There are several medical therapies that can slow down or stop the progression of hair loss. In this article, we will discuss the four of the most commonly used medical therapies: minoxidil, finasteride, dutasteride, and spironolactone including the benefits and side effects associated with each medication.

Minoxidil:

Minoxidil is a prescription medication that was originally used to treat high blood pressure. Patients taking minoxidil for blood pressure noticed they were developing more hair on their body. In the 90s the medication was formulated as a topical solution. More recently, minoxidil has also been prescribed in a lose dose oral form to provide hair growth benefits without effecting blood pressure.  Minoxidil works by increasing the blood flow and nutrients to the hair follicles, which helps to promote hair growth. It is an effective treatment for androgenic alopecia in both men and women.

Solution/foam:

Minoxidil topical solution and foam is available over-the-counter in 2% and 5% formulations and by prescription in higher strengths. It should be applied once or twice daily. The most common side effects of minoxidil include itching and redness of the scalp. Patients can also develop hypertrichosis or excess unwanted hair (typically on the beard/chin/mustache).

Oral:

Minoxidil is available by prescription in a tablet form. Low dose formulations provide the benefits of hair growth without having significant effects on blood pressure. Rarely patients may experience light headiness and may need to have their dose adjusted. In the first month patients may experience a slight increase in shedding as more hairs re-enter the growth phase. Minoxidil is not associated with erectile dysfunction. Rarely leg swelling can occur. Hypertrichosis can occur and is dose dependent.

Finasteride

Finasteride is a prescription medication that is FDA-approved for the treatment of androgenic alopecia in men. It works by inhibiting the production of DHT, which is a hormone that plays a role in hair loss. Finasteride inhibits DHT by blocking the enzyme 5-alpha-reductse (type 2) which normally converts testosterone to DHT. The half life of finasteride is 6 to 8 hours meaning the medication is metabolized within a day or two. Finasteride is available in tablet form and should be taken once daily. Most patients tolerate finasteride without side effects. In the first year of therapy roughly 2% of men report decreased libido, erectile dysfunction, and ejaculatory dysfunction. After the first year this drops to less than 1%.

Dutasteride

Dutasteride is a prescription medication that is FDA-approved for the treatment of androgenic alopecia in men. It works by inhibiting the production of both DHT. Specifically dutasteride inhibits the enzymes 5-alpha-reductase (type I and II). It has a half life of approximately 5 weeks. The combination of a longer half life and inhibition of two types of 5-alpha-reductase enzymes results in significantly more inhibition of DHT than with finasteride. Dutasteride is available in capsule form and should be taken once daily. Side effects are similar to finasteride in that most patients tolerate dutasteride without side effects. Rarely some men report decreased libido, erectile dysfunction, and ejaculatory dysfunction.

Spironolactone

Spironolactone is a prescription medication that is FDA-approved for the treatment of androgenic alopecia in women. It was originally developed as a blood pressure medication (diuretic) however it has anti-androgen properties. Androgens are hormones that play a role in hair loss. While spironolactone does have anti-androgen properties, it is less effective at inhibiting DHT than 5-alpha-reductase inhibitors like finasteride or spironolactone. Spironolactone is available in tablet form and should be taken once daily. The most common side effects of spironolactone include irregular periods, weight gain, and headaches.