symptoms worse after b12 injections Side Effects of Injection (Common and Serious) Are B12 Shots Safe? Royal
Description
While some users report feeling more sustained energy within the first two weeks, more noticeable changes in body composition and weight often appear after about 12 weeks of consistent use

Identification and importance of brown adipose tissue in adult humans

I should know

The actual injection takes only a few seconds, and any discomfort is typically minimal and brief

Thats fine too
(2001) demonstrated that AOD-9604 in isolated rat adipocytes increases lipolysis by ~150 % over baseline, comparable to full hGH stimulation, but without any effect on cellular proliferation
