What is Dutasteride?

Dutasteride is a synthetic drug used to treat hair loss and prostate enlargement in men. Its mechanism of action is to suppress 5-alpha-reductase (5 ar), the enzyme responsible for the conversion of testosterone into dihydrotestosterone (DHT). While male-pattern baldness and benign prostatic hyperplasia (BPH) are both provoked by this biological event, the Food and Drug Administration (FDA) only approves dutasteride to treat the latter in the U.S. However, it is expected that clinical trials currently underway will result in the drug becoming officially FDA approved to treat hair loss too, as well as being approved as a cancer of the prostate drug.

Manufactured by GlaxoSmithKline in the United Kingdom, dutasteride is primarily familiar to Americans as Avodart®. However, it is also marketed under a variety of other names, including the generic forms of Dutagen and Duprost. Avodart is sold as a soft gel capsule that contains dutasteride in the form of a white or yellowish powder. Since this substance is insoluble in water, it is combined and dissolved in the medication with phenolic compounds, such as butylated hydroxytoluene, as well as the inert ingredients glycerin and gelatin. As a treatment for enlarged prostate or BPH, the drug may also be combined with an alpha-blocker, such as tamsulosin.

Dutasteride is considered to be a dual 5-alpha-reductase inhibitor because it suppresses both isoforms of the enzyme. This gives the drug an advantage over similar medications, such as finasteride, which only prevent the release of one. As a result of this enhanced activity, dutasteride is more effective at inhibiting DHT synthesis than finasteride-based medications, otherwise known as Propecia® or Proscar®.

There are also fewer side effects reported with dutasteride than there are with finasteride. In addition, studies have shown that these side effects are usually temporary and tend to diminish over time. The most commonly experienced side effects in the order of frequency from highest to lowest include impotence, decreased interest in sex, difficulty ejaculating, and gynecomastia, or tenderness in the breast.

There is one more consequence sometimes experienced with taking this medication that’s known as Dutasteride Shedding. It is actually more of a normal part of the hair restoration process than it is a side effect. It occurs as the drug stimulates hair follicles to abandon a state of rest and produce new growth. However, while many hairs that have entered into this resting phase are still attached to the follicle, they receive no nourishment and do not grow -- they are essentially dead. This means that many hairs may need to fall out at the same time before any new growth can be seen, a process that can take anywhere from six weeks to two months.