Dutasteride (product name Avodart or Duprost) is a drug used for benign prostatic hyperplasia to improve urinary symptoms, reduce the risk of acute urinary retention, and reduce the need for BPH-related surgical interventions. Dutasteride, being a 5alpha-reductase inhibitor, can also be effective for male pattern hair growth.

Subscribe to a FREE Supplement Research Update newsletter. Once or twice a month we email a brief abstract of several studies on various supplements and natural medicine topics, including dutasteride side effects and benefit, and their practical interpretation by Ray Sahelian, M.D.

Dutasteride and Prostate

Compared with placebo, dutasteride has been shown to significantly improve BPH symptoms, reduce the incidence of acute urinary retention and BPH-related surgery, and improve BPH-related quality of life. Few published data exist comparing dutasteride with finasteride. Clinical trials, sponsored primarily by the manufacturer, have shown dutasteride to be an effective treatment of prostate enlargement compared with placebo and to likely be similar to finasteride or Proscar. Further studies are needed to gain a more clear understanding of any clinically significant differences between dutasteride and finasteride.

2006 Dutasteride and Prostate Study

Dutasteride appears to be beneficial in treating benign prostatic hyperplasia (BPH). Dr. Francois Desgrandchamps of Hopital Saint Louis, Paris and associates note that dutasteride has done well in research trials, providing significant improvements in symptoms and urinary flow, and has led to significant reductions in prostate size and the need for surgery. In addition, dutasteride appeared to be well tolerated with few side effects. To find out if these benefits extended to patients in routine clinical practice, the researchers conducted a study with 366 men with BPH. All received dutasteride daily for 6 months. By the end of the study, 72 percent of patients had at least a 3-point reduction in the International Prostate Symptom Score, a standard measure of BPH symptoms. On average, the score fell from 15 at the start of the study to 10 at 12 weeks and to 9 after 24 weeks. Dutasteride appeared to be well tolerated. BJU International, July 2006.

How does Dutasteride Work?
Prostate growth is caused by a hormone in the blood called dihydrotestosterone (DHT). Dutasteride lowers DHT production in the body, leading to shrinkage of the enlarged prostate in most men. Dutasteride, is a dual 5alpha-reductase inhibitor for the treatment of benign prostatic hyperplasia. Dutasteride differs from finasteride as it inhibits both isoenzymes of 5alpha-reductase and results in near-complete suppression of serum dihydro-testosterone. Similar to finasteride, dutasteride reduces serum prostatic specific antigen by approximately 50% at 6 months and total prostate volume by 25% in 2 years. Randomised, placebo-controlled trials conducted over 2 years have shown the efficacy of dutasteride in symptomatic relief, and peak urinary flow rate, and reduction of acute urinary retention events and the need for surgery.  Dutasteride has been shown to possess tumor regression properties in vitro and its role in chemoprevention of prostate cancer is being evaluated in the ongoing Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial.

Dutasteride and Hair loss
Dutasteride is being tested for hair loss. Dutasteride has shown benefit in restoring hair to bald men. Dutasteride interferes with 5-alpha-reductase enzymes that break down the male hormone testosterone and turn it into dehydrotestosterone (DHT) - which causes hair to thin dramatically in later life. Dutasteride may have better DHT supression results than finasteride both Propecia and Proscar). Dutasteride has shown promise as a hair loss treatment for those with male pattern baldness. Dutasteride is developed by GlaxoSmithKline. Dutasteride is a dual 5-alpha-reductase inhibitor that is indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. Dutasteride is currently in a trial phase for the treatment of male pattern baldness.

The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride.
J Am Acad Dermatol. 2006 Dec;55(6):1014-23.
Our aim was to evaluate the efficacy of the type 1 and 2 5alpha-reductase inhibitor dutasteride in men with male pattern hair loss. Four hundred sixteen men, 21 to 45 years old, were randomized to receive dutasteride 0.05, 0.1, 0.5 or 2.5 mg, finasteride 5 mg, or placebo daily for 24 weeks. Dutasteride increased target area hair count versus placebo in a dose-dependent fashion and dutasteride 2.5 mg was superior to finasteride at 12 and 24 weeks. Scalp and serum dihydrotestosterone levels decreased, and testosterone levels increased, in a dose-dependent fashion with dutasteride. Dutasteride increases scalp hair growth in men with male pattern hair loss. Type 1 and type 2 5alpha-reductase may be important in the pathogenesis and treatment of male pattern hair loss.

Dutasteride Side Effects

The most common side effects of dutasteride include ear, nose, and throat infection; malaise; headache; dizziness; and musculoskeletal pain. Just as finasteride has the potential to interfere with sexuality and libido, it is possible that dutasteride may have similar sexual drive reducing potential. The main dutasteride sexual side effects are erectile dysfunction, decreased libido, gynacomastia and ejaculation disorders.

Dutasteride Questions
Q. I sent you, under separate email, a “Live Science” article regarding a study that indicates that men with low testosterone die sooner. I am an “over 50” male with an enlarged prostate and relatively high PSA reading which has proven to be non-cancerous. I am taking dutasteride which has apparently shrunk my prostate to a reasonable size and the symptoms of frequent urination and difficulty in starting urination have gone away. The side effects seem to be a decreased semen production, but my sex drive is still there (not like when I was 25 though). If the article regarding low testosterone is correct, and if my assumption about dutasteride is correct, that it lowers testosterone levels, could dutasteride possibly shorten my life span?
     A. As far as we know, dutasteride blocks the conversion of testosterone to DHT, rather than decreasing testosterone levels. The long term health consequences of regular dutasteride use, and reduction of DHT levels, are not known. Just to be on the safe side, it is best to use dutasteride in as low a dosage as possible and perhaps taking occasional breaks from use. This has to be done in agreement with your prescribing doctor.

Q.  have a quick question concerning dutas. I am experiencing some hair loss now for a few years. Still have a full head of hair but it is definitely starting to thin. About a month ago I ordered Dr. Reddys dutas and started to take 5 mg a day of dutas. Its been about 4 weeks and it seems like I am shedding a lot of hair then before I started the drug. Is this normal and for your opinion do you think it i should stop soon? I know nothing is proved but off the record does this drug improve hair loss at all? What have you heard or seen as you have done your research through the years? Please let me know if I am wasting my time with this drug.
   A. According to a website, "Dutas is Dutasteride and is a generic form of Avodart. Dutas is made by Dr Reddy's Laboratory in India. Dr. Reddy's Laboratories Ltd has launched Dutas for the treatment of enlarged prostate. Dr. Reddy's is the first company to launch this drug in India." We are not familiar with this version of dutasteride so we don't know if it is effective.