Skip to Content

Finasteride Patient Tips

Written by C. Fookes, BPharm on Aug 01, 2016

How it works

  • Finasteride works by blocking an enzyme called Type II 5α-reductase which is responsible for converting the hormone testosterone into dihydrotestosterone (DHT). The scalp of men who are balding has been found to contain miniaturized hair follicles and increased amounts of DHT compared with men who have a lot of hair.
  • Finasteride reduces scalp concentrations of DHT and appears to interrupt a key factor in the development of androgenetic alopecia (male pattern baldness) in those men who are genetically predisposed.


  • Finasteride is used for the treatment of male pattern hair loss - also called androgenetic alopecia. Finasteride is indicated in MEN only.
  • Finasteride does not affect body levels of cortisol, thyroid hormones, cholesterol or bone mineral density.
  • Evidence reports significant increases in hair count at both 6 and 12 months in men treated with finasteride tablets (an average increase of 107 hairs when compared to placebo [pretend pill] after 12 months). After two years this hair count was maintained, and slightly increased (by an average of 138 hairs over placebo). Most men experienced a slow decline in hair count following the initial improvement; however, hair count was maintained above baseline throughout the 5 years of the studies. Hair loss continued in those men who were assigned a placebo tablet, such that the difference in hair count was 277-hairs at the end of the 5-year study period.
  • No dosage adjustment is needed in men with kidney disease; however, finasteride must be used with caution in men with liver disease.


If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Sexual dysfunction (including decreased libido, erectile dysfunction and ejaculation disorder) has occasionally been reported in men taking finasteride. Side effects are generally uncommon and do not result in drug discontinuation.
  • As with other 5α-reductase inhibitors (such as dutasteride), may slightly increase the risk of prostate cancer development in men aged 55 and over from 1.1% for placebo to 1.5% with finasteride.
  • May cause birth defects, most notably in a male fetus, if used during pregnancy (finasteride has not proven to be effective in women anyway).
  • May cause decreases in serum prostate specific antigen (PSA) which should be taken into account in men with cancer whose PSA levels are being monitored. Reductions in PSA levels of about 50% have been reported in older men.
  • Finasteride may not be effective for bi-temporal recession (often referred to as the "widow's peak").
  • Finasteride tablets should not be used in women. No improvement in hair counts, or patient or investigator assessment were noted in 137 postmenopausal women with androgenetic alopecia treated with Finasteride tablets for 12 months.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

Bottom Line

Finasteride is effective at temporarily reversing hair loss in men with androgenetic alopecia, with few side effects. However, the amount of hair regrowth is greatest during the first two years of use. A reversal of hair regrowth is seen within 12 months of discontinuation of finasteride.


  • Finasteride may be administered with or without meals. The usual dose is one tablet daily.
  • Daily use of finasteride for at least three months may be required before a benefit is seen.
  • Finasteride tablets must be taken on a daily basis to maintain hair regrowth. Most men experience the biggest hair regrowth in the first two years of taking finasteride. Withdrawal of treatment leads to a reversal of hair gain within 12 months. Re-evaluate benefits of finasteride periodically.
  • Men should report any changes in their breast tissue such as lumps, pain, tenderness, enlargement or nipple discharge.
  • Always read the patient package insert before starting finasteride and each time your prescription is renewed.
  • Finasteride tablets are for MEN only and should not be used by women or children.
  • Tell your doctor you are taking finasteride if your PSA levels are being monitored.

Response and Effectiveness

  • Finasteride suppresses serum DHT concentrations by as much as 65% within 24 hours of an oral 1 mg dose. Levels of testosterone and estradiol circulating within the blood are also reduced by around 15%.
  • Effects on hair regrowth may take up to three months to be seen.


Finasteride [Package Insert] Hetero Labs Limited Revised 04/2016.

  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use finasteride only for the indication prescribed.

  • Disclaimer: Every effort has been made to ensure that this information is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This drug information does not endorse drugs, diagnose patients or recommend therapy. It is an informational resource designed as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of this information. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2017 Revision Date: 2016-08-11 00:00:00