Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.   Wa alaikum assalam wa rahmatullahi wa barakatuh.   As to what follows:   In response to your question, we say:     Therapeutic injections whether they are administered on the muscles or veins are not nullifiers of fast according to the majority of the scholars.  Thus the fast is valid and does not need to be made up. This is the opinion that is held by most scholars and fatwas from fiqh and scholarly councils have expressed this opinion.