ED Medication Comparison Tool
Tadalis SX
20 mg Tadalafil
36 hrsViagra
50 mg Sildenafil
4–6 hrsLevitra
10 mg Vardenafil
4–6 hrsStendra
100 mg Avanafil
6–8 hrsRecommended Option:
Key Takeaways
- Tadalis SX is a 20mg tadalafil tablet marketed for erectile dysfunction with a 36‑hour window of effectiveness.
- Compared with sildenafil (Viagra) and vardenafil (Levitra), tadalafil offers the longest duration but a slightly slower onset.
- Avanafil (Stendra) provides the fastest onset (15‑30min) but lasts only about 6‑8hours.
- Side‑effect profiles are similar across PDE5 inhibitors; individual tolerance and drug interactions drive the best choice.
- In the UK, all these medicines require a prescription, but price varies widely between brand, generic, and online pharmacy options.
What is Tadalis SX?
When you see Tadalis SX is described as a 20mg tablet of tadalafil specifically formulated for erectile dysfunction (ED). It belongs to the PDE5 inhibitor class, which works by relaxing the smooth muscle in the penis and increasing blood flow during sexual stimulation. Tadalis SX was launched in the UK in 2022 and quickly became popular because it offers the same active ingredient as the well‑known brand Cialis but at a lower price point.
Key attributes of Tadalis SX:
- Active ingredient: tadalafil
- Strength: 20mg per tablet
- Typical onset: 30‑60minutes
- Effective window: up to 36hours
- Half‑life: ~17.5hours
Because of its long half‑life, many users call it the “weekend pill” - you can take it on Friday night and still have activity potential on Sunday without a second dose.
Other Popular PDE5 Inhibitors
To decide whether Tadalis SX is right for you, compare it with the other major players in the ED market.
Sildenafil (brand name Viagra) is the original PDE5 inhibitor, approved in 1998. It is usually taken at 50mg or 100mg, with an onset of 30‑90minutes and a duration of 4‑6hours.
Vardenafil (brand name Levitra) works similarly to sildenafil but has a slightly quicker onset (15‑30minutes) and a comparable duration of 4‑6hours.
Avanafil (brand name Stendra) is the newest on the block. Doses range from 50mg to 200mg, onset can be as fast as 15minutes, and its effect lasts about 6‑8hours.
Side‑Effect Snapshot
All four drugs share a core set of side effects because they all inhibit the same enzyme (PDE5). Typical reactions include headache, flushing, nasal congestion, upset stomach, and mild visual changes. The frequency and severity depend on dose, individual health, and concurrent medications.
Rare but serious concerns - such as sudden vision loss (NAION) or hearing loss - are listed on the UK Medicines and Healthcare products Regulatory Agency (MHRA) product information for each drug. Patients with cardiovascular disease, especially those on nitrates, must avoid all PDE5 inhibitors.
How to Choose the Right ED Pill for You
Below is a quick decision matrix you can use while talking to your GP or urologist.
- Need a long window? Opt for tadalafil (Tadalis SX or generic). Ideal for spontaneous plans.
- Want a rapid onset? Avanafil (Stendra) is the fastest, followed by vardenafil (Levitra).
- Budget‑conscious? Generic tadalafil (including Tadalis SX) is usually cheaper than brand‑name sildenafil or avanafil.
- Have liver or kidney issues? Tadalafil’s longer half‑life means lower daily exposure; however, dose adjustment may be needed for severe impairment.
- Take daily medications? Check for interactions - especially with alpha‑blockers, antihypertensives, and certain antifungals.
Price and Availability in the UK (2025)
All the medicines listed require a prescription in the United Kingdom. However, the cost varies markedly between NHS prescriptions, private pharmacies, and reputable online services.
| Brand | Generic Name | Typical Dose | Onset | Duration | Prescription? | Approx. Cost (per tablet) |
|---|---|---|---|---|---|---|
| Tadalis SX | tadalafil | 20mg | 30‑60min | 36hr | Yes (NHS/Private) | £0.85 (online UK pharmacy) |
| Cialis | tadalafil | 20mg | 30‑60min | 36hr | Yes | £1.30 (high‑street) |
| Viagra | sildenafil | 50mg | 30‑90min | 4‑6hr | Yes | £1.10 (online) |
| Levitra | vardenafil | 10mg | 15‑30min | 4‑6hr | Yes | £1.20 (online) |
| Stendra | avanafil | 100mg | 15‑30min | 6‑8hr | Yes | £1.50 (online) |
Prices shown are averages for a single tablet purchased through a reputable UK‑licensed online pharmacy as of September2025. Bulk packs (e.g., 10‑tablet boxes) usually bring the per‑tablet cost down by 15‑25%.
How to Use Tadalis SX Safely
- Take one tablet with water, preferably on an empty stomach for faster absorption.
- Do not exceed one dose in a 24‑hour period.
- If you miss a dose (unlikely with on‑demand use), simply wait until you can take the next dose as needed.
- Avoid heavy alcohol intake; it can increase the risk of dizziness and reduce effectiveness.
- Discuss any heart conditions, blood pressure meds, or nitrate use with your doctor before starting.
Common Questions About Tadalis SX and Its Alternatives
Frequently Asked Questions
Can I buy Tadalis SX without a prescription in the UK?
No. Tadalafil is classified as prescription‑only medicine in the United Kingdom. You need a valid NHS or private prescription, which can be obtained after a consultation with your GP or a licensed tele‑health provider.
Is Tadalis SX the same as Cialis?
Chemically, yes - both contain tadalafil. The difference lies in branding, price, and packaging. Tadalis SX is marketed as a cost‑effective alternative, but the dosage (20mg) and pharmacokinetics are identical to the standard Cialis tablet.
Which drug works fastest?
Avanafil (Stendra) typically shows an effect within 15minutes, making it the quickest onset among the listed options. Vardenafil (Levitra) also offers a rapid onset (15‑30minutes), while tadalafil (Tadalis SX) and sildenafil (Viagra) usually need 30‑60minutes.
Are there any foods or drinks I should avoid?
Heavy, fatty meals can delay absorption of all PDE5 inhibitors, especially sildenafil. Grapefruit juice may increase blood levels of tadalafil, potentially raising side‑effect risk. Moderate alcohol is usually fine, but excessive drinking can cause dizziness and diminish effectiveness.
What if I experience a painful erection lasting more than 4 hours?
A prolonged erection (priapism) is a medical emergency. Seek immediate help at the nearest emergency department. The condition is rare but can occur with any PDE5 inhibitor, especially at higher doses or when combined with other vasodilators.
Bottom Line: Which One Wins?
There is no universal "best" drug - the right choice hinges on how you balance onset speed, duration, cost, and personal tolerance. If you value flexibility and want a single dose that can cover a whole weekend, Tadalis SX (or any generic tadalafil) is hard to beat. If spontaneity matters and you can’t wait 30‑60minutes, avanafil or vardenafil may feel more natural. For men on a tight budget, the generic tadalafil tablets you can order online after a prescription usually cost less than branded sildenafil or avanafil.
Talk to your doctor about your health history, other meds, and lifestyle preferences. With the right information, you can pick the pill that fits your life without compromising safety.
