USA products vs. Canadian. Such as Juvederm, Botox, etc. Filler lasted me 1 to 1-1/2 years. Is this possible?

The duration of a filler's effect depends on which filler is chosen. Some fillers are permanent, some last years and some last months. 
The most common fillers are made from hyaluronic acid (HA); these are broken down by a specific enzyme in our body so the duration of effect depends on:
1. The number of bonds and/or the size of the HA molecules in a particular filler: Not surprisingly, more bonds and/or larger molecules take longer to break down. Sometimes my patients will ask me to use a long lasting filler in a specific location (for example Voluma in the lips); however, filler must be selected based on the location it will be injected. In this example, if Voluma is placed in the lips, the result would be unattractive because the Voluma's consistency is too stiff for that location. 
2. The level and quality of the enzyme that breaks down HA in a particular person (hyaluronodase or HAase): There is a natural variation in hyaluronodase level and efficacy from person to person. Some people make more, some people have slight structural variation that make their enzyme work better than another person's enzyme.
3. The location that the filler is injected: For example, the earlobes don't move very much and don't have a great blood supply. It seems like filler lasts years in this location. I have a patient whose ear lobes I injected with a hyaluronic acid filler 7 years ago and they still look terrific. On the other hand, the lips are very vascular (have a good blood supply) and move a lot. The same filler that has lasted 7 years in my patient's earlobes lasts an average of 9 months in the lips.
4. The volume of filler injected: The reason why volume matters is that the enzyme (HAase) can only chisel away at the surface of a clump of filler while the inside (volume) is protected. As an object (or clump of filler) gets larger, it has less surface area in relation tovolume. To understand this, it may help to consider how easily babies get cold compared to adults. A baby has more surface area compared to its volume than an adult so babies loose heat more quickly and are at greater risk of becoming dangerously cold. Applying this principle to fillers means that a little bit of filler will be eroded more quickly than a large cluster of filler. Two syringes injected in one location last longer than one syringe in the same location.
Patient often think that doctors can control how long a filler lasts. Unfortunately this is not true; the determining factors are the patient's choice of filler, the choice of location, how much they want or can afford and factors inside the patient's body. Of course, your doctor should be educating you so that you can make an informed choice. You should know the name of the filler you receive, the filler's average lifetime and the volume you receive. Like many things in life, you get what you pay for. In your case, the low cost you paid did not include an adequate explanation of what you were getting.
I am concerned that you mentioned Canada in your question given that you live in Arizona. If you travel to Canada and get injections there, that's fine. The same filler made by the same manufacturer should have the same properties and be as safe as that filler in the US. The problem is that it is illegal for a physician to import drugs from other countries. A physician who is willing to break this law, may also be willing to cut corners on other aspects of medical treatment.

It will depend on a few variables: the type of filler, how much was used and the area injected. Botox results resolve in 3-4 months, however filler results can vary from 6 - 18 months depending on the type used. I recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer

Always be sure to know which filler you are having injected.  Allergan makes several different fillers that are FDA approved, all with different longevities.  Voluma: upto 2 years; Vollure: up to 1 and 1/2 years; Volbella, Ultra and UltraPlus: up to 1 year.  Other products may have FDA approval for only 6 months.  The way the product was injected can make a difference as well so you want to go to a well trained medical professional who obtains their fillers directly from the company (not imported from a foreign pharmacy, which is illegal and risky).  Fillers will last different amounts of time depending on where on the face they are injected as well. 

Juvederm has a whole family of product versions, depending on the size of the hyaluronic acid (HA) molecules, the consistency of the gel, the cross-linking between molecules, etc. These determine the stiffness of the product and how long it lasts, which in turn are factors influencing where the provider is likely to inject the product. The longevity of a product is not determined by the person injecting it - it is more dependent on the patient's biology and how fast the patient metabolizes the product. Importing of medical products like fillers is not allowed but I have seen facilities that do it - they believe the active ingredient is the same and an equivalent Allergan Juvederm product sold in another country should perform the same way as one FDA-approved for sale in the US. While that may be true, technically, it represents a decision made based on profit-motive rather than ethically providing care to the patient.

Thanks for your question. You need to compare apples to apples.  Different fillers "last" for different amounts of time, and can also vary somewhat from patient to patient.  The duration of effect can vary from 6 months up to even 24 months.  The most important thing to concentrate on is finding a well trained and experienced physician injector who can guide you through your filler choices, and give you the best chance at a good outcome. Focus on that.  Best of luck to you!

The most important question is, was the same product being used? Different fillers have different longevity. Good luck for New York City

There is likely a good reason that the cheapest product doesn't last as long. The longer-lasting fillers typically cost more than those that do not last. Makes sense - the cross-linking technology leading to long-term results is expensive. It helps to know precisely which product you are receiving and by whom... You can shop around for the cheapest syringe, but you can't always put a price tag on the expertise of the injector. Judgment, technique, and experience of aesthetic physicians might cost a bit more than a technician. Best wishes.