervision. That passage is written for clinicians and is not a schedule for readers.

The practical takeaway is to avoid inventing a spacing plan. If you use a nitrate, your ED treatment decision belongs with the clinicians involved in your care.

If you ever need emergency medical care for a heart problem, the sildenafil patient information says it is important for the healthcare provider to know when you last took the ED medicine. Tell the emergency team what you took and when.

Common Prescription Nitrates Readers May Encounter

Nitrate medicines are commonly used for angina (chest pain). Drug references list nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate as examples. The sildenafil patient information itself names nitroglycerin as an example.

Nitroglycerin comes in several dosage forms and brand names, so the product you hold may not say “nitrate” anywhere obvious.
Isosorbide dinitrate and isosorbide mononitrate are longer-acting nitrates that appear under multiple brand and generic names.
Brand names, dosage forms, and routes vary, and this list is not exhaustive.

Do not rely on recognizing the word “nitrate.” Give your prescriber and pharmacist your full medication list and ask them to check it. The sildenafil patient information tells readers who are unsure whether a medicine contains nitrates to ask a healthcare provider or pharmacist.

The labeling also mentions inhaled nitrite products sold as “poppers” (amyl nitrite, butyl nitrate) alongside nitrate medicines. If any such product is part of your life, say so, because the label lists it among the reasons not to take sildenafil.

A distinction worth making: These warnings concern nitrate medicines and inhaled nitrite products. They are not the same thing as nitrates that occur naturally in foods, and ordinary dietary nitrate intake is not equivalent to taking nitrate medication. If you have questions about your diet and ED treatment, ask your prescriber.

Why Your Prescriber Needs Your Full Medication List

Nitrates are the headline interaction, but they are not the only item a prescriber needs to check. FDA-approved labels for these medicines also flag the following:

Guanylate cyclase stimulators such as riociguat (Adempas): the sildenafil and vardenafil labels contraindicate use with these medicines. Check the current label for each ingredient in your exact prescription.
Alpha-blockers (prescribed for prostate symptoms or high blood pressure) and other blood pressure medicines: the labels say PDE5 inhibitors can add to their blood-pressure-lowering effects.
Medicines that change how the body processes PDE5 inhibitors, such as certain HIV protease inhibitors, antifungals, and antibiotics named in the sildenafil patient information.
Other ED treatments or other PDE5 inhibitors, including sildenafil or tadalafil products prescribed for pulmonary arterial hypertension.

Also tell your prescriber about over-the-counter medicines, vitamins, and herbal supplements. The sildenafil patient information asks patients to disclose all of these, and it advises keeping a written list to show every healthcare provider and pharmacist.

ED Medicines, Blood Pressure, and Cardiovascular History

The sildenafil label notes that sexual activity carries a potential cardiac risk in people with existing cardiovascular disease, and that the evaluation of ED should include a complete medical assessment. The patient information advises telling the prescriber about heart problems such as a heart attack, irregular heartbeat, angina, chest pain, heart failure, recent heart surgery, stroke, and low or uncontrolled high blood pressure.

Someone who has been prescribed a nitrate may have an underlying heart condition, but this article cannot assess your situation. Whether ED treatment is appropriate for you is a decision for the treating clinician, who can look at your full history. If you have angina or take heart medicines, that conversation should include the clinician who manages your heart care as well as the ED prescriber.

Do not stop, change, or substitute a prescribed heart medicine in order to use an ED medicine. Bring that question to the prescriber who manages the heart medicine.

Compounded ED Formulas: Why the Exact Ingredients Matter

Some telehealth ED programs offer compounded medicines, which are prepared by a pharmacy to a prescriber's order. A compounded product can contain a single active ingredient or several. The exact ingredients and strengths depend on the prescription, and they may differ from one product or patient to the next. Do not assume that every compounded ED medicine contains sildenafil, or tadalafil, or the same combination as another product.

That variability is why the ingredient list is a safety question:

The nitrate contraindication follows each PDE5 inhibitor in the formula. If a product contains more than one, each one is a reason to disclose nitrates.
The sildenafil label states that combinations with other PDE5 inhibitors or other ED therapies have not been studied, that such combinations may further lower blood pressure, and that they are not recommended. That is label language for an approved single-ingredient product. It does not evaluate any specific compounded formula, so it is a question to put to your prescriber.
Labels for approved products describe those products in their approved forms and routes. They do not establish absorption, safety, or effectiveness for a compounded multi-ingredient liquid or sublingual product.
The non-PDE5 ingredients need their own review. For example, the FDA-approved label for an apomorphine injection (approved for a different use and route) contraindicates use with certain nausea medicines, such as ondansetron, because of reports of profound low blood pressure and loss of consciousness. Whether that applies to a compounded sublingual product is a question for the prescriber and dispensing pharmacist, and this is why you should list every medicine you take.

QMAX as an Example of a Multi-Ingredient Compounded Formula

BetterMe Rx QMAX is one example of a compounded multi-ingredient ED product. Everything in this section comes from BetterMe Rx's own page, checked on September 25, 2026, and is seller information rather than independent medical evidence. You can read it yourself on the BetterMe Rx QMAX seller page.

Ingredients listed by the seller: BetterMe Rx lists four active ingredients: sildenafil (40 mg), tadalafil (4 mg), vardenafil (7.5 mg), and apomorphine (2 mg).
Doses may vary: The same page says QMAX is a compounded prescription product and that active ingredients and dosages are determined by the provider and may vary. Do not assume every patient receives identical ingredients or strengths.
FDA status, in the seller's words: The page states that compounded drugs are not approved by the FDA and that the FDA does not verify their safety or effectiveness.
Seller claims, not established outcomes: The seller describes a roughly 10-minute onset and a window of up to 36 hours, and states that onset and individual results vary. Treat these as the seller's marketing claims, not guaranteed results or independent evidence.

The seller's landing-page text that I reviewed does not discuss nitrates. That is not unusual for marketing text, and the page says a licensed provider reviews an intake before any prescription. I have not seen the intake questions. Whatever product you are considering, it is your job to state your nitrate use and full medication list plainly, and the prescriber's job to act on it.

The example also shows why the ingredient list matters. A product listing three PDE5 inhibitors in one dose raises the same nitrate question three times over, and the label language about combining PDE5 inhibitors (above) is a topic to raise with the prescriber. It does not mean any particular product is unsafe.

Compounded Drugs and FDA Approval: What the Distinction Means

The FDA states that compounded drugs are not FDA-approved. The agency does not review their safety, effectiveness, or quality before they are marketed. A finished compounded formula does not become FDA-approved because one or more of its individual ingredients are used in FDA-approved medicines.

That does not make compounded medicines automatically unsafe or ineffective. The FDA also says compounded drugs can serve an important medical need for patients who cannot be treated with an approved medication, and that compounded drugs should only be used when a patient's medical needs cannot be met by an approved one. The agency notes that quality problems can occur and that labels on compounded drugs may lack important information, such as adequate directions for safe use.

Marketing language about pharmacy registration is a separate matter from approval of the finished drug. The FDA's position is that compounded drugs are not FDA-approved, whatever the pharmacy's status.

Questions to Ask Before Filling an ED Prescription

Which exact active ingredients are in this prescription, and in what strengths?
Is this an FDA-approved product or a compounded one? If compounded, why was it chosen for me?
Have you reviewed my full medication list, including any nitrate medicine, for interactions?
Does anything I take, including over-the-counter medicines and supplements, need special attention with these ingredients?
Given my heart and blood pressure history, should my other clinicians be involved before I start?
Which symptoms mean I should seek urgent care, and who should I contact with questions?

Medication-Safety Checklist

Write down every prescription medicine, with names and forms (tablets, under-the-tongue tablets or sprays, patches, and so on).
Circle any medicine used for chest pain or angina. If you are not sure whether a medicine is a nitrate, ask a pharmacist.
List over-the-counter medicines, vitamins, herbal supplements, and any recreational inhaled products.
List blood pressure medicines, prostate medicines, and any other ED or PDE5 medicine, including sildenafil or tadalafil prescribed for lung blood pressure.
Write down your heart and blood pressure history in your own words: heart attack, stroke, heart surgery, angina, heart failure, low or uncontrolled high blood pressure.
Ask for the exact active ingredients of any compounded prescription in writing, and keep the list with your medicine list.
Give the same list to your pharmacist and to your heart clinician.
Do not start, stop, or change any prescription on your own.

When to Seek Urgent Care

The FDA-approved labeling and patient information for these medicines describe warning signs that need prompt medical attention. Seek urgent or emergency care if any of the following happen after taking an ED medicine, and tell the clinicians what you took and when:

Chest pain, dizziness, or nausea during sexual activity. The sildenafil patient information says to stop sexual activity and get medical help right away.
An erection lasting more than 4 hours.
Sudden loss of vision in one or both eyes.
Sudden decrease or loss of hearing.

For sudden vision or hearing loss, the labeling also tells patients to stop the medicine and seek prompt care. If you are in immediate danger, call 911 or your local emergency number.

Frequently Asked Questions

Can ED medication be taken with nitrates?

No. FDA-approved sildenafil, tadalafil, and vardenafil labels contraindicate use with nitrates because the combination can cause a sudden drop in blood pressure.

Why are nitrates and sildenafil dangerous together?

Both act on the nitric oxide/cGMP pathway. The sildenafil label states that sildenafil potentiates the blood-pressure-lowering effect of nitrates, and the patient information warns of dizziness, fainting, heart attack, or stroke.

Can tadalafil be taken with nitrates?

No. The tadalafil label contraindicates use with any form of organic nitrate, whether taken regularly or occasionally. Do not try to work out a timing gap yourself. Labels for these medicines do not give one for patients.

What medicines count as nitrates?

Examples include nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate, in various forms and under various brand names. Do not rely on spotting the word “nitrate.” Give your prescriber and pharmacist your complete medication list.

Why should I tell my ED prescriber about heart medicines?

Because nitrates are contraindicated and because other heart and blood pressure medicines can add to the blood-pressure-lowering effects of ED medicines. Only a clinician who knows your full history can weigh those factors.

What if a compounded ED formula contains several active ingredients?

Ask for the exact list and strengths, because the nitrate warning applies to each PDE5 inhibitor in the formula, and each other ingredient needs its own review. The sildenafil label says combinations with other PDE5 inhibitors have not been studied and are not recommended, which is worth raising with your prescriber.

Is a compounded ED medication FDA approved?

No. The FDA states that compounded drugs are not FDA-approved, which means the agency does not review their safety, effectiveness, or quality before they are marketed. That does not mean they are automatically unsafe or ineffective.

What information should I give my prescriber before ED treatment?

Your full medication list (prescription, over-the-counter, supplements), any nitrate or chest-pain medicine, blood pressure medicines, other ED treatments, any recreational inhaled products, and your heart and blood pressure history.

Sources and Related Reading

Primary sources:

Related reading on this site:

Compounded ED Combinations and Heart Medications: Nitrates, Blood Pressure, and Cardiac Safety for a broader look at cardiac-safety considerations and other named compounded products.
PDE5 Inhibitors and Blood Pressure Medications: Drug Interactions Every Man on Cardiac Meds Should Understand for how PDE5 inhibitors interact with blood pressure medicines.

This article was prepared by the UTCardiothoracicSurgery.com Editorial Team for informational purposes. It does not constitute medical advice or a treatment recommendation. Discuss all medication decisions with a qualified healthcare professional and your pharmacist. UTCardiothoracicSurgery.com is an independent editorial publication and is not affiliated with any hospital, medical practice, or university program.