Arnica extract helps to rejuvenate the scalp and also to stimulate hair follicles, which in turn will strengthen the hair and keep it from falling out prematurely. Arnica extract may also help to prevent premature graying of the hair. Lemongrass is known to fight hair loss, treats oily hair, and cures scalp conditions. It is an antibacterial, so it keeps your scalp in a good condition for hair growth. Lemongrass is believed to strengthen hair follicles, which is essential for preventing hair loss.