Is the lip biopsy a labial salivary gland biopsy? Is that possibly what they did? That doesn't sound like a biopsy for nerve density.

I had a muscle biopsy, that was deep....

Skin biopsy for nerve fiber density, which I also had, was done at 4 sites and was superficial, a punch biopsy similar to a mole removal. It was very easy compared to most of my procedures. They just clean the area, numb it and they do a punch. Mine was done at the medial area of the ankle, medially, just behind the knee, inner thigh and fore arm, near the elbow-medially. It is not anything to even worry about. My results took 6 weeks.

Lip biopsy for a salivary gland IS painful and does take a few weeks to heal. I had that done to. They look at those for Sjogren's and for Amyloidosis.