Minoxidil promotes hair growth by increasing the duration of anagen, shortening telogen, and enlarging miniaturized follicles. See the video below for further explanation of the four phases of hair growth.
In randomized trial of 393 men with male pattern baldness (androgenetic alopecia) the men were randomized to 5%, 2% or placebo. After 48 weeks of treatment, 5% minoxidil was significantly better than the 2% solution or placebo (increase in count 18.6, 12.7 and 3.9 cm^2.
Response to treatment is variable, but according to one study the cosmetically significant improvement occurs in up to 30% of patients.
Side effects appear infrequent, and include contact dermatitis, irritant dermatitis, and rarely it can alter blood pressure, pulse rate, or body weight when systemically absorbed, though the amount absorbed through a scalp without defects is minimal.
“Minoxidil solution and foam are used to help hair growth in the treatment of male pattern baldness. It is not used for baldness at the front of the scalp or receding hairline in men. The foam and 2 percent minoxidil solution is also used to help hair growth in women with thinning hair.” – WebMD
Minoxidil is a non-surgical treatment for hair loss, but can also be used in conjunction with other hair loss procedures.
STAGES OF THE HAIR LIFE CYCLE
This video covers the four phases of the hair growth cycle in detail and explains what to expect in each. We shed hairs on a regular basis as many as 50-100 per day so it should come as no surprise that despite being intrinsically dead, hair has a life cycle. – courtesy of “Adam Explains”
Finasteride is an oral inhibitor of dihydrotestosterone (DHT) that is efficacious and FDA approved for male pattern hair loss. At a dose of 1 mg/day finasteride lowers serum and scalp DHT levels by more than 60 percent.
In studies, after 6-12 months of treatment, hair counts were 9 percent higher among patients treated with finasteride compared to placebo, and 24% at 48 months. Side Effects: Occasionally finasteride has deleterious effects on sexual function including erectile dysfunction, decreased libido, and ejaculatory function. However, this being the most feared side effect, it is still rare, as shown through 9 systematic reviews with a total of 3570 men, only 1.5 percent absolute increase in sexual dysfunction was noted.
Finasteride inhibits DHT. Click the link to read the NCBI Study: Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study Group.