The most common cause of post-injection pain (PIP) is the skin or immune system's reaction to the needle or the compounds BB% (benzyl benzoate) or BA% (benzyl alcohol). Less common causes include an allergic reaction to the medication. In rare cases, an infection at the injection site can occur. Additionally, the type of oil used can contribute to irritation. The amount your underground lab utilizes of BB or BA can also lead to skin irritation that results in PIP.
My advice is to use different injection sites, such as the deltoids or glutes, to avoid discomfort in future injections. please use deferent location Deltoids or Glutes to any future discomfort site injection