Trump's doctor reveals the secret behind his hair

Donald Trump hair drug US president
Donald Trump's personal doctor of 36 years said the president takes a prostate-related drug to promote hair growth. (Getty)

Donald Trump's long-time doctor has revealed the US president takes medication for three ailments, including a prostate-related drug to promote hair growth. 

Dr. Harold N. Bornstein says that as well as taking hair-growth drugs, his most famous client also requires regular antibiotics to control rosacea, a common skin problem, and a statin for elevated blood cholesterol and lipids.

Mr Trump takes a small dose of the drug, finasteride, which lowers PSA levels and is marketed as Propecia to treat male pattern baldness. It's the reason why he has shoulder length hair, Dr Bornstein told The New York Times. 

Dr. Harold Bornstein personal physician Donald Trump
Dr. Harold Bornstein, personal physician to Donald Trump. (Getty)

Dr Bornstein has been Mr Trump's personal doctor for 36 years. He also took part in the presidential campaign in December 2015, when Mr Trump published a doctor's letter from him that declared that the Republican nominee would be the "healthiest individual elected to the presidency".

Despite Mr Trump being the oldest president in history at 70-years old, his long-time doctor stands by his statement, telling the newspaper his medical care was up to date. 

Dr Bornstein, 69, has a private practice on the Upper East Side of New York and has been overseeing Mr Trump's medical care since 1980 up until his presidency. 

Former president Ronald Reagan, who took the oath of office in 1981, was the second oldest president at 69. 

Mr Trump's father, Fred, suffered from Alzheimer's disease in his 80s and a number of experts have urged that older political leaders undergo such tests.