Here is a summary from a San Francisco area practice --> Dr. Victor Liu
There are 2 ways to augment the Girth of the penis:
1. By filler injection, which is good. As you probably know the fillers could be temporary or permanent. The results of the filler injection are very technique-dependent. You should consult an experienced doctor to have this done. I personally prefer the permanent fillers, and to obtain good proportions I augment the glans (head of penis) as well.
2. The other way is to insert a sheath that surrounds the shaft. This requires a minor surgery with minimal scar that can be easily concealed in the pubic hair or hidden at the junction of the scrotum and penis. If you want to have at least one Inch of Girth enlargement, this is probably the better way to do it. I personally use Surgimend which is made of purified and sterilized collagen. The glans will be augmented as well with fillers.
If you want more detailed information I will be happy to talk to you in person or virtually (Zoom).