The long-acting treatment for erectile dysfunction — one dose can last up to 36 hours, available daily or as-needed, prescribed online by a licensed provider and shipped discreetly from U.S. pharmacies to all 50 states.
Your price depends on the dose your provider prescribes
$50/mo Most people start here
A few private questions, then a licensed provider reviews your answers.
Tadalafil is the generic form of Cialis® — a PDE5 inhibitor approved for erectile dysfunction and for the urinary symptoms of an enlarged prostate (BPH). As a generic, it contains the identical active ingredient to the brand at a far more accessible price.
Its defining feature is duration. Where most ED medications last a few hours, a single dose of tadalafil can support erections for up to 36 hours — which is why it's widely known as the "weekend pill." It can be taken as a low daily dose for always-ready spontaneity, or as a higher dose only when needed.
Because it relies on natural arousal to work, tadalafil supports your body's own response rather than overriding it. A licensed provider reviews your health history and selects the dose and schedule that fit your goals during your online visit.
Erectile dysfunction usually comes down to blood flow — an erection depends on blood vessels relaxing and filling the penis, and anything that narrows or stiffens those vessels can make erections harder to achieve or keep. Common contributors include age, cardiovascular and metabolic health, stress and anxiety, certain medications, and lifestyle factors. It's one of the most common conditions men face, and for most men it's very manageable with the right treatment.
ED affects a large share of men and becomes more frequent with age — it's a routine medical concern, not a reason for embarrassment, and providers treat it every day.
PDE5 inhibitors like tadalafil are a first-line option that helps most men. If ED is affecting your confidence or your relationship, that alone is reason enough to talk to a provider.
The short answer: tadalafil lasts far longer than any other oral ED tablet (up to 36 hours vs. 4–6), over-the-counter "supplements" aren't FDA-regulated ED treatments, and only a prescription option comes with a licensed provider reviewing your health first.
| OTC supplements | Sildenafil (Rx) | Tadalafil (Rx) | |
|---|---|---|---|
| What it is | Unregulated herbal "boosters" | Generic Viagra®, a PDE5 inhibitor | Generic Cialis®, a PDE5 inhibitor |
| How long it lasts | Not established | 4–6 hours | Up to 36 hours |
| When you take it | Varies | As-needed, ~1 hr before | Daily or as-needed |
| Provider reviewed | No | Yes | Yes |
| Affected by food | Varies | Slowed by heavy meals | Not significantly |
| Also treats BPH | No | No | Yes |
Many men start with over-the-counter supplements, find the results unreliable, and move to a prescription PDE5 inhibitor. Between the two most common tablets, tadalafil's up-to-36-hour window is what sets it apart from sildenafil's shorter 4–6 hours.
It works through the same mechanism as sildenafil — blocking the PDE5 enzyme so blood vessels relax and blood flows in when you're aroused — but it stays active in your body far longer, which is why one dose covers a much wider window.
Tadalafil inhibits the PDE5 enzyme, which normally breaks down the signal that allows an erection to form — and it does so for far longer than shorter-acting options.
With PDE5 paused, blood vessels relax and circulation to the penis increases whenever you're aroused — across a much longer window of time.
The result is a firmer erection that's easier to achieve and maintain — with natural arousal still required, and no need to time the dose to the moment.
It's for men who value spontaneity over scheduling — if planning treatment around a specific hour feels limiting, tadalafil's long duration removes that pressure entirely.
One dose can cover an entire weekend, so intimacy doesn't have to be planned around a pill.
A low daily dose (2.5–5 mg) keeps tadalafil working in the background so you're ready anytime, no advance timing needed.
If a 4–6 hour window has felt restrictive, tadalafil's longer duration is a natural next step to discuss with your provider.
Because tadalafil treats both ED and the urinary symptoms of an enlarged prostate, it can address two concerns with one medication.
If your challenge is low desire or libido rather than blood flow, PT-141 works through a different pathway and may suit you better. And tadalafil should never be combined with nitrates, so if you take nitrate medications or have certain heart conditions, disclose them in your visit — a provider will determine whether it's safe for you.
You complete a private online visit, a licensed provider reviews it, and — if appropriate — your prescription ships to your door. No insurance required, no in-person appointment, no waiting room.
Answer a few private questions about your health and goals online — it takes just a few minutes, on your own time.
A provider licensed in your state reviews your information and, if appropriate, prescribes tadalafil at the right dose for you.
If prescribed, your tadalafil ships in unmarked packaging from a U.S. pharmacy to all 50 states. Automatic refills available, and you can message your care team anytime.
Pricing is shown at checkout — no insurance needed, no hidden fees.
You take tadalafil either as a low daily dose or as a higher dose about an hour before activity — your provider selects the approach and strength based on your health history and goals.
Taking tadalafil with nitrate medications (often prescribed for chest pain or heart conditions) can cause a dangerous, life-threatening drop in blood pressure. Tell your provider about every medication you take, and disclose any cardiovascular conditions or blood-pressure issues before starting.
Most side effects are mild and short-lived. Possible side effects include:
Start at the dose your provider recommends and don't take more than one dose per day. Seek immediate care for an erection lasting more than 4 hours (priapism) or for any sudden vision or hearing changes.
A side-by-side look at the erectile-dysfunction options available through ForbiddenRx. Your provider helps you choose what's right.
| Treatment | What it is | Onset | Duration | Form | Rx required |
|---|---|---|---|---|---|
| Tadalafil Popular | Generic Cialis®, a long-acting PDE5 inhibitor | 30–60 min | Up to 36 hours | Tablet | Yes |
| Sildenafil | Generic Viagra®, a PDE5 inhibitor | 30–60 min | 4–6 hours | Tablet | Yes |
| Vardenafil | Generic Levitra®, a PDE5 inhibitor | 30–60 min | 4–6 hours | Tablet | Yes |
| PT-141 | A peptide acting on desire and arousal | ~45 min | Varies | Injection | Yes |
The biggest difference is how long it lasts. Sildenafil (generic Viagra®) works for about 4–6 hours, while a single dose of tadalafil can last up to 36 hours — which is why it's known as the "weekend pill." Both are PDE5 inhibitors that work the same way and require natural arousal, but tadalafil gives you a far wider window of spontaneity. Tadalafil is also FDA-approved to treat the urinary symptoms of an enlarged prostate, which sildenafil is not.
Neither is universally "better" — it depends on your lifestyle. A low daily dose (2.5–5 mg) keeps tadalafil active in your system so you're always ready without planning, which many men prefer for spontaneity. A higher as-needed dose (10–20 mg), taken about an hour before activity, works well if intimacy is less frequent or more planned. Your provider recommends the approach that fits your goals and health history.
Most men find as-needed tadalafil begins working within 30–60 minutes, and some notice effects sooner. Unlike some ED medications, it isn't significantly slowed by food or a heavy meal. Natural sexual stimulation is still required for it to work. On the daily low dose, tadalafil stays active continuously, so there's no waiting period.
Tadalafil comes in 2.5 mg, 5 mg, 10 mg, and 20 mg. The lower strengths (2.5–5 mg) are typically used for daily dosing, while 10–20 mg are common for as-needed use. Your provider recommends a starting dose and schedule based on your intake form, and your plan can be adjusted over time based on how you respond.
Tadalafil should never be taken with nitrate medications (used for chest pain or certain heart conditions) — the combination can cause a dangerous drop in blood pressure. It may not be appropriate for men with certain cardiovascular conditions, very low or uncontrolled blood pressure, or those taking specific other medications. This is exactly what the provider review is for: disclose all your medications and conditions, and a licensed provider will determine whether tadalafil is safe for you.
No. There's no insurance required and no in-person appointment. You complete a short online visit, a licensed provider reviews your information, and if appropriate, tadalafil ships discreetly to your door. A prescription is not guaranteed and is subject to provider review of your health history.
U.S. board-certified clinicians
Dispensed by licensed U.S. partners
Nationwide telehealth coverage
Tadalafil's up-to-36-hour window is built around your life, not the other way around. Complete a private online visit and a licensed provider takes it from there.
Medically reviewed by ForbiddenRx Medical Affairs — Independent, licensed medical providers · Last reviewed July 2026. This page was written and is periodically reviewed for medical accuracy in line with clinical guidance followed by the independent, licensed medical providers in the ForbiddenRx network. It is provided for general educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk with a licensed provider about your individual health.
This page is educational and is not medical advice.