What are Finasteride side effects in women?

The side effects of finasteride in women have been  delineated by the other Physicians. It has been my experience that oncologists do not approve of using finasteride in women who have had breast cancer. 

Woman do nor use it. Finasteride causes child birth defect and anomalies of baby if used in child bearing age of woman .if you are in menapouse  you may try to use 5 mg finasteride daily.

Thank you for your question. There was a study 5 years ago using finasteride 5 mg daily in women. Previous findings over 15 year ago showed finasteride 1 mg daily to be ineffective in women. The findings were that with the 5 mg dose over 90% of women self reported a huge or moderate response rate for preserving and restoring hair. 8 of the 43 women had decreased libido, 4% had headache or nausea which resolved. This study was limited in size and not a double blinded study which is the gold standard. For the time being, the FDA has only approved finasteride for the treatment of androgenetic alopecia in men. Treatment of women is considered an "off-label use". There is the risk for severe fetal malformations in pregnant women and finasteride should not be given to women of child bearing capacity. In men, the combination of finasteride and minoxidil (Rogaine) is more effective than single therapy.It is best to consult with a hair restoration specialist to get their recommendations for restoring and preserving your hair.I hope this was helpful - Dr. Moore.

Finasteride is not FDA approved for women. Any such use is therefore off label and you'll want to be guided by a knowledgeable and experienced physician if this is a route you wish to take. Depending in your current age, type of hair loss and medical history and family history this may or may not be a good option.
Side effects of finasteride in women include, but are not limited to: harm to a fetus (finasteride can not be used in pregnancy), fatigue, weight gain, depression, anxiety, decreased libido, sexual dysfunction, hair shedding, breast tenderness, breast enlargement. Even changes in blood tests like platelets and muscle enzymes are possible - albeit rare.  Be sure to review thoroughly with your physician. Finasteride can be effective for some women and I continue to prescribe it in specific situations. You may decide together with your physician to consider other antiandrogens like spironolactone. 

I am unaware of many side effect of this drug that have been reported in women. Logically, body hair growth headaches and hot flashes may occur as this happens in post menopausal women