Sildenafil Ingredients

Sildenafil is the generic drug name for the popular erectile dysfunction treatment Viagra. It is also used at a lower dose to treat patients suffering with pulmonary arterial hypertension (PAH), under the brand name Revatio.

Sildenafil is the name of the active ingredient in the medication. For erectile dysfunction patients, Sildenafil works by causing a release of nitrous oxide, a chemical that enlarges the blood vessels in the penis and therefore aids a man’s ability to achieve an erection during sexual intercourse.

But besides Sildenafil itself, there are several more ingredients used in the drug – mostly included to form the drug into a consumable tablet. Below are some of the other substances that make up the drugs generic Sildenafil, Viagra and Revatio.

Microcrystalline Cellulose


A texturiser, emulsifier and anti-caking agent used in the production of foods and medications. It’s most commonly used in the making of vitamin tablets and pills. It is actually made of refined wood pulp, but it is perfectly safe for consumption. It is an inactive ingredient, meaning it does not add any ‘therapeutic action’ to the drug; it just binds the drug together into the form of an ingestible tablet.


Anhydrous Dibasic Calcium Phosphate


This is a tableting agent commonly used in pharmaceutical products. In medications, it is mainly just an inactive component: another ingredient that simply makes up the tablet and has no therapeutic property.

Croscarmellose Sodium


This ingredient is a superdisintegrant (another term for ‘excipient’, which is a substance used alongside a medication’s active ingredient that bulks up the formulation, helps with drug absorption, and aids with long-term stabilisation). It can also act as an emulsifier. Perhaps its main function is for absorption – it allows the tablet to take in water and swell, helping it to dissolve after consumption by the patient.

Magnesium Stearate


This ingredient is used in practically all supplements and drugs. Sometimes it will be listed as ‘steric acid’ or ‘vegetable stearate’ on ingredients lists. It is certifiably safe in the tiny doses found in pills, but it could be dangerous in very large quantities. It is a magnesium salt and a stearic acid, or a compound that contains magnesium and two stearic acids. Stearic acid is a fatty acid found in many naturally occurring substances, including vegetable fats, flaxseeds and cocoa.

It is less of an ‘ingredient’ and more of a production aid – it quickens the process of manufacturing pills because it prevents the ingredients from sticking to the equipment used to form the tablets. It also makes the pills easier for patients to swallow.



This is a semi-synthetic polymer used as an excipient in medications. It is also a controlled-delivery component for oral medications, meaning that it helps in releasing the active ingredient steadily after consumption rather than all at once.

Titanium Dioxide


This is mainly used as a pigment in medications and hygiene products, known as ‘titanium white’ for its bright-white colour.



Lactose is a disaccharide, which is a sugar formed by two monosaccharides – in this case, glucose and galactose. It is commonly added to medical products because it aids compressibility of tablets and is cost-effective compared to other similar ingredients.

Patients should be aware, however, if there is lactose in their medications if they are allergic to the substance. Although it is included in a miniscule dose, it can affect someone who is severely allergic. A doctor will be able to advise if medications containing lactose are suitable for you if you suffer from a lactose allergy. Do not take the medication without consulting with a doctor first.



Also known as glycerine triacetate, this ingredient is liquid in form and is commonly included as a food additive and a solvent in medications. It is also used as an excipient.



In the case of Viagra, the pill gets its famous bright-blue hue from the colouring ingredient ‘FD and C Blue #2 Aluminium Lake’, according to This is an inactive ingredient used only for colour and is classified as completely safe by the Food and Drug Administration (FDA) in the USA.


Drug Labelling


Consumers should ALWAYS read the ingredients list and directions for every drug they take. This is to check for ingredients known to cause allergies or intolerances in the patient. Always consult with a doctor before taking any new medication.

About Maryam BenhamDr Maryam Benham obtained her medical degree in medicine in Iran in October 2004 and moved to the UK in 2006 and has held full registration with the General Medical Council since 2007. Maryam finished her foundation training at Ealing hospital and has done two years of surgery in different London hospitals such as Royal Free Hospital before deciding to pursue specialist training in General Practice at Kent, Surrey and Sussex (KSS) Deanery in 2011. Since finishing her GP training in September 2014 Maryam has been a dedicated General Practitioner in London.

With special interest in Dermatology, Aesthetics and minor skin procedures alongside her NHS work as a general practitioner, Maryam stays updated in her areas of interest through attending seminars and minor surgery and aesthetic courses. As part of the new generation of highly dedicated and skilled British doctors, Maryam believes that her main aim is to deliver the best care to her patients and to provide them with the best possible medical advice.
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