Thanks for the query.
This is a common condition, and probably indicates a disturbed immune system.
You may be having a condition called alopecia areata, if there are well defined patches of hair loss. Other diagnosis may also be possible and can be ascertained while consulting. Treatment is simple and has different approaches. You need to discuss with a dermatologist to understand it.
Skin is the mirror of internal health and to get a perfect skin you need to treat both ways - internally and externally.
A healthy diet and lifestyle is mandatory to achieve results.
Usually 3 weeks is the gap between two injections.
Your dermatologist will decide a treatment plan for you after a consultation.
Apart from active pharmaceutical medicines, a healthy diet and lifestyle is mandatory to achieve results.