What Are 5-Alpha-Reductase Inhibitors?

• Do 5-Alpha-Reductase Inhibitors Regrow Hair?
• Safety Warnings
• Herbal Options

Research indicates that synthetic pharmaceutical and natural herbal 5-alpha-reductase inhibitors may help treat common androgenetic balding in men and female pattern hair loss in women.⁽³⁰⁾

These include:^(30, 466)

• Dutasteride (also known by the brand name Avodart®)
• Finasteride (also known by the brand name Propecia®)
• Licorice herbal extract
• Pumpkin seed oil
• Saw palmetto (a natural herb)

Both finasteride and dutasteride were originally manufactured and prescribed to treat benign prostate hyperplasia. BPH is a common condition that causes prostate enlargement in older men. These drugs work to treat BPH by blocking one or both types of the 5-alpha-reductase enzyme in the prostate.⁽³⁾

Are 5-Alpha-Reductase Inhibitors a Good Choice to Regrow Hair?

Studies support the effectiveness of both drugs in most cases of common male balding, as well as some women with female-pattern hair losss. According to at least one study, oral finasteride may even work better than 5% topical minoxidil.⁽³⁾

However, minoxidil may be less expensive and its safety for long-term use is well-established. Treatment must be continuous in order to maintain the hormone-blocking effects of these drugs.⁽³⁾

Safety Warnings for Prescription 5-Alpha-Reductase Inhibitors

These drugs are not recommended for women are or might become pregnant, however. 5-alpha-reductase enzyme inhibitors can cause serious birth defects, and the U.S. Food and Drug Administration specifically warns against use or even handling of these drugs by women fit in this category. In fact, they are so potent that some doctors recommend that a woman who wants to become pregnant stop taking 5-alpha-reductase enzyme inhibitors and avoid possible pregnancy for at least six months after stopping.^{(22, 80, 197)}

Potent Herbal 5-Alpha-Reductase Inhibitors

Saw palmetto is a short palm tree native to North American Atlantic coast. Native American Indians used the tree's leaf fibers for many household purposes, and the berries for food and medicine.⁽⁹⁵⁾

Saw palmetto was traditionally a natural herbal remedy for a variety of health conditions caused or affected by androgen sex hormones—including prostate enlargement, male infertility and sexual function, and increasing female breast size.⁽¹⁹⁸⁾

Lab and clinical studies demonstrate that saw palmetto works like finasteride—but without the adverse side effects.⁽⁹⁵⁾

Supplements of pumpkin seed oil and licorice have also been successfully tested in clinical trials. In fact, 2% licorice extract showed better results than 2% minoxidil in regrowing hair.⁽⁴⁶⁶⁾