Causes of hair loss and/or thinning include:
Oxidative stress
Sun - Harmful UV rays
Emotional stress
Cosmetics, stretching, pulling etc 
Treatment options:
Hair supplements
Pharmaceutical medication - Finasteride, Minoxidil
Mesotherapy injections - Platelet rich protein and NCTF - Platelet Rich plasma contains Growth Factors that stimulate cell proliferation and differentiation. Your doctor access this valuable source of Growth factors form your body ! Hence there is no risk of rejection reactions occurring.  
Low Level Laser Treatment or LED treatment
Surgical hair transplants - follicular or strip
Mesotherapy treatment in practice:
Two vials of blood are drawn by your doctor in a sterile setting and the vials are spun in a centrifuge to separate the serum, Platelet Rich Plasma and the Platelet Poor Plasma.
PRP intradermal injections within scalp structures, followed by PRP mesotherapy technique on the superficial dermis
Followed 10 days later by NCTF intradermal injections    
Followed again 10 days later with a mesotherapy roller and NCTF only
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