Dutasteride
The History
Dutasteride, originally developed to treat benign prostatic hyperplasia (BPH), was approved by the FDA in 2001 under the brand name Avodart. Like finasteride, it was initially designed to inhibit the 5-alpha reductase enzyme, which converts testosterone into dihydrotestosterone (DHT). Dutasteride gained recognition as a potential treatment for androgenetic alopecia (male pattern baldness) because it inhibits both type I and type II forms of 5-alpha reductase, offering a broader suppression of DHT compared to finasteride. Although not FDA-approved for hair loss in the U.S., it has been used off-label for this purpose and is approved for hair loss treatment in some countries like South Korea and Japan.
The Good
Dutasteride has been shown to be highly effective in reducing DHT levels—by up to 90%—compared to the approximately 60% reduction achieved with finasteride. This greater suppression of DHT can result in better prevention of hair loss and, in some cases, more significant regrowth. Studies have demonstrated that dutasteride outperforms finasteride in terms of hair count and density improvement over a 6–12 month period. Additionally, its effects tend to last longer due to its extended half-life in the body, which allows for steady DHT suppression even with lower doses.
The Bad
Because dutasteride is a stronger DHT blocker, it may carry an increased risk of side effects compared to finasteride. Reported side effects include decreased libido, erectile dysfunction, and reduced semen volume. While these side effects are rare and often reversible upon discontinuation, the stronger action of dutasteride means a slightly higher likelihood of experiencing them. Moreover, its long half-life means it takes longer for the drug to clear from the system, which could prolong side effects in rare cases.
The Ugly
Like finasteride, dutasteride requires long-term use to maintain its benefits. Stopping the medication can lead to a return of hair loss within 3–6 months, undoing any progress made. Additionally, the stronger suppression of DHT has raised concerns about its potential effects on hormonal balance, particularly with prolonged use. It’s essential to discuss these risks with a healthcare provider before starting dutasteride.
How to Get It
Dutasteride is typically prescribed in a 0.5 mg daily dose for BPH, but off-label use for hair loss often involves the same dosage. It is available in capsule form and requires a prescription. Unlike finasteride, dutasteride is not FDA-approved for hair loss in the U.S., so its availability may vary depending on your location and the discretion of your healthcare provider.
Which Works Better: Dutasteride vs. Finasteride?
Studies comparing dutasteride and finasteride have shown that dutasteride provides superior results in terms of hair regrowth and DHT suppression. However, it also carries a slightly higher risk of side effects due to its stronger action. Dutasteride may be a better option for individuals who do not see sufficient results with finasteride or who are experiencing significant hair loss, but its use should be carefully monitored.
