Male pattern baldness refers to a loss of hair on the scalp in men. It happens as hormone levels change over a man's lifetime, and especially in the later years.
It is thought to affect 50 million men in the United States, and half of all men by the age of 50 years.
Although a natural part of the aging process for millions of men, hair loss can be psychologically distressing.
Sudden or unexpected hair loss can sometimes indicate a more serious health condition that may need medical attention.
Fast facts on male pattern baldness
Here are some key points about male pattern baldness. More detail is in the main article.
- Male pattern baldness, or androgenetic alopecia, typically occurs later in life as a result of changing hormone levels.
- Hair loss can be psychologically distressing for men, and they may seek a variety of treatments.
- Other causes of hair loss include nutritional deficiencies, infections, and some psychological conditions.
- Treatments include medications, laser and light therapies, and hair transplantation.
Men normally lose their hair when three main factors interact: genetics, age, and hormones.
Also known as androgenetic alopecia, male-pattern baldness happens as hormone levels change over the course of a man's life.
Genetic factors also affect the likelihood of male-pattern baldness.
These factors contribute to the gradual shrinkage of the tiny cavities in the skin at the base of hairs, known as scalp hair follicles. Hair grows progressively shorter and finer until no new hairs grow.
Most white men develop some degree of baldness, according to their age and genetic makeup. Male pattern baldness affects up to half of all white men by the age of 50 years and up to 80 percent of men in the same group by the age of 70 years. Other ethnic groups, such as Chinese and Japanese, are less affected.
Men with more first- and second-degree relatives who lose their hair have a higher chance of losing hair themselves.
Hair loss can also indicate a health condition, such as lupus, a fungal infection, or a thyroid problem.
Other possible causes include:
- Iron deficiency
- Excess vitamin A, possibly as a result of retinoid drugs
- Severe chronic illness, such as diabetes or lupus
- Use of anticoagulants, or blood thinners
- Telogen effluvium, a disturbance of the hair growth cycle
A number of genetic changes have been linked to male pattern baldness, but only one has been confirmed by research, the androgen receptor (AR) gene.
Other research has suggested that an abnormal quantity of a protein called prostaglandin D2 in the scalps of some men could link to hair loss.
Anyone who is concerned that hair loss may be a symptom of a health problem should see a doctor.
Many men see hair loss as a natural part of growing older, and they do not perceive the need for treatment.
However, hair loss can trigger negative psychological effects, such as low self-esteem. In some, it can contribute to depression.
Some treatments are available that may help reduce hair loss.
The U.S. Food and Drug Administration (FDA) has approved two types of drug treatment for male pattern baldness.
Minoxidil, or Rogaine, is a topical treatment applied to the scalp. It is available over the counter (OTC) at pharmacies, usually as a lotion or foam. It is reported to work best on the crown of the head.
Minoxidil was originally tested to treat blood pressure, but some people noticed additional hair growth as a side effect while using it. It is unclear exactly how it helps prevent hair loss.
It may take 3 to 6 months for results to appear, and the medication must be used indefinitely to preserve effects.
Adverse effects include skin problems, such as itching and irritation, hives, swelling, sensitivity, and contact dermatitis.
More rarely, the user may experience blurred vision, chest pain, a fast or irregular heartbeat, flushing, headache, lightheadedness, and numbness or tingling in the face or the extremities. Rapid weight gain may result.
Finasteride and dutasteride
Finasteride, or Propecia, is an oral treatment available only on prescription.
Finasteride is a 5-Alpha Reductase Inhibitor. It prevents dihydrotestosterone (DHT), a male hormone that plays a role in shrinking the scalp hair follicles. The drug blocks the formation of this hormone in the scalp, slowing the progression of baldness related to DHT.
The effects can take more than 6 months to appear. The 1 milligram (mg) tablet must usually be taken once a day for at least 3 months.
If the pill is stopped, the effects will be reversed.
In rare cases, finasteride can cause sexual dysfunction. This may include reduced libido, difficulty achieving an erection, and ejaculation disorders.
Other adverse effects include:
- breast tissue tenderness or enlargement
- skin rash
- swelling of the lips, tongue, or face
- abdominal pain
- back pain
Dutasteride is similar to Finasteride. It is also a 5-Alpha Reductase Inhibitor.
Two other treatments are available for male pattern baldness, both without prescription, in the form of shampoo:
- Ketoconazole 2 percent, also known as Nizoral
- Pyrithione zinc 1 percent, or Head and Shoulders
These are likely to be less effective than finasteride and minoxidil.
Hair transplantation involves taking hair from elsewhere and grafting it onto the scalp.
Hairs in the lower part of the back of the scalp are more resistant to androgens, and so they are used in surgical transplants. The hair donated to balding areas remains resistant to the male hormones.
Surgery involves either:
- taking a strip of skin from another part of the head, complete with hair, to graft it onto the bald area
- transplanting individual hairs, which avoids scarring
The procedures are expensive and unlikely to be covered by most insurance providers.
In a study published in 2013, scientists managed to grown new hair follicles in a lab, which produced some hairs when transplanted onto a mouse.
This is the only procedure so far that has grown new hairs.
This could one day lead to procedures that would enable new hair growth in men with male pattern baldness.
Laser and light therapies are popular, but they have not been shown to slow or prevent male pattern baldness, and the FDA has not approved them for efficacy.
A course of laser therapy may last from 6 to 12 months.
No use of vitamins or supplements has been confirmed safe or effective by the FDA.
However, as obesity, diabetes, and hypertension have been linked to hair loss, following a healthful diet, getting plenty of exercise, and avoiding excessive alcohol intake may help reduce the risk.
Not all men opt for treatment or even expect their hair to continue to grow naturally.
Some men will opt for a hairpiece or wig.
Other options include changing the hairstyle, shaving the head, or increasing facial hair. A good hairdresser will advise you about what suits you best.
You could just end up with a smart new look.