Naví Hair Solutions Men’s Hair Regrowth Treatment Extra Strength is for use only by men. Naví Hair Solutions Men’s Hair Regrowth Treatment Extra Strength may be appropriate for you if you are a male at least 18 years old and experiencing gradually thinning hair or gradual hair loss on the top of the scalp vertex only. It is not intended for frontal baldness or a receding hairline. The common inherited thinning or hair loss process begins slowly and may become noticeable only after years of gradual loss.