Biotin 10mcg supplements are commonly prescribed to improve hair fall, is it really effective and does the body really need an external biotin source?
Biotin or vitamin B7 is a very common vitamin. It is widely available in all kinds of foods and what is more important intestinal bacteria produces biotin. As so true, acquired deficiency of biotin in modern world is practically non-existent (Wikipedia).
There are however some genetic mutations which can lead to biotin deficiency (Wikipedia). One of the prominent symptoms of inborn biotin deficiency is alopecia or hair loss. Due to this biotin supplements are often marketed as a treatment for hair loss.
A recent review in a high quality dermatology journal recaps the current treatments for male and female hair loss (PubMed). Authors conclude that "No clinical trials showing efficacy treating hair loss; in vitro studies show no influence of biotin on cultured human follicular keratinocytes".
I would not waste my money on biotin supplement due to the very negligible likelihood of biotin deficiency causing hair loss.