No. Cialis (tadalafil) is classified as a Prescription Only Medicine (POM) in the United Kingdom. Unlike some over-the-counter treatments, you cannot buy Cialis without a valid prescription from a UK-registered prescriber. Any online pharmacy or retailer offering Cialis without prescription is operating outside legal regulations. To ensure safety, quality and legal compliance, Cialis must be prescribed by a qualified healthcare professional who assesses your medical history, conditions and drug interactions.
The Medicines and Healthcare products Regulatory Agency (MHRA) classifies medicines into three main categories:
Cialis is POM because it requires professional assessment of cardiac, renal, hepatic status, and potential interactions with nitrates or other contraindicated drugs.
Cialis is a brand name for the active ingredient tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED) and sometimes benign prostatic hyperplasia (BPH). It helps maintain an erection by increasing blood flow to the penis in response to sexual stimulation.
Tadalafil is a selective PDE5 inhibitor. It works by blocking the enzyme PDE5, which leads to an accumulation of cyclic guanosine monophosphate (cGMP) in smooth muscle cells, causing relaxation and increased blood flow in the corpus cavernosum.
Cialis has a long half-life of approximately 17.5 hours, providing erectile support for up to 36 hours after a single dose, which is longer than sildenafil (Viagra) or vardenafil (Levitra).
Generic tadalafil contains the same active ingredient at bioequivalent doses. Manufacturing, excipients and branding differ, but therapeutic effects, safety profile and approved indications are the same under MHRA licensing.
Cialis is commonly available in 5 mg, 10 mg and 20 mg strength tablets. The starting dose for most patients is 10 mg taken before anticipated sexual activity. Lower daily doses (5 mg) are also approved for regular daily use in men who anticipate frequent activity.
PDE5 breaks down cGMP, a second messenger responsible for relaxing smooth muscle in the corpus cavernosum. Inhibition of PDE5 increases cGMP, thereby enhancing and prolonging erections.
In many men, Cialis produces an erection sufficient for intercourse within 30 to 60 minutes. Onset can vary based on individual factors such as age, body weight, diet and concomitant medications.
Cialis absorption is not significantly influenced by fatty meals, unlike some other ED medications. Patients may take it with or without food.
Prolonged erections lasting more than four hours (priapism) are a medical emergency. If an erection persists beyond four hours, immediate medical attention is necessary to prevent tissue damage.
Cialis does not directly affect sexual desire. It facilitates physiological mechanisms for erection in response to sexual stimulation but does not act as an aphrodisiac.
Prescription charges, private prescriptions and online pricing vary. Brand-name Cialis is typically more expensive than generic tadalafil. Prices depend on pack size, dosage strength and pharmacy pricing policy.
Online pharmacies may offer discounts by purchasing generics in bulk, reducing overhead costs, or running promotional offers. Always verify MHRA registration and prescription requirements to avoid counterfeit products.
| Example | Strength | Pack Size | Price | Status | Note |
|---|---|---|---|---|---|
| Brand Cialis | 10 mg | 4 tablets | £45.00 | POM | Prescription required |
| Generic tadalafil | 10 mg | 8 tablets | £30.00 | POM | Prescription required |
| Generic tadalafil | 20 mg | 4 tablets | £28.00 | POM | Prescription required |
Prices shown are for illustrative purposes. For current pricing and offers, contact Elstree Pharmacy.
Cialis is available as tablets containing 5 mg, 10 mg or 20 mg tadalafil. The 5 mg dosage is also licensed for once-daily use in men who prefer spontaneity.
Cialis tablets are film-coated oral dosage forms. There are no injectable or sublingual formulations authorised in the UK for tadalafil.
Pack sizes may include 2, 4, 8, 12, or 28 tablets depending on strength and intended use (on-demand versus daily therapy). Prescription instructions will specify the number of tablets dispensed.
Yes. A larger pack intended for prolonged treatment may require additional pharmacy controls or a private prescription for repeat supply. Always confirm pack details with your pharmacist.
| Feature | Why it matters |
| Strength | Determines dose and frequency |
| Formulation | Oral tablet, film-coated |
| Pack size | Impacts legal supply and duration |
| Brand vs generic | Affects price, excipients and manufacturer |
Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It can result from vascular, neurological, psychological or endocrine causes.
Tadalafil is also licensed for treatment of benign prostatic hyperplasia (BPH) under the brand Cialis 5 mg once daily. It helps reduce urinary symptoms associated with prostate enlargement.
Tadalafil is not licensed for sexual dysfunction in women. Off-label use is not recommended without specialist supervision.
On-demand dosing uses 10–20 mg doses taken prior to sexual activity. Daily dosing uses 2.5–5 mg once daily to allow spontaneous activity without planning.
Patients taking nitrates, nitric oxide donors or guanylate cyclase stimulators should not take tadalafil due to the risk of serious hypotension.
Cialis requires prescription because of potential interactions, the need to assess cardiovascular status, and contraindications with nitrates or some antihypertensives.
No. All PDE5 inhibitors in the UK are POM due to safety considerations. Lower risk medications like some topical creams exist but are unlicensed and not recommended.
The MHRA and Department of Health determine legal categories based on safety, indication and professional oversight needs.
Yes. Reclassification may occur if new safety data emerges or treatment paradigms shift, but tadalafil remains POM as of 2026.
Alprostadil works via a prostaglandin analogue mechanism. Mechanical devices require training for correct use.
Smoking cessation, weight management, reduced alcohol consumption, controlling blood sugar and stress management can improve erectile function.
Both are PDE5 inhibitors. Cialis has a longer duration (up to 36 hours) and less food interaction. Viagra onset may be faster in some men but lasts 4–6 hours.
Spedra (avanafil) has a rapid onset (as little as 15 minutes) but shorter duration (6–12 hours) compared with Cialis.
| Feature | Cialis | Viagra | Spedra |
| Active ingredient | Tadalafil | Sildenafil | Avanafil |
| Onset | 30–60 min | 30–60 min | 15–30 min |
| Duration | Up to 36 h | 4–6 h | 6–12 h |
| Food effect | Minimal | High-fat food slows absorption | Minimal |
No. Choice depends on dosing flexibility, duration, comorbidities, drug interactions and patient preference.
Heart-healthy diets (Mediterranean style) can improve vascular function and erectile health.
Excessive alcohol may impair arousal and response. Moderate intake may be tolerated by some men but heavy drinking is detrimental.
Smoking is a major risk factor for ED due to vascular damage. Quitting can improve outcomes.
Regular aerobic and resistance training improves cardiovascular health and erectile function.
Yes. Common side effects include headache, indigestion, back pain, muscle aches, flushing and nasal congestion. Most are mild and transient.
| Area | Examples described in product information |
| Head and neck | Headache, flushing, nasal congestion |
| Gastrointestinal | Dyspepsia, nausea |
| Musculoskeletal | Back pain, myalgia |
| Vision | Rare changes in colour vision or increased light sensitivity |
| Hypersensitivity | Rare allergic reactions, angioedema |
Rarely, tadalafil may cause sudden hearing loss, non-arteritic anterior ischaemic optic neuropathy (NAION), or priapism. Seek immediate care if these occur.
Daily dosing is approved and well studied. Long-term safety mirrors on-demand, but patients must monitor cardiovascular status and vision.
Single doses above 20 mg increase risk of side effects without added efficacy. Do not take more than one dose per day.
Persistent ED can indicate cardiovascular disease, diabetes, hormonal imbalance or psychological conditions that require medical evaluation.
Yes. Potent CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) raise tadalafil levels. Nitrates or nitric oxide donors cause severe hypotension. Patients on alpha-blockers must be stable before coadministration.
Grapefruit juice can increase tadalafil exposure; avoid large quantities to reduce risk of adverse effects.
Cialis is not indicated in women; it is contraindicated during pregnancy and breastfeeding.
Generic tadalafil is bioequivalent to brand Cialis and meets the same regulatory standards. It may differ in appearance and excipients.
Different products may have varying pack sizes, patient leaflets, excipients and dosage schedules. Always read the patient information leaflet supplied with your prescription.
Reliable sources include the MHRA, electronic Medicines Compendium (eMC) and professional healthcare guidance. Elstree Pharmacy can provide patient leaflets and counselling.
No. This information is for general guidance. For personalised advice, consult the pharmacy team at Elstree Pharmacy (The Corner Shop B, High Street, Elstree, WD6 3BY) or your GP.
