Can smoking, or the contraceptive pill Yasmin cause my hair to start thinning?

Drugs can cause hair loss.  Sometimes birth control pills can cause hair loss.  However, it may not be the drug (birth control) that is causing the hair loss.  You need an examination to rule out other causes for hair loss.

Without seeing your scalp up close and learning more about your hair loss, it is not possible to comment on a cause. There are hundreds of reasons to lose hair.  Smoking can accelerate genetic hair loss a bit. Starting and stopping birth control pills are also associated with hair loss. Most oils, shampoosand dietary  measures have little, if any benefit.  

Yes smoking and contraceptive pills can cause hair thining ...because in smoking nicotine interferes with growth factors and contraceptive pills cause hormonal disturbances ....both the smoking and contraceptives pills can cause hair thinings ......for this THINING you need to have continuous sessions of PRP ( Platelet Rich Plasma ) in this procedure we inject PRP in to the Hair Roots with thin needles and as you know the platelets have growth factors in it which ultimately causes increased growth of Hair and increased volume of hair with in 90/120 days