Are you referring to https://pubmed.ncbi.nlm.nih.gov/34406358/ https://pubmed.ncbi.nlm.nih.gov/34406358/? The same amount was injected into the veins as into th

Are you referring to https://pubmed.ncbi.nlm.nih.gov/34406358/ https://pubmed.ncbi.nlm.nih.gov/34406358/? The same amount was injected into the veins as into the muscles, and the injections into the muscles were not found to cause myocarditis in the lab animals, while those into the veins were. Which at least suggests that a given quantity is more dangerous if injected into the blood than into the muscle.