Bald but beatuiful ... Vin Diesel in a scene from <i> Fast and the Furious. </i>

Bald but beatuiful ... Vin Diesel in a scene from Fast and the Furious.

It's a touchy subject.

No matter how common it is, hair loss strikes a nerve in many men — particularly those young enough to fear premature balding and those who pin much of their attraction on a full head of hair.

When pop star Justin Bieber, famed for his luxuriant hair almost as much as his voice, was interviewed last month in the British magazine Rollercoaster, he had some advice for Prince William when he discussed the Prince's thinning hair.

Billy Zane

Billy Zane Photo: ERIC GAILLARD

“I mean there are things to prevent that nowadays, like Propecia," he said. "I don't know why he does not get those things, those products. You just take Propecia and your hair grows back. Have you not got it over here?”

Justin, with his trademark locks, obviously assumed that everybody would like to fix their hair when they are balding. But Propecia may not be the answer.

The hair restoration medication, available in Australia, must be prescribed by a doctor. Finasteride (brand name Propecia) is a product manufactured by US pharmaceutical company Merck.

However, according to medical research, Propecia interferes with male hormones, including testosterone derivatives. Over the years, a vast number of men have reported experiencing unexplained sexual side effects, including impotence, erectile dysfunction, lower sex drive, infertility, testicular pain and genital shrinkage. Even when they stop using the drug, many of these men have reported that these side effects continue.

In a study published in the Journal of Sexual Medicine in July, Dr Michael Irwig, assistant professor of medicine at George Washington University, examined the long-term sexual effects experienced by a number of Propecia users.

The study involved 71 healthy men between the ages of 21 to 46 who suffered from sexual side effects lasting at least three months, despite stopping taking the medication.

Of these:

• 94 per cent developed low libido

• 92 per cent developed erectile dysfunction

• 92 per cent developed decreased arousal

• 69 per cent developed problems with orgasm

Dr Irwig states: “This is the first trial to show the medication can cause persistent sexual side-effects and the risk needs to be known when men are contemplating taking the medication and doctors are prescribing the medication.”

A second study by Dr Irwig, published on August 7 in the Journal of Clinical Psychiatry, showed that nearly 44 per cent of 61 young, healthy Propecia patients reported suicidal thoughts, while 36 per cent had symptoms of severe depression.

In Europe and the USA, some of the world's leading medical authorities and research institutions have warned that Propecia presents a danger to thousands of healthy young men. These research findings are backed up by Dr Irwig's studies.

Despite the alarming figures, just 2 to 4 per cent of the sample Propecia users encountered sexual side effects. Then again, the actual incidence might be much higher as many men may not have reported it because they were not aware of the side effects.

In Australia, Merck's patient information sheet clearly states the medicine's side effects — though, of course, not everybody looks at it.

The most common side effects of Propecia include:

1. Trouble getting or keeping an erection (impotence).

2. Decrease in sex drive that sometimes continues after stopping the medication.

3. Male infertility and/or poor quality of semen.

4. Breast tenderness and enlargement.

5. Changes in breasts, such as lumps, pain or nipple discharge.

6. Problems with ejaculation that continue after stopping medication.

7. Testicular pain.

8. Allergic rash, itching, hives and swelling of the lips.

As a clinical sex therapist, I have seen a small number of clients, only in their late-20s or 30s, who have come to me with unexplained loss of sexual desire. I now automatically ask if they are taking hair-loss products and I am not surprised when they answer "yes".

I advise them to stop taking the medication and, happily, none have reported the effects to be irreversible.

It's wise to re-think Propecia — and, if you or your man is using the drug and is experiencing side effects, consult your doctor.

Of course, other men may have second thoughts and try other means of keeping their hair.

But, I believe, Vin Diesel, Billy Zane and Bruce Willis look pretty good as completely bald as they are!