Being given medicine via injection does not break the fast, whether it is intramuscular or intravenous, so long as the injected substance does not provide nutrition.

If the face mask made of honey entered your mouth and you tasted it without swallowing, that does not affect your fast.

If the fasting person detects the taste of blood in his throat that does not affect him even if he swallows it, but if it comes up to the mouth then he swallows it, he breaks his fast.

If your period begins before sunset, even if it is a moment before iftar, your fast is invalidated and you have to make up that day.

If you do not wear hijab, then you are disobeying your Lord thereby, but your fast is still valid. Sins, including not wearing hijab, do not invalidate the fast, but they detract from its reward, and may cause it to be lost altogether.

Cursing does not break your fast but it does detract from your reward.

Masturbation breaks the fast and the one who does that has to make up for the day that he broke his fast. He must also repent from this great sin.