botox that lasts

For those of you who saw my earlier posts, I had a facelift, necklift and lip lift with dermal grafts by Dr. Mardirossian. I am still very, very happy with the results.. 8 months now. So... yesterday I visited to discuss ear lobe shortening and will look forward to doing this in the near future.
While there I had botox in the forehead, between the eyebrows and at the crows feet. I'm not sure why but his botox injections are longer lasting than any others I've had (have had maybe 4-5 injections over the past 10 yrs) and his placements are superb giving me the exact refreshed look I like without looking "botoxed" . The price is higher but since it lasts longer on me I can justify it.