Finasteride is a 5α-reductase inhibitor drug. Its initial intended use was as a treatment for prostate growth. They later found it to be an effective remedy for hair loss in men. The drug is also marketed under the brand names Proscar and Propecia.
Androgenetic alopecia (AGA) or male-pattern hair loss (MPHL) is the most common cause of hair loss in men. They are more susceptible to it than their female counterparts. ⅔ of men by the age of 35 compared to ⅓ by the age of 40 in females.
Despite being a shared issue, how hair loss occurs varies between the genders. Hair loss in men adopts an ‘M’ pattern starting above both temples. The hairline recedes, and there is thinning in the crown area. Partial or complete baldness occurs if left untreated.
Women with female-pattern hair loss (FPHL) experience thinning all over the scalp. Unlike men, complete hair loss is unlikely.
Testosterone is an androgen hormone. It's responsible for several crucial processes in the male body including libido regulation, and bone and muscle development among others.
In males, the 5α-reductase enzyme metabolizes up to ten percent of testosterone. This gets converted to Dihydrotestosterone (DHT), a more powerful androgen hormone.
DHT attaches to the hair follicles causing shrinkage, weakness, and eventual death. This process is called ‘miniaturization.’ It’s characterized by a reduction in the anagen or growth phase of the hair follicle and extension of the telogen or dormant or resting phase. Those genetically predisposed to hair loss have a higher sensitivity to DHT.
Increased amounts of DHT also cause the group of cells known as the prostate to grow in size, a condition known as Benign Prostatic Hyperplasia (BPH). It’s location between the bladder and the penis results in issues like urinary incontinence and dysuria (pain with urination) among others.
Finasteride acts as a selective inhibitor of the enzyme that metabolizes testosterone. This alters its function and reduces the amount of DHT produced.
Minor side effects include itching of the scalp, dandruff, and headaches. Adverse side effects are mainly sexual including a loss of libido, challenges developing and maintaining an erection, and abnormal ejaculation, which is some of the adverse effects experienced while on the medication. These may persist up to three months following treatment cessation but occur in less than 4% of those taking the drug.
A prescription is required for Finasteride. The standard oral dose is 1 milligram (mg) daily. Exceeding this does not accelerate hair growth. Minoxidil (Rogaine), a topical solution that promotes circulation in the scalp may also be given in severe cases.
The medication is for men over the age of 18. Children, women, and men under 18 years of age should avoid ingesting or coming into contact with it as it can be absorbed transdermally. Wash the area of contact immediately with warm water soap if this occurs.
Studies show Finasteride reduces MPHL by 80% in the majority of users.
Temporary, accelerated hair loss is common in the first three months of treatment as miniaturized follicles make way for thicker and stronger ones. Positive growth starts happening around the six-month mark. Discontinue treatment if there are no signs of improvement after twelve months of continuous use.
The efficacy of the medication is influenced by the age and overall health of the patient as well a the consistency of treatment. Chances of it working are slim if you are already bald.
Finasteride does not eliminate the underlying cause of (MPHL). Hair loss will resume if treatment stops.