Do sculptra injections have to be timed close together in order to be effective? I had 2 vials four months ago.

First of all, I am a big fan of Sculptra.  However, for Sculptra to produce a satisfying result and for a patient to be satisfied requires an understanding of the product.  Sculptra adds facial volume gradually over 4-6 weeks, typically calling for 2-3 treatments to achieve the desired end point. A slightly underweight 42 year old woman who has indications for Sculptra is guaranteed to be underwhelmed after one treatment session.  When I see patients of your description, I inform them that Sculptra requires a commitment to several treatments.  If a patient is not willing to accept this plan, it is probably best not to have the treatment.  I would consider a return visit to your Facial Plastic Surgeon or Dermatologist with this information in mind.

It is best to have a series of treatment spaced 1 to 3 months apart, but you should still see a better responsewith the second treatment than you had with the first if you do it now. I would plan one treatment now, then another in 4 to 6 weeks.

Sculptra
Aesthetic is used to correct shallow to deep facial wrinkles and folds, it is
specifically designed to stimulate natural collagen growth over an extended
period of time with multiple sessions. Sculptra’s collagen improvement
continues for 6 months after your last session. Once you are done with your
Sculptra treatment sessions the results can last up to 2 years.

In my office
I generally recommend 3-4 vials about 4-6 weeks apart. This allows for gradual
improvement that is long lasting, if my patient can’t follow this
recommendation because of time constraints or financial reasons then there are more
immediate fillers that can be used.

If you would
like to continue with Sculptra then I would recommend spacing your treatments
4-6 weeks apart and consulting with a Board Certified Dermatologist with plenty
of experience injecting Sculptra.

Typical, after the first session of Sculptra, there is not much change seen.  It's really seen after the 2nd treatment session.  It is standard to have the sessions about 6 weeks apart because at that time, most of the collagen that is to be stimulated is present, so the physician can see how much more needs to be done.  Waiting longer has no negative consequence.  If the doctor knows that you require a lot of volume, sometimes waiting only 4 weeks after the first session can be done.  

You are under the WRONG impression about "sculptra". It is a collagen stimulator NOT a volume filler like HA's. Thus you would need every 3 weeks for 4 to 6 months injections before a result would have produced an effect. I session in 4 months was a waste of $$s... 

Sculptra is a fantastic product, especially if you are under weight and need to add volume to your face.  If you only had one injection 4 months ago you will not have the desired results.  It generally takes three injections spaced a month a part to have enough Sculptra to add the volume that you need if you are under weight.  I would return to your treating physician to finish the sessions.  Once you are done, the results last at least two years.  Please find a board certified physician with a great deal of experience with cosmetic dermatology for the best results.