Most erectile dysfunction tablets give you a window of a few hours — tadalafil gives you up to 36 hours of coverage. That’s why tadalafil suits some people better than the alternatives, and it’s the reason it can be taken either shortly before sex or in a smaller dose every day.
The original brand name for tadalafil is Cialis. In Canada, you’ll also find generics like Apo-Tadalafil, Teva-Tadalafil, or Jamp-Tadalafil. They’re all the same medicine, and all require a prescription.
In this article, we cover how tadalafil works, how long it lasts, and the difference between taking it daily and before sex. We also look at side effects, what Cialis and generic tadalafil cost, and how to get a prescription online from a Canadian-registered doctor.
An Overview of Tadalafil and Cialis
Tadalafil is a prescription tablet for erectile dysfunction (ED). It’s one of a small group of oral medicines called PDE5 inhibitors that Health Canada has approved for treating ED. PDE5 inhibitors work by relaxing the smooth muscle in the blood vessels supplying the penis so more blood can flow in during arousal. In practice, that means tadalafil usually makes it easier to get and keep an erection.
Cialis is the brand name Eli Lilly has sold tadalafil under in Canada since 2003. Generic versions arrived in July 2016, and around twenty manufacturers now hold Canadian approvals. Branded and generic tadalafil and Cialis tablets contain the same active ingredient at the same strength. Because Health Canada requires every generic to be shown bioequivalent to the original before it can be sold, the practical difference between brand and generic is price, not effect.
Tadalafil comes in four strengths in Canada — 2.5 mg, 5 mg, 10 mg and 20 mg. Which one you’re prescribed usually depends on whether you’ll take tadalafil before sex or every day. In most cases, higher doses are used before sex, while lower doses are taken every day. Health Canada has also approved tadalafil for the urinary symptoms of an enlarged prostate.
How Tadalafil Works
Tadalafil works by protecting a chemical signal your body already makes during arousal.
When someone is sexually aroused, nerves in the penis release nitric oxide, which switches on an enzyme called guanylyl cyclase, and that raises levels of a messenger chemical known as cGMP. Rising cGMP relaxes the smooth muscle in the penis, blood flows in, and an erection follows.
An enzyme called PDE5 breaks cGMP down again, which is how an erection normally subsides. Tadalafil blocks PDE5, causing cGMP to stay higher for longer, and an erection becomes easier to reach and to hold.
One useful thing to know before taking tadalafil is that it needs arousal to do anything. Eli Lilly’s Canadian product information explains that tadalafil has no effect on blood flow to the penis without sexual stimulation. Arousal comes first, and the tablet supports what your body is already doing.
How Long Does Tadalafil Last?
Tadalafil usually starts working within about 30 minutes, peaks in the blood at around two hours, and can still work up to 36 hours after a dose. That long window is what sets tadalafil apart from the other ED tablets, which typically are active for about four hours. The long duration of tadalafil comes from its 17.5-hour half-life.
The 36-hour figure is easily misread. Those 36 hours aren’t how long you might have an erection — they’re a window of increased responsiveness. The number comes from trials where men attempted sex 24 or 36 hours after a single dose. It’s worth noting that not everyone who takes tadalafil responds for the full 36 hours.
A few practical points on tadalafil:
- Food doesn’t reduce effectiveness. Tadalafil is absorbed the same way with or without a meal.
- Alcohol can cause issues. Tadalafil and alcohol both widen blood vessels, so a heavy night alongside a dose can leave you light-headed when you stand up.
- Timing may take time to get right. The Canadian product information suggests having sex at different points after a dose to find your own best window.
If you’re weighing tadalafil’s long window against a shorter-acting option, we compare the two in our Cialis vs Viagra article.
How to Take Tadalafil: Daily or As Needed
Tadalafil is prescribed for both on-demand and daily use. Health Canada labels the tadalafil 10 mg and tadalafil 20 mg tablets for on-demand use, and the 2.5 mg and 5 mg tablets for once-a-day use. Cialis dosage and generic tadalafil dosage are identical because they are the same drug at the same strengths.
Tadalafil Dosage for On-Demand Use
The recommended Canadian dose for on-demand tadalafil is 20 mg, taken before you expect to have sex, with or without food. Your doctor can adjust that up or down depending on how well it works and how you tolerate it, but the maximum dose of tadalafil in 24 hours is a single tablet.
One thing worth knowing if you’re reading American sources: US labelling starts at 10 mg, so the numbers you see online often differ from the Canadian recommendation.
Tadalafil and Cialis Pill Dosage for Daily Use
The daily approach for tadalafil uses a much lower dose — 5 mg once a day, taken at roughly the same time, and reduced to 2.5 mg if that suits you better. Levels build up over about five days, after which tadalafil is always present in your system. Taking tadalafil daily tends to suit people having sex twice a week or more, or anyone who’d rather not think about timing at all.
If the first attempt disappoints, that doesn’t necessarily mean the medication isn’t right for you. Canadian urology guidance recommends discussing how tadalafil is being taken with your doctor and adjusting the dose or timing if needed.
Tadalafil and Cialis Side Effects
Most people who take tadalafil either experience no side effects or only get mild issues that settle on their own. Cialis side effects are the same as generic tadalafil side effects, because the medicine is identical.
In the Canadian trials, the most common tadalafil side effects were:
- Headache (11%)
- Indigestion (7%)
- Back pain (4%)
- Muscle aches (4%)
- Nasal congestion (4%)
- Flushing (4%)
- Dizziness (about 2%)
Back pain and muscle aches are more common with tadalafil than with the shorter-acting ED tablets. They usually appear 12 to 24 hours after a dose and settle within about two days. Why tadalafil does this is not fully understood.
Few people stop taking tadalafil because of side effects. In the Canadian trials, under 2% ceased treatment.
Serious Tadalafil Side Effects
Serious reactions to tadalafil and Cialis are rare, but three are worth recognising:
- Sudden loss or blurring of vision in one or both eyes has been reported with PDE5 inhibitors, linked to a condition affecting blood flow to the optic nerve (anyone who has had it before shouldn’t take tadalafil).
- Sudden hearing loss, sometimes alongside ringing in the ears or dizziness, has been reported rarely.
- An erection lasting more than four hours needs emergency care, because a prolonged erection can cause lasting damage to the penis.
In all three cases, stop taking tadalafil and get medical attention quickly rather than waiting to see whether the problem passes.
Who Shouldn’t Take Tadalafil
Tadalafil on its own barely lowers blood pressure in healthy people. However, it interacts with some older blood-pressure medicines, doxazosin in particular, where the combination can leave people light-headed on standing.
Medicines containing nitrates — commonly prescribed for angina, and including recreational “poppers” — combine with tadalafil to drop blood pressure to dangerous levels. If a nitrate ever becomes medically necessary, speak to your doctor about whether it’s still safe to take tadalafil.
Tadalafil also isn’t recommended for men whose heart condition makes sex itself inadvisable. A recent heart attack, unstable angina, an uncontrolled arrhythmia, or blood pressure that’s very low or poorly controlled might mean it isn’t suitable. A doctor checks for all of that before prescribing tadalafil.
What Cialis and Generic Tadalafil Cost in Canada
Tadalafil is bought by the tablet. On-demand packs come in twos, fours, and eights, while the daily strengths come in packs of 14 or 28. What you spend overall depends largely on how often you actually use it.
Why Is Cialis So Expensive in Canada?
Brand-name Cialis is expensive, but tadalafil itself is reasonably affordable now. Cialis had the Canadian market to itself for thirteen years, but generic tadalafil arrived in July 2016, and around twenty manufacturers now compete for the same prescriptions, which has lowered the price. Brand Cialis is still on the market, but most Canadians are now dispensed generic Cialis.
What You’ll Actually Pay
Public formulary prices give the clearest picture of cialis and tadalifil cost. In Ontario, generic tadalafil 5 mg (the daily strength) runs roughly $3.65 to $3.90 a tablet, while the 10 mg and 20 mg on-demand strengths cost around $12 each. Someone on the daily tablet buys about thirty at a time, while a person using tadalafil occasionally might only buy four. Formulary figures aren’t what you’ll pay at the till, and retail prices vary between pharmacies.
Is Cialis Covered by Insurance?
ED medication is one of the more common exclusions from public drug plans. In BC, PharmaCare covers tadalafil only for pulmonary arterial hypertension under Special Authority — not for erectile dysfunction — so most people in BC pay out of pocket. Private and workplace plans vary: some cover ED medication, many exclude it or cap how many tablets a year, so it’s always worth checking.
Getting a Tadalafil or Cialis Prescription in Canada
Erectile dysfunction treatment in Canada starts with a prescription, and getting one for tadalafil doesn’t need an in-person visit. Erectile dysfunction is diagnosed mainly from your history rather than a physical examination, which makes it well suited to an online doctor’s appointment.
An appointment about ED usually involves a discussion about what you’ve been experiencing and for how long, and a review of your general health and medications. If tadalafil is appropriate, the doctor can issue a prescription.
In British Columbia, an appointment with a Walk In doctor is covered by MSP, so the consultation itself costs nothing. Appointments are available across the province, Vancouver included, and you can book one the same day.
What About Overseas Pharmacies?
Buying tadalafil online from an overseas pharmacy is a different matter. Canadian residents generally can’t legally import prescription medicines by mail, and Health Canada has warned about counterfeit Cialis and about “natural” enhancement products found to contain undeclared tadalafil or sildenafil. Buying tadalafil in Canada through a licensed pharmacy, on a prescription, is the only way to be sure what you’re taking.
Frequently Asked Questions About Tadalafil
Is Apo-Tadalafil the same as Cialis?
Apo-Tadalafil is Apotex’s version of the same medicine, and Teva-Tadalafil, Jamp-Tadalafil, and Auro-Tadalafil are other companies’ versions. All contain tadalafil at the same strengths, and Health Canada requires each to be proven equivalent to Cialis before sale.
Does tadalafil make you last longer?
Tadalafil treats erectile dysfunction by improving blood flow, so it helps you get and keep an erection. It isn’t approved for premature ejaculation and doesn’t reliably delay it. Some men do find sex lasts longer simply because the erection is firmer, but that’s a side effect of treating the erection, not what tadalafil is for.
Can women take Cialis or tadalafil?
Health Canada hasn’t approved tadalafil for women, and the Canadian product information says so directly. The same molecule is used in women for pulmonary arterial hypertension, but that’s a different product for a different condition.
How long does tadalafil stay in your system?
With a half-life of about 17.5 hours, tadalafil is largely cleared in four to five days. That’s why at least 48 hours should pass before any nitrate is given, and why the daily tablet takes about five days to reach full effect.
How do you get the most out of tadalafil?
Arousal still has to be there — tadalafil supports it rather than replacing it. You might like to try an on-demand dose at least 30 minutes before sex, and try different timings across the window to find what works best. Go easy on alcohol, and treat the first attempt as a starting point rather than a final verdict of whether tadalafil works for you.
Is Tadalafil Right for You?
Tadalafil suits a lot of men with erectile dysfunction, and its long window makes it more flexible than the shorter-acting ED medications. Whether it’s the right choice depends on your general health, the other medicines you take, and how often you’d expect to use it.
If you are having trouble getting and maintaining an erection, a doctor from Walk In can help you work out what’s behind it and discuss suitable treatment options.
Speak to a Doctor Online About Erectile Dysfunction Treatment
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