Hi. Greetings. low testosterone levels and associated lack of secondary sexual development can cause low facial hair in men. But don't worry, I'd everything else is normal, low facial hair more commonly could occur due to genetic and hereditary factors and hair may be sparse in some men with normal testosterone levels. Minoxidil lotion and other peptide lotions may be worth a try to improve facial hair. Hair transplantation on face may be of ultimate curative value. Hope this helps. Warm regards, Dr Govind S Mittal.