It's an irreversible loss that affects four in ten Irish men as well as Hollywood stars, millionaire footballers and the most powerful man in the world.
Each year, an estimated €1.63bn is spent worldwide on trying to halt, reverse or cure the condition.
But despite decades of research, frequently claimed breakthroughs and the fervent prayers of millions of men, science has so far failed to come up with a cure for male pattern baldness.
There have been many claimed "magic bullet" breakthroughs, including the recently developed class of drugs known as JAK Inhibitors, hailed as potential "game-changers" in the fight against several of the most common types of hair-loss.
JAK inhibitors (or JAKinhibs) can regulate the body's autoimmune system and have shown great promise in a wide range of medical conditions, from treating rheumatoid arthritis to combating certain cancers and plaque psoriasis.
But their startling effect on certain types of alopecia (hair loss) were discovered - as is so often the case in modern medicine - by accident.
A team of researchers at Yale University in the US began conducting trials of JAK Inhibitors on patients suffering from severe plaque psoriasis (a chronic autoimmune condition that causes patches of thick, scaly skin) in 2014.
One of the trial subjects was a 25-year-old male who, as well as suffering from psoriasis, had been completely bald since the age of 18 due to severe alopecia areata, a condition commonly known as "spot baldness".
The JAKinhibs did help with his psoriasis - but they had a totally unexpected and dramatic effect on the young man's almost total-body hair-loss.
Within three months of treatment with JAKinhibs, there was complete regrowth of the scalp hair along with regrowth of eyebrows, eyelashes, facial hair, and underarm hair.
Further trials and research have prompted excited talk of a "magic bullet cure" for baldness.
But many experts in the field are sceptical, pointing out that JAKinhibs seem to combat only specific types of alopecia and have not been proven to effect the most common (by far) cause of hair-loss, male pattern baldness.
Dr Maurice Collins is the founder and director of the HRBR Clinic in Blackrock, Dublin and one of Ireland's leading hair-transplant surgeons. His celebrity clients include Anton Du Beke of Strictly Come Dancing fame, Louis Walsh and actor James Nesbitt.
Dr Collins believes that talk of JAKinhibs as a miracle cure for male baldness may be a bit premature.
"It does seem that once a year or so, there's talk of some miracle breakthrough and you'll see headlines that we have finally found a cure for baldness," says Dr Collins.
"I remember when I decided to go into full-time hair transplant surgery more than 15 years ago, some of my colleagues were telling me not to bother because there would be a cure found any day. But as we know, that hasn't happened and while you can't predict what's going to happen in the future, I'm not convinced we are very close to finding a cure."
"JAK inhibitors have certainly benefited patients suffering from hair loss due to primarily dermatological reasons. But I would say that 97pc of the men I see have male pattern hair-loss and I believe these inhibitors have not been shown to have any effect on this, we would never use JAK inhibitors on male pattern baldness".
The HRBR Clinic does employ medical therapies as part of their treatments, including Minoxidil (also known as Regaine) and Finasteride (also known as Propecia). The latter is the drug taken by US President Donald Trump to combat his own hair-loss and there have been concerns over its side-effects which can, at certain levels and in a small percentage of patients, include loss of sexual drive, swelling of hands and feet and dizzy spells.
"You can find a lot of talk on the internet about potential side-effects of Finasteride," says Dr Collins.
"But our practical experience is that 98pc of men have no side-effects at all. And of the 2pc that do, the side-effects stop soon after they stop taking the drugs."
As one of the country's leading hair-transplant surgeons, Dr Collins is an advocate of the surgical route to combating hair-loss. And he says surgical methods have moved on greatly since the early days of unsightly "hair-plugs" in the 1980s.
But the surgeon says he understands why some men are fine with going thin (or even shiny) on top.
"Look, I always say, nobody has ever died from baldness. Nobody needs to treat it. But the men who come to us, they have many reasons for wanting to do so. And it's almost never simply vanity or image. In most cases, they'll tell us that they are doing it for the man they see in the mirror".
Jessica Kidd works with a range of hair-loss treatments at the JK Hair Replacement Clinic in Dublin, including prosthetic hair replacement systems (or what we used to call wigs).
These days, high-end wigs are based on mesh systems, which use real human hair, coloured and cut to match the person's natural hair and can stand up to anything from a vigorous gym session to a swim in the sea. Prices for a hair replacement system start at around €1,000 but can go significantly higher. With modern wigs, there are Fords and there are Ferraris.
"People may still think of the wigs they would have seen in the 1970s or 1980s, very heavy, unnatural looking, more like an item of clothing. The latest systems are nothing like that at all," says Jessica.
Their treatments also include laser-hair therapy, which combines drug therapy with low-level lasers to halt hair-loss and stimulate regrowth. A course of combined therapy can cost around €1,500 but the system claims a high success rate, especially when hair loss is tackled at an earlier stage in younger men.
When it comes to motivation, Jessica says her clients often talk about their self-image and self-worth, rather than how others see them.
"There are lots of different reasons for wanting to deal with hair loss. But mostly men talk about how they see themselves and who they want to be," says Jessica.
"If they are unhappy about losing their hair, especially if they are younger men, then they know they don't have to accept it, there are treatments and systems that will make a difference".
"And it's very different today to how it was. Men are taking care of themselves and how they look, they'll keep in shape, moisturise, eat well. Dealing with their hair-loss is not so much of a big deal now, it's just part of the package".
The range of treatments and therapies available to combat hair loss has increased dramatically in the past 10 years, from natural-look prosthetics to hair-thickening sprays and the transplants, which can cost between €10k and €20k.
The reasons why men feel compelled to take action on hair-loss also appear to have changed in recent years. Where once the main motivation may have been in conforming to an ideal of male sexual attractiveness, those working in the sector say their clients now talk about wanting to look young and virile in an increasingly competitive jobs market.
"We do have guys that come to us that feel that going thin on top is going to count against them in their careers," says Jessica Kidd.
"They worry that people will make negative judgements in a job interview, or how they are seen in the company they work for.
"We also get quite a lot of guys who are recently divorced or coming out of a long-term relationship, they are back out there on the scene and they want to make a positive change for themselves, almost in the same way a woman might get a new hairstyle after a break-up. They want a little confidence boost, to feel like they are ready to go out there again.
"And we have clients who go through a break-up and want to change everything about themselves, they go to the gym, start eating healthy, they get their teeth done, they get their hair done, and they'll often say; 'Why didn't I do this years ago when I was feeling miserable!'"
The good news for balding guys who want a complete make-over is that there have never been so many options, from the surgical, to drug therapy to hi-tech hair replacement systems.
The science has moved on exponentially since the days of the dreaded and painfully obvious "rugs" of the 1960s and 1970s.
But when it comes to the dream of all balding men, the "magic bullet" drug to finally cure male pattern baldness, it seems that the prospects are still thin.
The US Psychologist Thomas Cash has conducted some of the most extensive studies into baldness, how it affects the men who suffer from it, and how the rest of the world sees them.
And in a series of studies, Professor Cash has shown that, yes, bald men often have a poor self-image and modern western society has a bias against them.
After interviewing thousands of men suffering from hair loss, he concluded; "Men can feel that their attractiveness is diminishing and being bald worsens their chances for dating and mating."
In a study that looked at bias, Professor Cash showed people photographs of contrasting bald and hirsute men and (without mentioning their hair of lack of) asked them to rate the men for qualities such as self-assertiveness, social attractiveness, intelligence, life-success, personal likability, physical attractiveness and perceived age.
The result? Professor Cash found that; "The bald or balding models were perceived more negatively on every dimension except intelligence".
The study found that when people were shown photographs of bald men and asked to estimate how old they were, they added an average of three years and nine months to the men's actual age. Men with a full head of hair had an average of two years and five months taken off.