NORMAL HAIR LOSS
Normal hair growth occurs in a repeating cycle of growth, fall and replacement. At any one time, about 90 percent of scalp hair is actively growing (anagen phase). The other ten percent is either in the transition (catagen) phase or the resting (telogen) phase, waiting to be shed and replaced by a new hair in the next growth phase. One complete cycle of growth, fall and replacement takes from three to five years.
The scalp contains about 100,000 hairs, with slightly more for blondes and fewer for redheads. The average rate of normal hair loss is approximately 35 to 40 hairs per day. Although that’s a small number compared to the total number of hairs on the head, it can be alarming when found in a hairbrush or shower drain. Remember that normal hair loss is 35 to 40 hairs per day.
Hair that is in the catagen or telogen phase is not growing and is called bed-hair. Bed-hair is usually pulled out by brushing, combing or shampooing, but can remain in the follicle until it is pushed out by a new hair in the next growth phase. If a hair is pulled from the scalp, it takes about 130 days before a new hair emerges.
Scalp hair grows faster on women than men. Although individual hairs grow at a constant rate day or night, more falling hair is shed in the morning. Hair growth is also seasonal and reaches a peak in the summer with more falling hair in November.
ABNORMAL HAIR LOSS
Pregnancy disrupts the normal growth cycle of hair. Women usually have less hair loss during pregnancy, but experience sudden and excessive hair loss from three to nine months after delivery. Although this can be traumatic, the growth cycle returns to normal a few months after delivery.
Androgenetic alopecia, commonly called “male pattern baldness” is abnormal hair loss caused by age, genetics or hormonal changes. By age 35, almost 40 percent of both men and women show some hair loss from male pattern baldness.
Hair loss treatments that claim to make the hair appear thicker or fuller are classified as cosmetics because they claim to change the appearance of the hair. Changing the appearance of the hair is a cosmetic change.
The right shampoo, conditioner and styling aids are essential to anyone who wants to look their best, but even more important to those who suffer from hair loss. Hair loss creates a special set of needs that can be determined with a professional consultation and retail product recommendation.
Hair loss treatments that claim to make the hair grow thicker or fuller are classified as drugs because they claim to change the growth of the hair. Changing the growth of the hair is a physiological change.
Products that claim to grow hair fill the retail shelves and flood the internet and although we might like to believe the claims, Minoxidil (Rogaine) and Finasteride (Propecia) are the only two drugs approved by the FDA to treat androgenetic alopecia.
Minoxidil is a topical medication originally designed to lower blood pressure. Minoxidil is applied to the scalp twice a day, and although it’s greasy and inconvenient, it has been proven to stimulate hair growth. It is sold over the counter (OTC), as a non-prescription drug under the brand name Rogaine. Rogaine is available for both men and women in a 2 percent regular strength and a 5 percent extra strength version. It is not known to have any side effects.
Hair growth is controlled by androgens. Androgenetic alopecia is usually caused by dihydrotestosterone (DHT) that is converted to testosterone by the enzyme 5-alpha-reductase. At sexual maturity, DHT causes the baby (vellus) pubic hair in males and females to be converted to longer, thicker and darker terminal hair. DHT also causes the facial hair of males to be converted to the longer, thicker, darker terminal hair we know as a beard.
Ironically, in androgenetic alopecia that occurs later in life, the same DHT causes the miniaturization of the terminal hair on the scalp converting it to vellus hair. At the same time, DHT stimulates the vellus hair on the rest of the body to become terminal hair that grows in thicker, longer and darker, especially on the upper arms and back.
Finasteride is an oral, prescription drug for men only sold under the brand name Propeca. Finasteride inhibits the production of 5-alpha-reductase, the enzyme that reacts with DHT to cause male pattern baldness. Although Finasteride is more effective and convenient than Minoxidil, possible side effects include weight gain and loss of sexual function. These drugs are available for men only and only by prescription. Women may not use this treatment, and pregnant women or those who might become pregnant are cautioned not to touch the drug because of the strong potential for birth defects.
LOW LEVEL LASER THERAPY
Low level laser therapy (LLLT) is also called red light therapy, cold laser, soft laser, biostimulation and photobiomodulation. Low level laser therapy diodes emit either red light in wavelengths from 630 to 670 nanometers or infrared radiation. In the last ten years, the Federal Drug Administration (FDA) has granted premarket approval to several low level laser therapy devices marketed to consumers for home use. These devices are available as hard and soft head caps, as well as, hand held brushes and large combs.
Although the FDA regulates low level laser therapy devices, FDA approval does not mean that a product is safe or effective. The FDA clears medical devices for marketing as long as they are substantially similar to a product already on the market.
Physicians have mixed opinions on whether or not low level laser therapy is effective. While some completely reject its effectiveness, others believe that low level laser therapy can provide benefit for some men and women. Company trials have been criticized as biased and can’t be relied upon because they are not independent. Individual consumer reports on effectiveness are disappointing.
Additional information about hair loss can be found on the American Academy of Dermatology web site: https://www.aad.org/public/skin-hair-nails
And the FDA website: https://www.fda.gov/