According to a new study, Finasteride, a widely-used drug that reduces the size of prostate glands and stimulates hair growth, also affecting the president's low PSA (prostate) levels and thick mane.
That is not all, it has been tied to several other sever and uncomfortable side effects as well.
According to a research paper published in May 2017, it showed concrete evidence regarding the pills’ mental health risks and appeared to confirm many medic’s fears that it increases risk of suicidal tendencies. The study was conducted by Western University in Ontario.
Another study conducted by the Northwestern University Feinberg School of Medicine found most study participants being left impotent for four years after taking Propecia.
Finasteride belongs to a class of medications known as 5-alpha-reductase inhibitors (5ARIs).
Finasteride was originally developed to treat urinary problems in men, but studies went on to show the drug made prostate glands smaller by reducing levels of hormone dihydrotestosterone in participants.
But during the clinical trials, scientists saw an unexpected side effect - hair growth, prompting, in 1997, the FDA to approve the steroid inhibitor as the first ever drug to treat male pattern baldness.
In an interview given to New York Times, Bornstein said that he, too, takes the drug, saying it helped him keep his shoulder-length locks and helped Trump keep his own hair.
The doctor said: 'He has all his hair. I have all my hair.'
The news that Trump takes finasteride explained why his PSA (prostate specific antigen, produced for the cells by the prostate) is so low.
Finasteride reduces PSA levels to reduce swelling of prostate glands.
While men aged 60-69 normally have between 4.0 and 5.0ng/ml, Trump's PSA level was 0.15, Bornstein said in two letters he'd written about Trump's health. The first letter came out in December 2015, followed by the other letter in September 2016.
The level prompted urologists - who weren't linked to Trump - to say he had to have received care for an enlarged prostate or prostate cancer.
Bornstein told the Times that the commander-in-chief hasn't had an enlarged prostate nor prostate cancer, and attributed Trump's PSA level to Propecia.
Lead author of the study at Western University, Dr Blayne Welk said that there aren’t a lot of good studies in this area, and it's a very common medication for urologists to use.
Welk's team analysed data from 93,197 men who were at least 66 years old when they received prescriptions for 5ARIs between 2003 and 2013, plus another 93,197 similar men who had never filled a prescription for a 5ARI.
The research found men in the 5ARI as having 94 per cent higher risk of depression in the first 18 months, compared to men not using these drugs. Beyond 18 months, the increased risk of depression fell to 22 percent.
The type of 5ARI did not appear to significantly alter the results.
Welk cautions that the actual risk of depression and self-harm is very low.
A separate study in the journal PeerJ evaluated another concern about 5ARIs - erectile dysfunction.
Drs Tina Kiguradze and William Temps of Northwestern University Feinberg School of Medicine in Chicago and colleagues found that when erectile dysfunction occurred in men taking 5ARIs for at least 180 days, the dysfunction was more likely to last at least 90 days after stopping the medication.