From what I can gather (having read every progress report with dermal fillers for nearly the past 10 years), those who do say they have sensitivity loss, it's seldom to the point of "numbness" and often times subtle. Obviously, there are exceptions like how member New1Inch lost more shaft sensitivity than he preferred, but this is not typical of
Dermal Filler injections in general.
I honestly, GENUINELY cannot tell if I lost sensitivity, or if it's all in my head since others have reported it, but if I did in-fact lose some, it was probably 10% or so? Ironically, being thicker creates more friction, which offsets any loss in sensation I had after the procedure, so in the end it worked out for me.
Also, there are guys that report no change, and others who report even more sensitivity due to a wider surface area of the skin (these reports vary from
HA, to
PMMA, to Fat).
I can say confidentially that the risk of losing significant amount of sensation is RARE, assuming you're being treated by an experienced practitioner using medical-grade product.