can you inject bpc 157 in the muscle BPC-157 Therapy Austin Oral vs Injectable BPC-157: Differences,

length-dependent (longest fibers affected first)

But its also the least safe, least effective, and most demanding type of B12

Labs Help, but Symptoms Still Matter When serum B12 improves but fatigue, tingling, focus changes, or sleep disruption continue, micronutrient testing can support a more precise form and dosing review

I also get pain in my right temple ( I wondered if it were to do with the piturity gland ) but wouldn't say I get it as bad as your experiencing mine is more of a dull ache

Relative telomere length and mitochondrial DNA copy number variation with age: association with plasma folate and vitamin B12. Mitochondrion 51 (2020): 79-87.